J. Phys. Chem. C 2010, 114, 15315–15330 15315 Theoretical Description of Electromagnetic Nonbonded Interactions of Radical, Cationic, and Anionic NH2BHNBHNH2 Inside of the B18N18 Nanoring M. Monajjemi,*,†,# V. S. Lee,‡ M. Khaleghian,§ B. Honarparvar,† and F. Mollaamin⊥ Department of Chemistry, Science and Research Branch, Islamic Azad UniVersity, Tehran, Iran, Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry and Center for InnoVation in Chemistry, Thailand Center of Excellence in Physics (ThEP), Faculty of Science, Chiang Mai UniVersity, Chiang Mai, Thailand, Department of Chemistry, Islamshahr Branch, Islamic Azad UniVersity, Islamshahr, Iran, and Department of Chemistry, Qom Branch, Islamic Azad UniVersity, Qom, Iran ReceiVed: May 11, 2010; ReVised Manuscript ReceiVed: June 27, 2010 The electromagnetic nonbounded interactions of the NH2BHNBHNH2 molecule inside of the B18N18 ring have been investigated with hybrid density functional theory (B3LYP) using the EPR-III and EPR-II basis sets for a physicochemical explanation of electromagnetic nonbounded interactions within these nanosystems. Optimized structures and hyperfine spectroscopic parameters such as total atomic charges, spin densities, electrical potential, and isotropic Fermi coupling constants of radical, cationic, and anionic forms of the NH2BHNBHNH2 molecule in different loops and bonds of the B18N18-NH2BHNBHNH2 systems have been calculated. The correlations between structural, electronic, and spectral properties have been contributed to identify the characteristics of hyperfine electronic structure. Besides structural characteristics, the lowest unoccupied molecular orbital and the highest occupied molecular orbital for the lowest energy have been derived to examine the structural stability of the B18N18-NH2BHNBHNH2 systems. We have also carried out the calculation for the alanine-glycine amino acids coupled with the NH2BHNBHNH2 molecule inside of the B18N18 ring (ALA-NH2BHNBHNH2-GLY) and obtained quantized transitional frequencies among the forms of radical, anionic, and cationic. In a similar way, in B18N18-NH2BHNBHNH2, the three frequencies have been yielded as νr-c ) 486948.498 GHz, νa-c ) 1792900.812 GHz, and νr-a ) 2507076.816 GHz. It can be seen that all observed frequencies appeared in the IR and macrowave regions. It seems that the B18N18-NH2BHNBHNH2 nonbonded system can be used for the measurement of rotational spectra related to electrical voltage differences existing in a part of biomacromolecules. The radial coordinate of the dipole moment vector (r) as well as the voltage differences (∆V) and relative energies (∆E) of the radical, anionic and cationic forms of the NH2BHNBHNH2 in the B18N18-NH2BHNBHNH2 system exhibited Gaussian distribution. The expectations of the ∆E and ∆V and r have been calculated from the Gaussian curves, which have been fitted by various eigenvalues. In addition, the natural bond orbital (NBO) analysis has been performed, which was informative to reveal some important atomic and structural features. Also, analysis of the NQR hyperfine structure of the B18N18-NH2BHNBHNH2 system has been performed in terms of the electric field gradient at each nitrogen nucleus, and the changes in the extent of electric charge distribution that accompanies complex formation have been explored. 1. Introduction Heterofullerenes became a subject of research interest soon after the establishment of fullerene research itself.1-3 The fullerenes containing boron and/or nitrogen atoms [refs 4-13 of ref 6] represent one distinguished class, though other elements have been combined with the fullerenes too.4-6 Boron nitride (BN) is a synthetic III-V compound with extraordinary mechanical, thermal, electrical, optical, and chemical properties widely applied for technological purposes.1 Since BN units are isoelectronic with hexagonal BN possessing a graphene-like layered structure, BN becomes the natural * To whom correspondence should be addressed. E-mail: m_monajjemi@ cm.utexas.edu. † Science and Research Branch, Islamic Azad University. ‡ Chiang Mai University. § Islamshahr Branch, Islamic Azad University. ⊥ Qom Branch, Islamic Azad University. # Visiting Researcher: Department of Chemistry and Biochemistry, Institute for Theoretical Chemistry, The University of Texas at Austin, Austin, TX. candidate to form heterofullerenes, which results in a certain isomorphism. BN crystalline samples were synthesized at room temperature and atmospheric pressure as structures containing hexagonal sp2-bonded sheets isomorphic with graphene.7 BN nanomaterials are expected in extentive application due to the good stability at high temperatures with high electronic insulation in air.8 Despite the carbon nanotubes, BN nanotubes are constant band gap materials and thus provide an attractive opportunity for practical applications.9 The wide range of their electronic properties from metallic to wide-gap semiconductors, depending on their chemical composition, makes them suitable candidates for nanosize electronic devices.10,11 Due to the similarity between B-N and C-C units, a lot of effort has been devoted to BN fullerene-like materials in recent years, which have excellent properties such as heat resistance, insulation, and structural stability.12,13 Several studies have been made on BN nanomaterials such as BN nanotubes, BN nanocapsules, and BN clusters since they have excellent properties such as heat resistance in air and insulation, and these nano- 10.1021/jp104274z 2010 American Chemical Society Published on Web 08/23/2010 15316 J. Phys. Chem. C, Vol. 114, No. 36, 2010 Monajjemi et al. Figure 1. (a) The geometrical structure of the generation of our considered armchair nanotube (n ) m ) 6) through folding of a section of a graphene sheet. (b) The optimized structure of the B18N18 ring at the B3LYP/EPR-III level of theory. (c) The optimized structure of alanineNH2BHNBHNH2-glysine at the B3LYP/EPR-III level of theory. particles are expected to be useful as electronic devices, high heat resistance semiconductors, and insulator lubricants.14-17 From the experimental standard formation enthalpy, the energies of hybridized sp2 and sp3 B-N bonds are known to be stronger in comparison with those of B-B and N-N bonds, namely, 4.00, 2.32, and 2.11 eV, respectively.18 Along with the experimental efforts, extensive theoretical studies have also been carried out on BN fullerenes to understand their relative stability and size dependence of the properties.19-21 Several investigations have dealt with the possibility of inorganic analogues of the fullerene cages that would be constructed entirely of BN pairs.22-25 Since the thermodynamic conditions for growth of BN nanotubes from nuclei are still not well-defined, comprehensive theoretical simulations on these nanotubes continue to attract enhanced attention, and the lack of theoretical thermodynamic data precludes a more detailed analysis.26 These nanotubes are found to be chiral or nonchiral; however, a preference toward the armchair and zigzag configurations is suggested. Electron energy loss spectroscopy yields a B/N ratio of approximately 1 and a perfect chemical homogeneity.27 This paper focuses on the tubes generated with the single-wall boron nanotube (SWBNNT) from a MWNT ) 1 as an armchair nanotube (n,m) with chirality n ) 6, m ) 6 and with a tube NH2BHNBHNH2 Inside of the B18N18 Nanoring length of 3 Å. The schematics of the generation of the considered nanotube through folding of a section of a graphene sheet and the optimized structure of the alanine-B18N18-glysine are displayed in Figure 1, where C ) na1 + ma2 ) (n,m); a1 and a2 are the primitive lattice vectors of the graphene, and n and m are integers.28,29 2. Computational Details The geometry of the B18N18-NH2BHNBHNH2 system has been optimized by Becke’s hybrid three-parameter exchange functional and the nonlocal correlation functional of the Lee, Yang,and Parr (B3LYP) method30,31 with the EPR-III and EPRII basis sets of Barone.32 The Gaussian quantum chemistry package was used for all calculations.33 The optimization was done along with a frequency calculation to verify that the geometry was a real minimum without any imaginary frequency. EPR-II is a double-ζ basis set with a single set of polarization functions and an enhanced s part, (6,1)12,21 for H and (10,5,1)12,13,23 for B-F. EPR-III is a triple-ζ basis set including diffuse functions, double d-polarizations, and a single set of fpolarization functions. Also in this case, the s-part is improved to better describe the nuclear region, (6,2)10,13 for H and12,13,24,27 for B-F. Vibrational frequencies have been calculated at the B3LYP/EPR-II level of theory to verify that the geometry was a real minimum without any imaginary frequency and analyze the thermochemical functions including enthalpies and Gibbs free energies.34 In the current study, we have performed systematic firstprinciple calculations on the atomic and electronic nanostructures of the B18N18-NH2BHNBHNH2. Structure, stability, and spectroscopic properties of this system have been explored. An attempt is made to explain the anomalous nonbounded interactions of the NH2BHNBHNH2 molecule inside of the B18N18 ring with a quantized nanospectrophotometer detection of various quantized parameters of a given alanine-glysine amino acid. In other words, a supposed picture of the electronic structure of these magnetically unusual nanoparticles encouraged us to imagine such a nanosystem as a quantized transition system which would induce an electromagnetic field through electrostatic interaction of the NH2BHNBHNH2 molecule inside of the B18N18 ring and also has the capability of detecting the quantized parameters of the system considered as well as other bimolecular amino acids which can be coupled with this system. In other words, there is mutual electrostatic interaction between the NH2BHNBHNH2 molecule and the B18N18 ring, which yields the quantization of the radial component of the dipole moment vector (r) as well as the voltage differences (∆V) and relative energies (∆E) of the NH2BHNBHNH2 radical, cation, and anion. The NH2BHNBHNH2 molecule moves among quantized coordinates of the radial component (r) of the dipole moment as well as energy levels, and then, a specific spectrum would appear. Therefore, when the NH2BHNBHNH2 is coupled with two points of the amino acids inside of the B18N18 ring, different radical, cationic, and anionic forms of the NH2BHNBHNH2 are expected to appear due to the potential energy difference or voltage caused by the NH2BHNBHNH2. Therefore, investigation of the electrostatic interaction of the NH2BHNBHNH2 with its surrounding ring along with exploring the variations of different physicochemical properties such as dipole and quadropole moments as well as NBO and NQR parameters of the B18N18NH2BHNBHNH2 system would be of great importance. It has been demonstrated how this mechanistic question may be addressed in the framework of modern electronic structure methods, specifically with the B3LYP hybrid density functional J. Phys. Chem. C, Vol. 114, No. 36, 2010 15317 method and EPR-III basis set. Natural bond orbital (NBO) analysis has been employed to analyze the calculated electron density in terms of localized Lewis structure and resonance theoretical concepts.35 As a check on the quality of the calculated geometrical parameters and their stability with respect to the level of theory, the HOMO and the LUMO differences have been explored. In the course of determining hyperfine parameters and relating them to the underlying electronic structure of the considered system, anisotropic magnetic effects have been explained and provided useful information on the interaction characteristics.26 The HOMO corresponds to a combination of lone pair orbitals on the N atoms as well as the LUMO, which is characterized by large contributions from vacant p orbitals on B atoms with some admixture of N-based orbitals having been calculated.36 The NBO analysis has been performed by using NBO as implemented in the Gaussian quantum chemistry package.35 The asymmetry parameters as well as the quadrupole coupling constant of nitrogen atoms involved in the B18N18NH2BHNBHNH2 system, which have been correlated with atomic charges, have been computed. The spin-spin magnetic hyperfine Hamiltonian as a part of the molecular Hamiltonian can be presented as eq 1 HSS hf ) µ0 gµ µ 4π S B N ∑ { gR 3 i,R f f (Sfi · rf iR)(IR · riR) 5 riR - (Sfi · IfR) 3 riR + } 8π f f f × (Si · IR) · δ(3)(riR) 3 (1) where gS and µB are the free electron g-factor and the Bohr magneton, respectively, gS and µB are the nuclear g-factor and the nuclear magneton, SfISi and IfR are “the spins of the electron i and the nucleus R, and rf IR represents the distance between an electron i and nucleus R; i and R are referred to as electrons and magnetic nuclei, respectively. This operator acts both in the state space of the electrons and in the state space of the nuclei. The anisotropic dipole-dipole interaction between the electronic and nuclear spin magnetic moments is represented by the first and the second parts of the considered equation. The last term, the isotropic Fermi contact term, arises from the magnetic field inside of the nucleus, created by its magnetic moment. The terms in the effective Hamiltonian are obtained after integration over electronic spatial coordinates; each term contains angular momentum operators and molecular parameters.37 Th isotropic Fermi contact constant bF (in MHz) is defined by bF ) 2µ0 g g µ µ |Ψ(0)| 2 3h S N B N where bF ) b + c/3. Thus, the basic quantities that determine the HF interaction at the Nth nucleus are those in brackets and |Ψ(0)|N2 . The ab initio calculated isotropic constant, bF ) (2µ0/ 3h)gSgNµBµNPS(N), directly depends on the Fermi contact spin density function per unpaired electron at a nucleus.36 3. Results and Discussion The aim of this section is to first discuss the different aspects of the electronic structure of the B18N18-NH2BHNBHNH2 15318 J. Phys. Chem. C, Vol. 114, No. 36, 2010 Monajjemi et al. TABLE 1: Calculated Relative Corrected Interaction BSSE Energy (kcal/mol) for Cationic, Radical, and Anionic Forms of NH2BHNBHNH2 in the B18-N18-NH2BHNBHNH2 System within Transition ∆E (kcal/mol) B18N18-NH2 BHNBHNH2 transition (Å) anion cation radical 0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 0 0.4029 1.7404 3.2098 4.2482 4.6999 5.0443 5.2242 5.0070 4.2051 2.9775 0 0.3367 1.4300 2.4105 2.6559 2.2783 1.4876 0.7574 0.2040 0.1613 0.0923 0 0.1352 1.2544 2.4820 3.6512 3.8760 3.7206 3.3487 2.5572 1.5174 0.6075 system for further validation of theoretical results to increase their usefulness in practical applications or for pre-experimental modeling. Second, we have explored the electromagnetic nature of the B18N18-NH2BHNBHNH2 system by calculating the following parameters, which provide valuable information on the interaction characteristics. 3.1. Relative Energies. To verify the structural stability of our considered B18N18-NH2BHNBHNH2 system, we have optimized the B18N18-NH2BHNBHNH2 system using DFT method (B3LYP) with both EPR-II and EPR-III basis sets. Undoubtedly, since we have focused on electromagnetic induction of NH2BHNBHNH2 inside of the B18N18 ring, employing these employed basis sets seemed useful and helped us find logical relationships between obtained data. The calculated energy (Hartree), relative energy (kcal/mol), and BSSE (kcal/ mol) corrected interaction energy (kcal/mol) for cationic, radical, and anionic forms of NH2BHNBHNH2 in the B18N18NH2BHNBHNH2 system within transition are compared in Table 1. Strikingly, despite the intrinsic linearity of NH2BHNBHNH2 in different radical, cationic, and anionic forms, in this step, the obtained optimization results confirmed the stability of the B18N18-NH2BHNBHNH2 system, and the NH2BHNBHNH2 molecule was located strictly in the center of the B18N18 ring vertically. According to the frequency calculation at the B3LYP/EPR-II level of theory, observing no negative frequency as well as obtaining thermochemical functions such as ∆G ) -67.7929888325 kcal/ mol and ∆H ) -124.401248337 kcal/mol confirmed the structural stability of the B18N18 ring. This effect is probably due to the large dipole moments of the B-N bonds, which preferentially enhance the ring stability. Regarding the system’s stability within transitions and rotations of radical, cationicm and anionic forms of NH2BHNBHNH2, it is notable that the obtained barrier energies for the radical, cationic and anionic forms were 3.876, 2.655, and 5.224 kcal/mol, respectively. The graphs of rotational and transition energy barriers of radical, anionic, and cationic forms of NH2BHNBHNH2 in the B18N18-NH2BHNBHNH2 system are displayed in Figure 2. To account for these observations, two observed points are notable. First, for radical, anionic, and cationic forms of NH2BHNBHNH2, the most stable condition has been observed in the case that NH2BHNBHNH2 is located exactly in the center of the B18N18 ring, that is, the coordination of nitrogen atoms was (0,0,0). Second, the reported BSSE data revealed that despite insignificant changes of barrier energies based on the plotted graphs, the entire trend has not changed essentially from that of the first energy calculations. These obtained results Figure 2. The graphs of the rotational and transitional BSSE energy barriers of NH2BHNBHNH2 in the B18N18-NH2BHNBHNH2 system. motivated us to investigate the rotation of NH2BHNBHNH2. Therefore, we have rotated the center of NH2BHNBHNH2 around one of its axes. In this case, the barrier energy for the radical form was significant (48.5091 kcal/mol). On the basis of such a considerably high barrier energy, we have observed that the radical form of NH2BHNBHNH2 strongly resists under this rotation and exhibits no tendency for rotation in the horizontal state. It has been understood that the only possible movement which probably caused the system’s structural distortion was internal rotation of the radical form of NH2BHNBHNH2 inside of the ring. It is evident that with such a high barrier energy, we could not expect any rotation. According to the plotted rotational graph (Figure 1), it has been found out that the energy barrier of the NH2BHNBHNH2 radical stands as the highest value, and the following trend could be observed NH2BHNBHNH2 (radical) > NH2BHNBHNH2 (anion) > NH2BHNBHNH2 (cation) 3.2. HOMO-LUMO Gap of the System. The LUMOHOMO band gap is a gap between the LUMO (the lowest unoccupied molecular orbital) and HOMO (the highest occupied molecular orbital).38 BN nanotubes have a wide band gap (E) of ∼6 eV and nonmagnetism independent of the tube diameters. The large LUMO-HOMO gap is often regarded as a molecule stability condition.39 More sophisticated treatment of large gaps is seen to occur for systems with high relative stability.40 The band gap of the B18N18-NH2BHNBHNH2 system as the relative differences in the energy of the HOMO and the LUMO is reported in Table 2. According to the results in Table 2, in anionic and radical forms of the NH2BHNBHNH2 molecule, the system showed the highest structural stability compared with the cationic state. In other words, the obtained values for the anionic and radical forms NH2BHNBHNH2 Inside of the B18N18 Nanoring J. Phys. Chem. C, Vol. 114, No. 36, 2010 15319 TABLE 2: Band Gap of the B18N18-NH2BHNBHNH2 System As the Relative Differences in the Energy of the HOMO and LUMO in Atomic Units band gap (HOMO-LUMO) (Hartree) coordinates anion cation radical 0.0,0.0,0.0 0.0,0.0,10.0 0.0,0.0,30.0 0.0,0.0,50.0 0.0,0.0,70.0 0.0,0.0,90.0 0.0,0.0,110.0 0.0,0.0,130.0 0.0,0.0,150.0 0.0,0.0,170.0 27.07986 27.08589 27.0925 27.08153 27.08313 27.08313 27.08092 27.08205 27.08533 27.08011 0.02235 0.02186 0.0161 0.18398 0.02201 0.02128 0.0231 0.02202 0.02202 0.02355 26.86293 26.87004 26.86282 26.86311 26.86818 26.87556 26.86287 26.86627 26.86849 26.86282 were 26-27 Hartree, which were significantly different from those of the cationic form (0.0161-0.18339 Hartree). In these anionic and radical cases, especially in the anionic form at the 0,0,30 coordinate, the highest HOMO-LUMO was at 27.0925 Hartree. After inspecting the highest HOMO-LUMO band gaps in all three radical, anionic, and cationic forms, it seems that in all three considered cases, the highest ∆(HOMO-LUMO) values and the highest stability occurred in the center coordinates and with the B18N18 ring. Therefore, in the cation, anion, and radical at the 0,0,50, 0,0,30, and 0,0,90 coordinates, the highest HOMO-LUMO band gaps were 0.18398, 27.0925, and 26.87556 Hartree, respectively. It is understood that in the case of the anionic form at the 0,0,70 and 0,0,90 coordinates, for the cationic form at 0,0,130 and 0,0,150, and for the radical form at 0,0,30 and 0,0,170, the same HOMO-LUMO band gaps could be observed. 3.3. Natural Bond Orbital (NBO) Analysis. The concepts of natural atomic orbital (NAO) and NBO analyses are useful for distributing electrons into atomic and molecular orbitals used for the one-electron density matrix to define the shape of the atomic orbitals in the molecular environment and then derive molecular bonds from electron density between atoms. The NAOs will normally resemble the pure atomic orbitals and may be divided into a natural minimal basis, corresponding to the occupied atomic orbitals for the isolated atom, and a remaining set of natural Rydberg orbitals based on the magnitude of the occupation numbers. The minimal set of NAOs will normally be strongly occupied, while the Rydberg NAO usually will be weakly occupied. There are as many NAOs as the size of the atomic basis set, and the number of Rydberg NAOs thus increases as the basis set is enlarged .The results of NBO analysis at the B3LYP/EPRIII level of theory are listed in Table 3. At each considered coordination, the bonding and antibonding coefficients of s and p orbitals of B-N bonds were 0.5 and 0.8. However, for both the B37-N38 and B39-N40 bonds, the constant coefficients of 0.3 and 0.9 have been yielded. On the basis of the constant values of the coefficients of a linear combination of s and p orbitals of different bonds (0.5 and 0.8), a specific voltage difference could be expected. It is observed that the percent of s and p orbitals for different bonds of the NH2BHNBHNH2 anion in the B18N18NH2BHNBHNH2 system at all coordinations refers to sp2 hybridization for B as well as sp3 hybridization for the N atom, which is in agreement with the intrinsic sp2 hybridization of B and N atoms. The obtained relationship between NBO and ∆V values of different bonds of the B18N18-NH2BHNBHNH2 system revealed that in the case of the NH2BHNBHNH2 radical, the closeness of the obtained ∆V values (55.245 au) derived by EPR calculations was the lowest value of ∆V compared with those of the NH2BHNBHNH2 cation and anion. In other words, the average value of ∆V in the case of the NH2BHNBHNH2 radical low average (∆V ) 55.245 au) revealed the sharp Gaussian distribution and could be related with the constant bonding molecular orbital coefficients. Meanwhile, the opposite behavior has been seen especially for the NH2BHNBHNH2 cation. It is notable that these values were in accordance with the estimation of the sp2 hybridization of the B atom derived by NBO analysis, while such a direct relationship has not been observed for the NH2BHNBHNH2 cation and anion. 3.4. Nuclear Quadrupole Resonance Parameters. The results obtained in the hitherto studies confirmed the usefulness of NQR spectroscopy for determination of physical and chemical properties of compounds and prediction of their chemical activity. Moreover, the spectroscopic EPR and NQR parameters characterizing the electronic effects are correlated with the activity of the B18N18-NH2BHNBHNH2 system studied. The information inferred from the NQR study on the local electron density distribution together with analysis of the charge distribution by the density functional methods provided suitable means for determination of reactive sites of the B18N18NH2BHNBHNH2 system and hence indicated possible promising directions to be followed in nanodevices.41,42 The asymmetry parameters and quadrupole coupling constants of nitrogen atoms of the B18N18-NH2BHNBHNH2 system at different coordinates are listed in Table 4. It can be seen that the coupling constants of nitrogen atoms of all different coordinates increased from 0,0,0 up to a maximum point and then decreased to the lowest value. As a whole, it is understood that the maximum amount of charge density on the nitrogen nuclei was concentrated at the edges and in the center of the B18N18 ring, and at these regions, the lowest asymmetry parameters could be observed. Another point is that among nitrogen atoms, the N38 of the anionic form with χ ) 3.773 MHz and the N40 with χ ) 3.578 MHz yielded the highest coupling constant values. It is notable that such a high value of χ and, consequently, a high charge density corresponded to nitrogen atoms of the NH2BHNBHNH2 molecule inside of the ring and at the 0,0,50 and 0,0,30 coordinates for the radical and cationic forms, respectively. 3.5. Nonbonded Interaction of NH2BHNBHNH2 with the B18N18 Ring. In this section, the major point is embedded in the investigation of the electrostatic interaction of NH2BHNBHNH2 with its surrounding B18N18 ring, which forms the basis for more detailed studies of other systems with nonbounded interactions. To investigate the electrostatic interaction on NH2BHNBHNH2 with six different segments including six loops and six connecting bonds of the B18N18 ring within the vertical transition, first, the five hexagon loops have been freezed, and the electrostatic interaction of NH2BHNBHNH2 with the one remaining active loop has been considered. Other loops have been examined one by one in the same way, and the changes of all of the following calculated quantities have been explored. Next, we were focused on each bond of B18N18 individually and evaluated the interaction of NH2BHNBHNH2 with each of the six connecting bonds of the B18N18 ring and repeated the calculations along each bond. 3.5.1. Analysis of Dipole Moments. The only known mechanisms for the creation of dipole moments are by current loops or quantum mechanical spin since the existence of monopoles has never been experimentally demonstrated.43-45 On the other hand, dipole expansions are used in the study of electromagnetic fields of charge and current distributions. The efficiency of such B37-N38 B37-N38 B37-N41 N38-B39 B39-N40 B39-N40 B37-N38 B37-N38 B37-N41 N38-B39 B39-N40 B39-N40 B37-N38 B37-N38 B37-N41 N38-B39 B39-N40 B39-N40 B37-N38 B37-N38 B37-N41 B37-N41 N38-B39 B39-N40 B39-N40 B37-N38 B37-N38 B37-N41 N38-B39 B39-N40 B39-N40 B37-N38 B37-N38 B37-N41 N38-B39 B39-N40 B39-N40 B37-N38 B37-N38 B37-N41 B37-N41 N38-B39 B39-N40 B39-N40 B37-N38 B37-N38 B37-N41 N38-B39 B39-N40 B39-N40 bond BD(1) BD(2) BD(1) BD(1) BD(1) BD(2) BD(1) BD(2) BD(1) BD(1) BD(1) BD(2) BD(1) BD(2) BD(1) BD(1) BD(1) BD(2) BD(1) BD(2) BD(1) BD(2) BD(1) BD(1) BD(2) BD(1) BD(2) BD(1) BD(1) BD(1) BD(2) BD(1) BD(2) BD(1) BD(1) BD(1) BD(2) BD(1) BD(2) BD(1) BD(2) BD(1) BD(1) BD(2) BD(1) BD(2) BD(1) BD(1) BD(1) BD(2) cation 0.5033*(sp2.23d0.01)B + 0.8641*(sp1.00)N 0.3792*(sp99.99d2.91)B + 0.9253*(sp99.99d0.20f0.30)N 0.5253*(sp1.76)B + 0.8509*(sp1.38)N 0.8641*(sp1.00)N + 0.5033*(sp2.23d0.01)B 0.3795*(sp99.99d1.28)B + 0.9252*(sp99.99d0.08f0.12)N 0.5250*(sp1.77)B + 0.8511*(sp1.39d0.01)N 0.5022*(sp2.23d0.01)B + 0.8648*(sp1.00)N 0.5264*(sp1.74)B + 0.8502*(sp1.39d0.01)N 0.8647*(sp1.00)N + 0.5022*(sp2.23d0.01)B 0.5265*(sp1.74)B + 0.8502*(sp1.39d0.01)N 0.5017*(sp2.24d0.01)B + 0.8650*(sp1.00)N 0.5275*(sp1.73)B + 0.8496*(sp1.41d0.01)N 0.8650*(sp1.00)N + 0.5018*(sp2.24d0.01)B 0.5275*(sp1.73)B + 0.8495*(sp1.41d0.01)N 0.5033*(sp2.23)B + 0.8641*(sp1.00)N 0.3792*(sp1.00)B + 0.9253*(sp99.99d1.34f1.99)N 0.5255*(sp1.75)B + 0.8508*(sp1.38d0.01)N 0.8641*(sp1.00)N + 0.5033*(sp2.22)B 0.3790*(sp1.00)B + 0.9254*(sp1.00)N 0.5022*(sp2.23d0.01)B + 0.8648*(sp1.00)N 0.5265*(sp1.74)B + 0.8502*(sp1.39d0.01)N 0.8647*(sp1.00)N + 0.5022*(sp2.23d0.01)B 0.5265*(sp1.74)B + 0.8501*(sp1.39d0.01)N 0.5018*(sp2.24d0.01)B + 0.8650*(sp1.00)N 0.5271*(sp1.74)B + 0.8498*(sp1.41)N 0.8650*(sp1.00)N + 0.5018*(sp2.24d0.01)B 0.5271*(sp1.74)B + 0.8498*(sp1.41d0.01)N 0.5033*(sp2.23)B + 0.8641*(sp1.00)N 0.3792*(sp99.99d4.91)B + 0.9253*(sp99.99d0.28f0.43)N 0.5254*(sp1.76)B + 0.8509*(sp1.38d0.01)N 0.8641*(sp1.00)N + 0.5033*(sp2.23)B 0.3790*(sp99.99d8.03)B + 0.9254*(sp99.99d0.55f0.84)N 0.5254*(sp1.75)B + 0.8509*(sp1.38d0.01)N 0.5021*(sp2.24d0.01)B + 0.8648*(sp1.00)N 0.5264*(sp1.74)B + 0.8502*(sp1.39d0.01)N 0.8648*(sp1.00)N + 0.5021*(sp2.24d0.01)B 0.5265*(sp1.74)B + 0.8502*(sp1.39d0.01)N - anion 0.5021*(sp2.12)B + 0.8648*(sp1.00)N 0.3275*(sp99.99d7.31)B + 0.9449*(sp1.00)N 0.5008*(sp1.97)B + 0.8656*(sp1.22)N 0.8648*(sp1.00)N + 0.5021*(sp2.12)B 0.5007*(sp2.00)B + 0.8656*(sp1.22)N 0.3549*(sp99.99d0.73)B + 0.9349*(sp99.99d0.03f0.07)N 0.5021*(sp2.12)B + 0.8648*(sp1.00)N 0.3276*(sp99.99d8.71)B + 0.9448*(sp1.00)N 0.5009*(sp1.97)B + 0.8655*(sp1.22d0.01)N 0.8648*(sp1.00)N + 0.5021*(sp2.12)B 0.5008*(sp1.99)B + 0.8656*(sp1.22d0.01)N 0.3542*(sp99.99d0.88)B + 0.9352*(sp99.99d0.03f0.08)N 0.5195*(sp2.10)B + 0.8544*(sp1.00)N 0.3527*(sp1.00)B + 0.9357*(sp1.00)N 0.5181*(sp1.88)B + 0.8553*(sp1.31)N 0.8544*(sp1.00)N + 0.5195*(sp2.10)B 0.3552*(sp99.99d4.50)B + 0.9348*(sp99.99d0.11f0.49)N 0.5180*(sp1.89)B + 0.8554*(sp1.31)N 0.5021*(sp2.12)B + 0.8648*(sp1.00)N 0.3275*(sp1.00)B + 0.9449*(sp1.00)N 0.5015*(sp1.97)B + 0.8652*(sp1.21)N 0.8648*(sp1.00)N + 0.5021*(sp2.12)B 0.5016*(sp1.98)B + 0.8651*(sp1.21)N 0.3544*(sp99.99d2.76)B + 0.9351*(sp99.99d0.11f0.28)N 0.5021*(sp2.12)B + 0.8648*(sp1.00)N 0.3276*(sp99.99d6.55)B + 0.9448*(sp1.00)N 0.5005*(sp1.97)B + 0.8657*(sp1.23d0.01)N 0.8648*(sp1.00)N + 0.5021*(sp2.12)B 0.5004*(sp2.00)B + 0.8658*(sp1.23d0.01)N 0.3548*(sp99.99d0.63)B + 0.9349*(sp99.99d0.02)N 0.5193*(sp2.10)B + 0.8546*(sp1.00)N 0.3522*(sp1.00)B + 0.9359*(sp1.00)N 0.5181*(sp1.88)B + 0.8553*(sp1.30)N 0.8546*(sp1.00)N + 0.5193*(sp2.10)B 0.3547*(sp99.99d11.73)B + 0.9350*(sp99.99d0.27f1.27)N 0.5181*(sp1.88)B + 0.8553*(sp1.31)N 0.5021*(sp2.12)B + 0.8648*(sp1.00)N 0.3275*(sp99.99d27.22)B + 0.9448*(sp1.00)N 0.5013*(sp1.97)B + 0.8652*(sp1.21)N 0.8648*(sp1.00)N + 0.5021*(sp2.12)B 0.5014*(sp1.98)B + 0.8652*(sp1.21)N 0.3543*(sp99.99d1.80)B + 0.9351*(sp99.99d0.07f0.18)N 0.5021*(sp2.13)B + 0.8648*(sp1.00)N 0.3278*(sp99.99d7.98)B + 0.9447*(sp1.00)N 0.5007*(sp1.98)B + 0.8656*(sp1.22)N 0.8648*(sp1.00)N + 0.5021*(sp2.12)B 0.5006*(sp2.00)B + 0.8657*(sp1.22)N 0.3543*(sp99.99d0.78)B + 0.9351*(sp99.99d0.02f0.07)N radical 0.5020*(sp2.13)B + 0.8649*(sp1.00)N 0.3277*(sp99.99d5.16)B + 0.9448*(sp1.00)N 0.5009*(sp1.97)B + 0.8655*(sp1.23)N 0.8649*(sp1.00)N + 0.5020*(sp2.13)B 0.5007*(sp2.01)B + 0.8656*(sp1.23)N 0.3571*(sp99.99d0.52)B + 0.9341*(sp99.99d0.02f0.05)N 0.5020*(sp2.13)B + 0.8649*(sp1.00)N 0.3278*(sp99.99d7.24)B + 0.9448*(sp1.00)N 0.5014*(sp1.97)B + 0.8652*(sp1.23d0.01)N 0.8649*(sp1.00)N + 0.5020*(sp2.13)B 0.5013*(sp1.99)B + 0.8653*(sp1.23d0.01)N 0.3561*(sp99.99d0.76)B + 0.9344*(sp99.99d0.02f0.07)N 0.5019*(sp2.13)B + 0.8649*(sp1.00)N 0.3280*(sp99.99d25.66)B + 0.9447*(sp1.00)N 0.5019*(sp1.97)B + 0.8650*(sp1.23d0.01)N 0.8649*(sp1.00)N + 0.5019*(sp2.13)B 0.5019*(sp1.98)B + 0.8649*(sp1.23d0.01)N 0.3554*(sp99.99d1.56)B + 0.9347*(sp99.99d0.05f0.16)N 0.5020*(sp2.13)B + 0.8649*(sp1.00)N 0.3277*(sp1.00)B + 0.9448*(sp1.00)N 0.5018*(sp1.97)B + 0.8650*(sp1.21)N 0.8648*(sp1.00)N + 0.5020*(sp2.13)B 0.5019*(sp1.98)B + 0.8649*(sp1.21)N 0.3558*(sp99.99d2.18)B + 0.9346*(sp99.99d0.08f0.22)N 0.5020*(sp2.13)B + 0.8649*(sp1.00)N 0.3277*(sp99.99d5.09)B + 0.9448*(sp1.00)N 0.5009*(sp1.97)B + 0.8655*(sp1.24d0.01)N 0.8649*(sp1.00)N + 0.5020*(sp2.13)B 0.5007*(sp2.01)B + 0.8656*(sp1.24d0.01)N 0.3568*(sp99.99d0.51)B + 0.9342*(sp99.99d0.02f0.05)N 0.5019*(sp2.13)B + 0.8650*(sp1.00)N 0.3280*(sp1.00)B + 0.9447*(sp1.00)N 0.5021*(sp1.97)B + 0.8648*(sp1.22d0.01)N 0.8650*(sp1.00)N + 0.5019*(sp2.13)B 0.5022*(sp1.97)B + 0.8648*(sp1.22d0.01)N 0.3550*(sp99.99d3.43)B + 0.9349*(sp99.99d0.09f0.36)N 0.5020*(sp2.13)B + 0.8649*(sp1.00)N 0.3278*(sp99.99d19.81)B + 0.9448*(sp1.00)N 0.5016*(sp1.97)B + 0.8651*(sp1.21)N 0.8649*(sp1.00)N + 0.5020*(sp2.13)B 0.5017*(sp1.98)B + 0.8650*(sp1.21)N 0.3560*(sp99.99d1.41)B + 0.9345*(sp99.99d0.05f0.14)N 0.5020*(sp2.13)B + 0.8649*(sp1.00)N 0.3279*(sp99.99d5.89)B + 0.9447*(sp1.00)N 0.5011*(sp1.97)B + 0.8654*(sp1.23d0.01)N 0.8649*(sp1.00)N + 0.5020*(sp2.13)B 0.5009*(sp2.00)B + 0.8655*(sp1.23d0.01)N 0.3566*(sp99.99d0.59)B + 0.9342*(sp99.99d0.02f0.06)N J. Phys. Chem. C, Vol. 114, No. 36, 2010 0.0,0.0,130.0 0.0,0.0,110.0 0.0,0.0,90.0 0.0,0.0,70.0 0.0,0.0,50.0 0.0,0.0,30.0 0.0,0.0,10.0 0.0,0.0,0.0 orientations NBO analysis TABLE 3: NBO Analysis of the B18N18-NH2BHNBHNH2 System Considering Radical, Cationic, and Anionic Forms of NH2BHNBHNH2 with Different Coordinates at the B3LYP/ EPR-III Level of Theory 15320 Monajjemi et al. radical 0.5019*(sp2.13)B + 0.8650*(sp1.00)N 0.3282*(sp1.00)B + 0.9446*(sp1.00)N 0.5022*(sp1.97)B + 0.8647*(sp1.21)N 0.8649*(sp1.00)N + 0.5019*(sp2.13)B 0.5023*(sp1.97)B + 0.8647*(sp1.21)N 0.3550*(sp99.99d6.18)B + 0.9349*(sp99.99d0.16f0.66)N 0.5019*(sp2.13)B + 0.8649*(sp1.00)N 0.3280*(sp1.00)B + 0.9447*(sp1.00)N 0.5021*(sp1.97)B + 0.8648*(sp1.20)N 0.8649*(sp1.00)N + 0.5019*(sp2.13)B 0.5022*(sp1.97)B + 0.8648*(sp1.20)N 0.3553*(sp99.99d6.06)B + 0.9347*(sp99.99d0.19f0.64)N NH2BHNBHNH2 Inside of the B18N18 Nanoring J. Phys. Chem. C, Vol. 114, No. 36, 2010 15321 a fast method is superior if the system is clustered and has large density fluctuation.44 Therefore, the lack of experimental demonstration and its importance in theoretical simulations was a motivation for us to investigate dipole moments from a theoretical point of view. The coefficients of angular coordinates of multipole moment are defined as a sum of following spherical harmonics ∞ f(θ, φ) ) l ∑ ∑ ClmYlm(θ, φ) (2) l)0 m)-l Therefore, the electromagnetic potential can be obtained as ∞ V ) (r, θ, φ) l ∑ ∑ Clm(r)Ylm(θ, φ) ) 0.5019*(sp2.24d0.01)B + 0.8649*(sp1.00)N 0.5268*(sp1.74)B + 0.8500*(sp1.39d0.01)N 0.8649*(sp1.00)N + 0.5019*(sp2.24d0.01)B 0.5269*(sp1.74)B + 0.8500*(sp1.39d0.01)N 0.5033*(sp2.23d0.01)B + 0.8641*(sp1.00)N 0.3790*(sp99.99d5.73)B + 0.9254*(sp99.99d0.33f0.52)N 0.5253*(sp1.76)B + 0.8509*(sp1.37d0.01)N 0.8641*(sp1.00)N + 0.5033*(sp2.23d0.01)B 0.3788*(sp99.99d15.10)B + 0.9255*(sp99.99d1.09f1.71)N 0.5253*(sp1.75)B + 0.8509*(sp1.37d0.01)N 0.0,0.0,170.0 cation anion 0.5020*(sp2.13)B + 0.8649*(sp1.00)N 0.3280*(sp1.00)B + 0.9447*(sp1.00)N 0.5016*(sp1.97)B + 0.8651*(sp1.21)N 0.8649*(sp1.00)N + 0.5020*(sp2.13)B 0.5016*(sp1.98)B + 0.8651*(sp1.21)N 0.3530*(sp99.99d4.59)B + 0.9356*(sp99.99d0.13f0.50)N 0.5020*(sp2.13)B + 0.8649*(sp1.00)N 0.3277*(sp1.00)B + 0.9448*(sp1.00)N 0.5016*(sp1.97)B + 0.8651*(sp1.20)N 0.8649*(sp1.00)N + 0.5020*(sp2.13)B 0.5016*(sp1.98)B + 0.8651*(sp1.19)N 0.3533*(sp99.99d6.04)B + 0.9355*(sp99.99d0.20f0.64)N B37-N38 B37-N38 B37-N41 N38-B39 B39-N40 B39-N40 B37-N38 B37-N38 B37-N41 B37-N41 N38-B39 B39-N40 B39-N40 BD(1) BD(2) BD(1) BD(1) BD(1) BD(2) BD(1) BD(2) BD(1) BD(2) BD(1) BD(1) BD(2) bond orientations TABLE 3: Continued 0.0,0.0,150.0 NBO analysis i)0 m)-l ∞ ∞ l ∑∑ ∑ m Dl,j j r j)1 l)0 m)-l Ylm(θ, φ) (3) The tailor expansion of V(r - R) around the r ) 0 is V(r - R) ) V(R) - ∑ R)x,y,z raVR(R) + ∑ ∑ 1 2 R)x,y,z rRrβVaβ(R) - ... + ... (4) β)x,y,z where VR(R) ) ( ∂V(r - R) ∂rR ) ( and VRβ(R) ) ∂2V(r - R) ∂rR∂rβ ) r)0 (5) Therefore, the above equation can be considered as the differential of V in terms of r. 3.5.2. Interaction of Two NonoWerlapping Parts of NH2BHNBHNH2 and B18N18. The total electrostatic interaction energy of the considered system (UNH2BHNBHNH2-B18N18) between the two charge distributions of two B18N18 and NH2BHNBHNH2 molecules is UB18N18-NH2BHNBHNH2 ) ∑ µ∈B18N18 qµqV 4πε0rµV V∈NH2BHNBHNH2 (6) ∑ As a consequence of the electrostatic B18N18-NH2BHNBHNH2 interaction, the charge distribution of the NH2BHNBHNH2 molecule inside of the B18N18 ring polarizes the B18N18 charge distribution and induces the electromagnetic field in the B18N18-NH2BHNBHNH2 system. Considering rXY ) rY - rX, it can be defined as RB18N18-NH2BHNBHNH2 + rNH2BHNBHNH2,V + rVµ - rµ,B18N18 ) 0 (7) Since the two distributions do not overlap 0.502 1.873 0.202 2.303 0.217 2.233 0.495 1.885 0.213 2.319 0.207 2.320 0.497 1.911 0.197 2.328 0.192 2.308 0.502 1.876 0.201 2.302 0.217 2.232 0.497 1.885 0.216 2.317 0.210 2.318 0.498 1.910 0.200 2.328 0.196 2.308 0.469 3.769 0.413 3.483 0.413 3.479 0.507 1.858 0.207 2.312 0.220 2.243 0.493 1.902 0.216 2.319 0.211 2.314 0.503 1.905 0.193 2.350 0.188 2.302 0.505 1.857 0.208 2.313 0.220 2.245 0.493 1.902 0.214 2.321 0.209 2.315 0.502 1.908 0.191 2.350 0.185 2.302 0.471 3.771 0.405 3.564 0.405 3.566 N4 N41 0.499 1.899 0.183 2.296 0.195 2.319 0.502 1.859 0.222 2.307 0.216 2.324 0.494 1.914 0.211 2.308 0.206 2.317 0.503 1.894 0.182 2.294 0.194 2.318 0.497 1.853 0.219 2.311 0.213 2.328 0.489 1.920 0.210 2.312 0.205 2.320 1 3.763 0.426 3.384 0.426 3.391 0,0,30 0.503 1.904 0.178 2.302 0.197 2.375 0.509 1.848 0.218 2.276 0.213 2.320 0.490 1.914 0.210 2.312 0.209 2.324 0.502 1.906 0.175 2.302 0.194 2.373 0.510 1.849 0.219 2.274 0.213 2.319 0.491 1.914 0.213 2.311 0.213 2.322 0.472 3.773 0.404 3.578 0.404 3.572 0,0,50 0.493 1.915 0.191 2.313 0.202 2.329 0.505 1.875 0.215 2.230 0.203 2.298 0.496 1.886 0.212 2.320 0.216 2.320 0.501 1.910 0.194 2.309 0.207 2.324 0.511 1.866 0.212 2.228 0.201 2.296 0.490 1.880 0.207 2.325 0.211 2.324 0.468 3.768 0.412 3.489 0.412 3.500 0,0,70 0.493 1.915 0.191 2.313 0.202 2.329 0.505 1.875 0.215 2.230 0.203 2.298 0.496 1.886 0.212 2.320 0.216 2.320 0.501 1.910 0.194 2.309 0.207 2.324 0.511 1.866 0.212 2.228 0.201 2.296 0.490 1.880 0.207 2.325 0.211 2.324 0.468 3.768 0.412 3.489 0.412 3.500 0,0,90 anionic 0.491 1.913 0.213 2.321 0.214 2.309 0.503 1.904 0.202 2.374 0.182 2.300 0.508 1.850 0.214 2.320 0.210 2.286 0.490 1.913 0.210 2.323 0.210 2.310 0.502 1.906 0.199 2.372 0.178 2.300 0.509 1.851 0.214 2.318 0.210 2.285 0.470 3.768 0.404 3.567 0.404 3.562 0,0,110 0.496 1.890 0.212 2.318 0.209 2.319 0.498 1.910 0.205 2.325 0.193 2.307 0.503 1.871 0.207 2.299 0.205 2.248 0.496 1.890 0.215 2.317 0.211 2.318 0.499 1.907 0.206 2.325 0.193 2.307 0.501 1.871 0.208 2.300 0.205 2.249 0.469 3.765 0.407 3.520 0.408 3.521 0,0,130 0.500 1.865 0.213 2.310 0.212 2.323 0.491 1.916 0.215 2.307 0.204 2.318 0.499 1.896 0.191 2.293 0.198 2.320 0.500 1.864 0.213 2.310 0.213 2.323 0.492 1.915 0.214 2.306 0.203 2.318 0.498 1.897 0.191 2.294 0.198 2.321 0.465 3.757 0.414 3.444 0.415 3.441 0,0,150 0.504 1.858 0.205 2.286 0.216 2.315 0.490 1.912 0.212 2.310 0.210 2.321 0.501 1.906 0.183 2.298 0.198 2.371 0.505 1.859 0.206 2.283 0.216 2.313 0.491 1.911 0.214 2.308 0.212 2.320 0.502 1.904 0.186 2.299 0.200 2.371 0.471 3.764 0.402 3.572 0.402 3.575 0,0,170 0.503 1.939 0.261 2.370 0.218 2.354 0.511 1.945 0.236 2.359 0.211 2.377 0.454 1.953 0.281 2.489 0.228 2.432 0.502 1.940 0.262 2.369 0.218 2.356 0.510 1.947 0.240 2.353 0.214 2.372 0.455 1.955 0.282 2.489 0.229 2.428 0.358 8.992 0.061 3.538 0.062 3.537 0,0,0 0.476 1.949 0.269 2.391 0.234 2.374 0.522 1.943 0.238 2.350 0.209 2.381 0.464 1.948 0.251 2.435 0.222 2.416 0.475 1.949 0.269 2.392 0.236 2.375 0.522 1.944 0.240 2.345 0.211 2.377 0.465 1.949 0.252 2.435 0.223 2.412 0.355 9.091 0.024 3.471 0.025 3.471 0,0,10 0.432 1.949 0.285 2.429 0.329 2.507 0.545 1.936 0.207 2.388 0.232 2.368 0.491 1.927 0.214 2.413 0.196 2.435 0.431 1.947 0.288 2.431 0.334 2.505 0.547 1.935 0.207 2.387 0.228 2.373 0.489 1.929 0.216 2.412 0.198 2.433 0.353 9.463 0.030 3.424 0.029 3.421 0,0,30 0.443 1.961 0.234 2.428 0.325 2.542 0.524 1.934 0.219 2.357 0.257 2.365 0.501 1.948 0.219 2.368 0.228 2.372 0.442 1.960 0.234 2.429 0.324 2.545 0.523 1.936 0.217 2.360 0.260 2.362 0.500 1.950 0.221 2.363 0.232 2.365 0.358 9.013 0.065 3.564 0.065 3.561 0,0,50 0.443 1.961 0.234 2.428 0.325 2.542 0.524 1.934 0.219 2.357 0.257 2.365 0.501 1.948 0.219 2.368 0.228 2.372 0.442 1.960 0.234 2.429 0.324 2.545 0.523 1.936 0.217 2.360 0.260 2.362 0.500 1.950 0.221 2.363 0.232 2.365 0.358 9.013 0.065 3.564 0.065 3.561 0,0,70 0.490 1.945 0.216 2.394 0.233 2.367 0.434 1.958 0.304 2.491 0.267 2.408 0.530 1.945 0.250 2.357 0.211 2.396 0.490 1.937 0.221 2.386 0.225 2.372 0.438 1.947 0.308 2.469 0.261 2.431 0.534 1.940 0.240 2.370 0.224 2.378 0.357 9.137 0.013 3.373 0.010 3.382 0,0,90 cationic 0.501 1.950 0.231 2.363 0.224 2.359 0.444 1.962 0.322 2.536 0.234 2.431 0.520 1.936 0.255 2.384 0.218 2.371 0.501 1.949 0.230 2.364 0.225 2.359 0.444 1.962 0.322 2.537 0.235 2.431 0.520 1.936 0.255 2.380 0.217 2.373 0.356 8.995 0.062 3.550 0.063 3.547 0,0,110 0.524 1.943 0.234 2.344 0.222 2.369 0.464 1.954 0.259 2.431 0.224 2.406 0.474 1.948 0.277 2.430 0.237 2.383 0.524 1.944 0.234 2.344 0.220 2.372 0.464 1.953 0.260 2.427 0.221 2.411 0.474 1.946 0.276 2.433 0.239 2.380 0.355 9.089 0.041 3.502 0.042 3.499 0,0,130 0.524 1.943 0.234 2.344 0.222 2.369 0.464 1.954 0.259 2.431 0.224 2.406 0.474 1.948 0.277 2.430 0.237 2.383 0.524 1.944 0.234 2.344 0.220 2.372 0.464 1.953 0.260 2.427 0.221 2.411 0.474 1.946 0.276 2.433 0.239 2.380 0.355 9.089 0.041 3.502 0.042 3.499 0,0,150 0.512 1.942 0.220 2.379 0.251 2.395 0.502 1.951 0.222 2.366 0.230 2.365 0.444 1.961 0.236 2.454 0.309 2.528 0.512 1.941 0.221 2.376 0.251 2.398 0.503 1.950 0.223 2.364 0.229 2.365 0.445 1.961 0.237 2.452 0.308 2.527 0.356 8.959 0.068 3.541 0.068 3.539 0,0,170 J. Phys. Chem. C, Vol. 114, No. 36, 2010 N40 N38 N36 N34 N32 N31 N29 N28 N25 N22 N20 N19 N17 N16 N13 N10 N8 N7 N5 0,0,10 0,0,0 atoms χ (MHz) η TABLE 4: NQR Parameters of Nitrogen Atoms of B18N18-NH2BHNBHNH2 in the Anionic, Cationic, and Radical Forms at the B3LYP/EPR-III Level of Theory 15322 Monajjemi et al. 0.476 1.973 0.269 2.350 0.234 2.284 0.522 1.976 0.238 2.353 0.209 2.356 0.464 1.988 0.251 2.382 0.222 2.358 0.475 1.973 0.269 2.350 0.236 2.284 0.522 1.975 0.240 2.352 0.211 2.356 0.465 1.988 0.252 2.383 0.223 2.358 0.355 3.760 0.024 3.429 0.025 3.429 0.498 1.965 0.258 2.350 0.276 2.283 0.490 1.975 0.254 2.358 0.251 2.354 0.471 1.988 0.258 2.415 0.243 2.360 0.498 1.965 0.258 2.350 0.276 2.283 0.490 1.975 0.254 2.358 0.252 2.354 0.471 1.988 0.258 2.416 0.243 2.360 0.463 3.762 0.394 3.532 0.394 3.531 N4 N41 N40 N38 N36 N34 N32 N31 N29 N28 N25 N22 N20 N19 N17 N16 N13 N10 N8 N7 N5 0,0,10 0,0,0 atoms TABLE 4: Continued 0.432 1.968 0.285 2.318 0.329 2.348 0.545 1.979 0.207 2.350 0.232 2.360 0.491 1.990 0.214 2.358 0.196 2.441 0.431 1.968 0.288 2.317 0.334 2.348 0.547 1.979 0.207 2.350 0.228 2.360 0.489 1.990 0.216 2.358 0.198 2.440 0.353 3.761 0.030 3.540 0.029 3.539 0,0,30 0.462 1.989 0.237 2.364 0.265 2.446 0.510 1.960 0.267 2.306 0.258 2.352 0.485 1.979 0.252 2.352 0.248 2.362 0.463 1.989 0.237 2.364 0.266 2.445 0.510 1.960 0.267 2.306 0.258 2.352 0.485 1.979 0.252 2.352 0.248 2.361 0.464 3.766 0.392 3.558 0.393 3.556 0,0,50 0.474 1.988 0.244 2.360 0.263 2.380 0.485 1.968 0.276 2.284 0.258 2.348 0.495 1.976 0.250 2.357 0.253 2.354 0.474 1.987 0.244 2.360 0.263 2.379 0.485 1.968 0.276 2.284 0.258 2.348 0.496 1.976 0.251 2.357 0.253 2.354 0.460 3.760 0.396 3.447 0.397 3.447 0,0,70 0.481 1.984 0.244 2.362 0.257 2.351 0.460 1.986 0.268 2.380 0.250 2.354 0.508 1.968 0.253 2.357 0.257 2.340 0.481 1.984 0.244 2.362 0.257 2.350 0.460 1.986 0.268 2.380 0.250 2.354 0.508 1.968 0.253 2.357 0.257 2.340 0.456 3.754 0.404 3.341 0.404 3.342 0,0,90 radical 0.485 1.978 0.249 2.361 0.253 2.351 0.462 1.990 0.270 2.445 0.241 2.361 0.510 1.962 0.260 2.351 0.258 2.316 0.485 1.978 0.248 2.361 0.253 2.351 0.463 1.989 0.270 2.445 0.241 2.361 0.510 1.962 0.260 2.351 0.258 2.316 0.463 3.762 0.393 3.543 0.393 3.542 0,0,110 0.495 1.973 0.254 2.353 0.252 2.356 0.474 1.986 0.263 2.383 0.244 2.360 0.484 1.973 0.263 2.343 0.268 2.296 0.495 1.973 0.254 2.353 0.252 2.357 0.475 1.986 0.264 2.382 0.244 2.360 0.484 1.973 0.263 2.343 0.267 2.296 0.460 3.756 0.394 3.473 0.394 3.472 0,0,130 χ (MHz) η 0.505 1.970 0.255 2.340 0.255 2.356 0.480 1.986 0.259 2.351 0.246 2.361 0.463 1.987 0.254 2.351 0.265 2.386 0.505 1.970 0.255 2.340 0.255 2.356 0.480 1.985 0.259 2.351 0.246 2.361 0.463 1.987 0.253 2.351 0.265 2.386 0.457 3.754 0.397 3.390 0.397 3.388 0,0,150 0.504 1.968 0.254 2.318 0.263 2.348 0.485 1.979 0.254 2.350 0.249 2.360 0.464 1.990 0.244 2.358 0.266 2.441 0.504 1.968 0.254 2.317 0.264 2.348 0.485 1.979 0.254 2.350 0.249 2.360 0.464 1.990 0.244 2.358 0.266 2.440 0.463 3.761 0.392 3.540 0.392 3.539 0,0,170 NH2BHNBHNH2 Inside of the B18N18 Nanoring J. Phys. Chem. C, Vol. 114, No. 36, 2010 15323 15324 J. Phys. Chem. C, Vol. 114, No. 36, 2010 Monajjemi et al. |RB18N18-NH2BHNBHNH2 | > |rB18BHNBHNH2,V - rB18N18,µ | (8) The Laplace expansion could be considered as 1 ) |rV - rµ | 1 ) |RB18N18-NH2BHNBHNH2 - (rB18N18,µ - rNH2BHNBHNH2,V)| ∞ L ∑ ∑ L)0 M)-L (-1)MIL-M(RB18N18-NH2BHNBHNH2) × RLM(rB18N18,µ (9) - rNH2BHNBHNH2,V) whereILM and RLM are irregular and regular solid harmonics, respectively. The dipole moment can be measured by a variety of experimental methods or computed with an atomic charge distribution directly derived from molecular orbital calculations, as well as the interaction energy of two B18N18 and NH2BHNBHNH2 charge distributions at a distance of RB18N18-NH2BHNBHNH2 apart. Since B18N18+mNH2BHNBHNH2) Il-(m (RB18N18-NH2BHNBHNH2) ) B N +lNH BHNBHNH 18 18 2 [ 2 4π 2lB18N18 + 2lNH2BHNBHNH2 + 1 ] 1/2 × B18N18+mNH2BHNBHNH2) Yl-(m (R̂B18N18-NH2BHNBHNH2) B N +lNH BHNBHNH 18 18 2 2 NH2BHNBHNH2+1 RBlB1818NN1818+l -NH2BHNBHNH2 (10) A dipole moment which appears to be due to an electric charge distribution usually involves powers (or inverse powers) of the distance to the origin (r) as well as some angular dependence (Θ and Φ), where Θ is the angle with the x and y axes and Φ is the angle with the vertical axis inside of the ring.44,45 The dipole moment converges under two conditions, (1) if the charges are localized close to the origin and the point at which the potential is observed is far from the origin where the coefficients of the series expansion are called exterior dipole moments or simply dipole moments and (2) if the charges are located far from the origin and the potential is observed close to the origin, namely, interior dipole moments. The importance of this quantity is embedded in the fact that the potential at a position within a charge distribution can often be computed by combining interior and exterior dipoles.43-45 When a single NH2BHNBHNH2 molecule is just supposed, the Θ ) Φ ) 0, that is, the dipole vector, is expected to be coincident on the NH2BHNBHNH2 axis. According to obtained dipole moments, it can be distinguished that the r component of the dipole moment vector of each the radical, cationic, and anionic forms of NH2BHNBHNH2 involved in the ring had the tendency to rotate in three different cone surfaces. Therefore, it could be realized that our observed dipole moment has been directed linearly, and this observation supported the intrinsic linear form of the NH2BHNBHNH2 molecule. In this regard, it seems that if a biomolecule is being set in the B18N18-NH2BHNBHNH2 system due to generation of radical, anion, and cation forms of NH2BHNBHNH2, the electrical current will cross along the ring that changes all calculated atomic physicochemical properties. Here, it is notable that the three emerged radical, cationic, and anionic forms of NH2BHNBHNH2 generate frequently to each other, and if these three species are imagined in the three quantized cone surfaces, it can be deduced that the variation of the radial vector of system’s dipole moment (r) would be quantized within crossing of these three cone levels. An induced dipole of any polarizable charge distribution F of the NH2BHNBHNH2 molecule has been caused by an electric field external to F that originated from an ion or polar molecule in the vicinity of F .The strength of the induced dipole is equal to the product of the strength of the external field and the dipole polarizibility of F. Therefore, along with the variation of the radial component (r), the two other remaining components of the dipole moment, namely, Θ and Φ, will be changed and cause the quantized rotation of the NH2BHNBHNH2 molecule due to the electrical charge of NH2BHNBHNH2. Its induced electrostatic interaction on the ring will be affected, and the rotation of the B18N18 ring will also be expected to be quantized. On the other hand, for a dipole moment (m), the energy of the dipole interaction (U) is defined as43-45 U ) -m · B (11) Supposing eq 11, the logical variation of the dipole moment at different rotational angles of the NH2BHNBHNH2 radical was satisfactory. The average value of the dipole moment vector (r) for anion, cation, and radical forms of NH2BHNBHNH2 has been obtained as 10.842, 5.258, and 3.302 D, respectively. Along with the high values of Θ and Φ, the r of the dipole moment holds a Gaussian distribution; this fact can be observed in the plotted Gaussian graphs of the dipole moment (r) versus the Θ and Φ angles (Figure 3). Here, it is interesting that for each radical, cation, and anion of NH2BHNBHNH2, three individual expectation values of 〈∆E〉, 〈∆V〉, and 〈∆r〉 have been obtained, and as a whole, it seems that the r component of the system’s dipole moment, voltage differences, and relative energies is quantized, and the system undergoes quantization through rotation. 3.6. Electromagnetic Hyperfine Parameters. In this section, the major point is embedded in the investigation of the electrostatic interaction of NH2BHNBHNH2 with its surrounding B18N18 ring, which forms the basis for more detailed studies of other systems with nonbounded interactions. Total atomic charges, spin densities, electric potential, and isotropic Fermi coupling constants of cationic and anionic forms of NH2BHNBHNH2 in different loops and bonds of the B18N18 system are reported in Table 5. The expectation values of the quantized radical coordinate of the dipole moment, voltage differences (au), and relative energies of B18N18-NH2BHNBHNH2 systems are displayed in Figure 3. Also, the relative energies (∆E), radial coordinate of the dipole moment (r), as well as the voltage differences (∆V) and transition of the B18N18-NH2BHNBHNH2 and B18N18-AlaNH2BHNBHNH2-Gly systems are given in Tables 6 and 7, respectively. The voltage differences of the anionic form of the NH2BHNBHNH2 molecule for each bond were scattered compared with those of the NH2BHNBHNH2 cationic and radical forms and yielded the highest values (78.62-183.41 au). In the case of the cationic form of NH2BHNBHNH2, the bonding ∆V values were close together and were between those of anionic and radical forms (70.90-82.91 au). NH2BHNBHNH2 Inside of the B18N18 Nanoring J. Phys. Chem. C, Vol. 114, No. 36, 2010 15325 Figure 3. The Gaussian distributions and expectation values of the quantized radical coordinate of the dipole moment, voltage differences (au) and relative energies of B18N18-NH2BHNBHNH2 systems at the B3LYP/EPR-III level of theory. The bonding ∆V of the NH2BHNBHNH2 radical was lower than those of the anionic and cationic forms, and the negative values have been found for bond 6 and bond 3 (-8.77 and -72.24 au). The graphs of ∆V values of the anion, cation, and radical versus θ are exhibited in Figure 4. In each case, linear relationships have been found between ∆V and θ values. An approximate coincidence has been observed between the cationic and radical forms, and it is notable that at θ ) 88.32 and 95.15, which correspond to the negative bonding voltages (∆V ) -8.77 and 12.24 au, respectively), the two figures crossed each other. However, in the case of the NH2BHNBHNH2 anion, the variation of θ had no effect on the bonding ∆V for the cation’s two broadened picks (at θ ) 90.79 and ∆V ) 76.79 au) and for the radical’s single broad Gaussian curve (at θ ) 0.99 and ∆V ) 148.05). A similar trend with a minimum pick could be observed for the NH2BHNBHNH2 radical and cationic forms, and conversely, the maximum belonged to the NH2BHNBHNH2 anion. The graphs of the isotropic Fermi constants versus the spin densities in each loop of the B18N18-NH2BHNBHNH2 system are exhibited in Figure 5a and b. The two distinct trends among the various loops of the B18N18-NH2BHNBHNH2 anion could be observed. In more detail, dished and bulged points could be distinguished for even and odd loops, respectively. B(1) B(2) N(4) N(34) B(35) N(36) B(3) N(4) B(3) N(5) B(6) N(7) N(8) B(9) N(8) B(11) N(10) B(11) B(12) N(13) B(14) N(16) B(15) N(16) B(15) N(17) B(18) N(19) N(20) B(21) N(20) B(23) N(22) B(23) B(24) N(25) B(26) N(28) B(27) N(28) B(27) N(29) B(30) N(31) N(32) B(33) N(32) B(35) 0.675284 0.591562 -0.89845 -0.98373 0.695921 -1.02612 0.071167 -0.92833 0.690514 -1.00033 0.730436 -1.12252 -0.90231 0.656619 -0.95917 0.195710 -1.04827 0.694175 0.688249 -1.06352 0.675016 -0.90220 0.091168 -0.90299 0.695482 -0.98443 0.675554 -1.02635 -0.89783 0.591673 -0.93487 0.079622 -1.00051 0.690371 0.730313 -1.12344 0.657002 -0.90102 0.104765 -0.89361 0.694157 -1.04696 0.688494 -1.06391 -0.90326 0.675468 -0.88202 0.093133 total atomic charges 0.087011 0.109841 -0.02246 0.138450 0.530512 0.146993 0.595556 0.529990 0.557910 0.128953 0.078658 0.146106 -0.01073 0.093774 0.834190 0.389747 0.182759 0.520889 0.075684 0.180201 0.077424 -0.03989 0.813937 0.366837 0.530718 0.139249 0.086817 0.147012 -0.02278 0.109707 0.624585 0.498282 0.129061 0.557756 0.078699 0.146824 0.093860 -0.01166 0.756039 0.452083 0.520844 0.181703 0.075560 0.180575 -0.03906 0.077323 0.470138 0.734027 -11.6155 -11.6164 -18.5947 -18.6168 -11.5953 -18.6171 -11.6261 -18.6167 -11.5945 -18.6170 -11.6136 -18.6150 -18.5958 -11.6152 -18.5751 -11.5970 -18.6240 -11.6032 -11.6211 -18.6237 -11.6215 -18.6018 -11.6189 -18.6071 -11.5952 -18.6168 -11.6154 -18.6170 -18.5946 -11.6164 -18.6150 -11.6266 -18.6170 -11.5946 -11.6136 -18.6150 -11.6152 -18.5958 -11.6176 -18.5850 -11.6034 -18.6242 -11.6212 -18.6239 -18.6019 -11.6216 -18.5885 -11.6160 82.70281 81.19617 16.06927 50.92149 279.8979 49.02775 143.2242 -4.95392 275.1061 48.08880 77.92125 48.91770 13.49543 77.78502 2.86549 89.36184 49.39768 274.2737 78.46085 49.18305 78.54765 14.45283 191.4932 -8.36072 279.8553 50.89899 82.66915 49.03377 16.05581 81.16706 -2.44963 128.2253 48.08775 275.0559 77.92315 48.91758 77.79908 13.49334 174.5651 -7.01310 274.2811 49.39048 78.46328 49.17238 14.45320 78.55123 -6.91405 166.3131 electric isotropic Fermi potential coupling MHz ∆V ) V2 - V1 total atomic charges 0.99 156.18 0.99 125.27 0.99 95.96 0.99 64.99 0.99 37.38 0.99 6.35 0.99 24.25 0.99 54.71 0.99 80.59 0.99 115.07 0.99 143.73 0.99 173.71 φ 145.79 131.68 165.93 148.05 78.62 183.41 0.725051 0.677126 -0.70608 -0.71460 0.860079 -0.71373 0.530478 -0.34314 0.849106 -0.74044 0.785697 -0.82325 -0.71234 0.745644 -0.30546 0.593936 -0.73598 0.851300 0.755150 -0.74603 0.747836 -0.67543 0.525317 -0.32706 0.860698 -0.71431 0.725552 -0.71364 -0.70382 0.677482 -0.33832 0.520910 -0.73996 0.848913 0.785423 -0.82326 0.745692 -0.71286 0.562499 -0.35556 0.861636 -0.72340 0.761249 -0.72938 -0.64668 0.756490 -0.28129 0.599537 - -11.2592 -11.2593 -18.2721 -18.2563 -11.1753 -18.2417 -11.1522 -18.1693 -11.1789 -18.2528 -11.2643 -18.2485 -18.2928 -11.2664 -18.1058 -11.1302 -18.2611 -11.1799 -11.2597 -18.2671 -11.2601 -18.2460 -11.1600 -18.1688 -11.1746 -18.2557 -11.2584 -18.2411 -18.2700 -11.2584 -18.1658 -11.1564 -18.2525 -11.1790 -11.2644 -18.2483 -11.2666 -18.2934 -11.1594 -18.1566 -11.1662 -18.2449 -11.2442 -18.2473 -18.2201 -11.2445 88.72 2.79 89.43 62.10 90.18 48.67 90.30 141.79 93.10 104.45 93.40 156.41 90.79 170.50 90.80 111.32 90.46 124.13 89.51 38.98 86.81 76.07 86.63 24.23 φ θ θ total isotropic atomic Fermi spin electric coupling densities potential MHz dipole orientation cation dipole orientation 82.91 70.90 75.11 76.79 78.01 73.97 ∆V ) V2 V1 0.737816 0.684236 -0.73264 -0.76079 0.850185 -0.77635 0.563853 -0.57495 0.855647 -0.77442 0.784624 -0.87397 -0.72616 0.739976 -0.51690 0.518013 -0.77216 0.835288 0.745643 -0.78105 0.740220 -0.75089 -0.47333 -1.46360 0.849841 -0.76056 0.738039 -0.77664 -0.73258 0.684131 -0.60438 0.538637 -0.77442 0.855627 0.784467 -0.87399 0.740291 -0.72597 0.517304 -0.51677 0.835479 -0.77218 0.745799 -0.78116 -0.75136 0.740700 -1.44748 -0.54586 total atomic charges 0.000109 0.000227 0.000013 0.002103 -0.00091 0.000010 -0.07237 0.056951 -0.00016 -0.00046 -0.00088 0.002307 -0.00001 0.000664 -0.15202 0.152977 0.000160 -0.00077 -0.00092 0.000223 -0.00084 0.000921 -0.03485 -0.02805 -0.00087 0.002112 0.000077 0.000045 0.000036 0.000198 0.040675 -0.09240 -0.00046 -0.00015 -0.00090 0.002309 0.000662 -0.00005 0.153492 -0.15241 -0.00083 0.000149 -0.00096 0.000235 0.000977 -0.00088 -0.01138 0.004108 total atomic spin densities -11.3898 -11.3911 -18.3875 -18.4059 -11.3118 -18.4040 -11.2783 -18.3886 -11.3107 -18.4021 -11.3897 -18.4048 -18.3896 -11.3903 -18.3357 -11.2997 -18.4092 -11.3170 -11.3956 -18.4095 -11.3956 -18.3941 -12.0626 -19.3815 -11.3117 -18.4059 -11.3898 -18.4039 -18.3875 -11.3911 -18.4230 -11.3021 -18.4022 -11.3107 -11.3897 -18.4048 -11.3903 -18.3896 -11.3005 -18.3362 -11.3171 -18.4094 -11.3957 -18.4096 -18.3942 -11.3958 -19.3868 -12.1017 -0.02108 -0.04224 0.01514 0.16408 -0.24277 -0.02153 -63.0528 3.58130 -0.35774 -0.04320 0.00752 0.25368 -0.03083 -0.07111 -10.2540 156.7020 0.00450 -0.14478 -0.01670 -0.04216 0.00792 -0.01188 -11.3461 -1.08112 -0.24631 0.15719 -0.02223 -0.01368 0.01571 -0.04268 2.69101 -68.1557 -0.04749 -0.35715 0.00799 0.25980 -0.07093 -0.03105 156.9968 -10.1730 -0.14620 0.00258 -0.01819 -0.04513 -0.01150 0.00741 -1.11873 8.76202 isotropic electric Fermi coupling potential MHz radical 88.32 160.46 89.72 157.65 88.40 26.47 97.19 150.32 95.22 23.62 95.75 87.45 95.15 17.51 90.43 23.56 91.75 154.58 82.88 29.17 82.58 139.04 84.29 124.15 φ θ dipole ordination -8.77 57.32 51.46 -12.24 57.28 51.98 ∆V ) V2 V1 J. Phys. Chem. C, Vol. 114, No. 36, 2010 bond 6 loop 6 bond 5 loop 5 bond 4 loop 4 bond 3 loop 3 bond 2 loop 2 bond 1 loop 1 B18N18 NH2BHNBHNH2 total atomic spin densities anion TABLE 5: Total Atomic Charges, Spin Densities, Electric Potential, and Isotropic Fermi Coupling Constants of Cationic, Anionic, and Radical Forms of NH2BHNBHNH2 in Different Loops and Bonds of the B18N18- NH2BHNBHNH2 System with the EPR-III Basis Set 15326 Monajjemi et al. 3.5806 2.9537 40.0817 3.8248 2.9454 39.9291 Radical 3,4-NH2BHNBHNH2 8,11-NH2BHNBHNH2 15,16-NH2BHNBHNH2 20,23-NH2BHNBHNH2 27,28-NH2BHNBHNH2 32,35-NH2BHNBHNH2 73.97205049 78.01360121 76.79666404 75.11142022 70.90336144 82.9184318 183.4181297 78.62189996 148.051523 165.9353767 131.689849 145.7998385 ∆V 4.7405 6.2301 7.4082 5.3907 7.5771 6.9203 16.6847 16.2562 16.6709 17.4159 15.738 14.736 -296.8050257 -296.7959073 -296.797529 -296.8034243 -296.7950223 -296.7947496 -297.3011035 -297.2936626 -297.290901 -297.3004458 -297.2918986 -297.2802135 ∆E ∆V -297.1875912 -297.1979642 -297.1277353 -297.1870679 -297.1517731 -297.1277108 ∆E ∆V 72.32344707 65.13896048 47.34353246 71.83137729 49.45362824 48.8526457 0.0,0.0,30.0 2.1383 2.777 2.2536 1.8909 2.2835 15.868 r ∆V r 1.9242 2.1117 20.3486 4.7775 3.3971 20.3695 ∆E 0.0,0.0130.0 -297.1875912 -297.1977986 -296.9256791 -297.1269522 -297.1444916 -296.9240049 ∆V 72.32344707 65.54155464 58.08217054 42.387377 52.22628573 58.59084503 r 2.2429 3.0891 2.3907 5.1867 2.9732 2.5548 ∆E 0.0,0.0150.0 -297.1450826 -297.1462957 -297.147889 -297.1244024 -297.1482337 -297.161963 -296.8038289 -296.807387 -296.8037056 -296.7610122 -296.7823038 -296.803554 -297.1474922 -297.1489281 -297.1495568 -297.1879735 -297.1503905 -296.9907382 ∆E 68.35679026 57.8263628 52.09335543 70.13849244 58.54643388 60.41087509 73.51607556 84.04250436 73.01431413 -296.802514 -296.7962275 -296.8046914 -297.1726014 -297.1541433 -297.1415442 -297.1760215 -297.1550241 -297.1567218 71.97336897 48.92890526 -296.803642 -296.7676678 -297.1702861 -297.1784423 -297.1911411 -297.1708904 -297.1786703 -297.1532399 -296.8017205 -296.8032711 -296.8052086 -296.7956764 -296.8031459 -296.8038468 Expectation Values 2.3374 1.7027 2.0341 2.3013 1.6931 2.3872 6.456 4.6703 4.796 8.0526 4.3875 4.9813 ∆V 5.2756 6.3592 6.1544 5.7624 5.8356 6.6779 2.4593 14.0059 20.8958 2.2822 15.2442 20.9007 r 20.9704 7.1532 2.6492 20.7221 4.8733 2.6715 7.0468 5.187 8.2456 4.6699 5.0065 6.1772 16.1405 2.6757 2.9831 15.8837 3.8413 1.7474 r ∆V -296.8040474 -296.8001824 -296.7966976 -296.8015843 -296.8024018 -296.7894125 -297.1549528 -297.018061 -296.9441091 -297.1487567 -296.996191 -296.9399447 ∆E 0.0,0.0170.0 -296.9371613 -297.1176102 -297.1665714 -296.9512951 -297.1324423 -297.166202 -296.7958404 -296.8036949 -296.7813171 -296.8035966 -296.8043561 -296.7957145 73.74027904 77.61282593 84.56040114 74.96797687 73.75105752 89.30435916 60.7514843 35.429805 77.43602829 70.66747623 35.57209468 76.99326403 ∆V 75.65692711 40.28868267 59.37449087 74.96052491 41.17942609 58.89083873 86.79411624 74.77131846 88.72476631 73.33083002 76.23866152 72.24042018 -297.0409236 -58.17047422 -297.1570842 63.62028381 -297.154413 55.044642 -297.0459962 -67.00710058 -297.1490317 65.83730602 -297.1783253 68.64014268 ∆E 0.0,0.0,70.0 62.83373298 2.4598 -297.1492541 59.13620372 2.4707 -297.1563446 60.75084961 70.14386203 5.614 -297.1142335 37.34912396 2.8901 -297.1562986 58.00286999 72.37388193 42.0227 -296.2197214 -22.38555944 42.1078 -296.1765601 -27.92069574 63.53973678 3.0308 -297.1461258 55.30022789 3.519 -297.1426821 53.30695143 70.07053118 5.6166 -297.1143962 37.25622377 2.887 -297.1561308 57.96220763 62.85021458 42.5942 -296.2104798 -15.71696066 38.4851 -296.2870601 -43.31491394 75.63219803 5.1701 -296.8060198 67.56358837 73.27719339 25.8853 -296.3983032 -30.77592463 76.20112339 5.1912 -296.8013138 79.9498708 87.35570152 6.9389 -296.7939101 76.3099308 69.90327296 4.5586 -296.8038023 68.66707051 77.53129068 4.9186 -296.8005993 78.72639013 60.35677766 47.12537767 58.94451464 39.23730295 56.65773872 57.0762871 ∆V 63.62420113 57.59232279 60.8797449 39.7132071 58.24810879 61.06999512 75.88571607 71.52631217 67.90773977 47.14508532 50.38895636 66.4678763 64.60133812 60.93193854 61.86538644 71.93795616 69.56791474 37.69673537 0.0,0.0,50.0 -297.0025552 32.39551179 9.4995 -297.110477 48.07805648 2.3158 -297.1506274 -296.8153581 -276.4829909 2.0027 -297.1959388 67.98781537 6.6596 -297.1308942 -297.1482892 64.26236827 12.9243 -297.0992434 135.6071855 2.8734 -297.1551363 -297.0096335 30.89087891 10.0484 -297.1042342 48.36342398 5.1745 -297.1295553 -296.2654734 -9.953363119 1.9827 -297.1957241 67.99681967 13.2866 -297.0723132 -297.1552991 60.37678398 2.3703 -297.1534902 62.80676482 3.0128 -297.153698 ∆E 0.0,0.0,110.0 1.9242 2.1376 7.1652 1.9075 4.5738 7.4477 r 76.10088034 5.0226 -296.800844 79.82303135 4.3851 72.2204997 5.9668 -296.7990902 72.95049491 4.6953 89.40983079 11.2603 -296.7763455 172.1375715 4.6808 75.77623471 3.9444 -296.8037652 74.12505376 4.3045 82.11742053 5.3894 -296.8045112 68.96993479 3.8949 77.97468385 6.9677 -296.7963587 85.92898481 4.4462 243.1076945 118.8282092 102.5799102 164.3267807 80.78881521 73.43455808 0.0,0.0,10.0 〈r〉 ) 10.84223413 (Debye), 〈∆E〉 ) -297.0637411 (Hartree), 〈∆V〉 ) 61.51723858 (au) 〈r〉 ) 5.258401161 (Debye), 〈∆E〉 ) -296.7915971 (Hartree), 〈∆V〉 ) 70.97727363 (au) 〈r〉 ) 3.302491855 (Debye), 〈∆E〉 ) -296.7176833 (Hartree), 〈∆V〉 ) 55.24589482 (au) νr-c ) 486948.498 GHz, νa-c ) 1792900.812 GHz, νr-a ) 2507076.816 GHz 1.8915 2.7614 3.6452 1.7376 2.6768 2.4845 Radical 3,4-NH2BHNBHNH2 2.2631 -297.1913582 66.8362876 8,11-NH2BHNBHNH2 5.6415 -297.1153161 37.30608467 15,16-NH2BHNBHNH2 19.4425 -296.9611761 80.35437573 20,23-NH2BHNBHNH2 2.3362 -297.1470172 61.42955212 27,28-NH2BHNBHNH2 6.2378 -297.1146633 39.43972611 32,35-NH2BHNBHNH2 20.9495 -296.9150134 169.9426868 anion cation radcal 5.5134 4.0205 5.0334 5.7488 5.9348 5.2324 -296.7798467 114.1707175 -296.8036527 73.83518335 -296.7959193 74.83415426 -296.8014382 76.44540798 -296.800476 79.86470916 -296.8049135 68.7983481 r Cation 3,4-NH2BHNBHNH2 8,11-NH2BHNBHNH2 15,16-NH2BHNBHNH2 20,23-NH2BHNBHNH2 27,28-NH2BHNBHNH2 32,35-NH2BHNBHNH2 ∆V 13.9565 26.2414 5.0326 12.8136 40.5363 2.4729 ∆E Anion 3,4-NH2BHNBHNH2 12.9769 -297.0627642 44.61822651 2.0029 -297.1889383 71.50579434 8,11-NH2BHNBHNH2 15,16-NH2BHNBHNH2 20.7711 -296.9585247 249.2417773 20,23-NH2BHNBHNH2 2.2257 -297.1494632 62.45019908 27,28-NH2BHNBHNH2 2.0705 -297.1881211 69.48339394 32,35-NH2BHNBHNH2 22.012 -296.9228108 618.7871587 9.4218 3.8956 6.3126 5.7933 5.0741 5.3348 r -297.15112 51.98515419 2.3914 -297.1530876 63.49325747 -297.1524553 57.28597702 2.4235 -297.1475956 59.82793766 -296.3332429 -12.24219803 40.0044 -296.2839468 -7.864325557 -297.1506857 51.46525481 14.724 -297.0677137 138.4187253 -297.1526004 57.32731152 2.9955 -297.1534705 56.25370184 -296.2671761 -8.776486474 40.0227 -296.2840582 -8.178705774 -296.8056319 -296.8016614 -296.8001619 -296.8056343 -296.8031029 -296.7919488 -297.3017142 -297.2893226 -297.290822 -297.3011118 -297.291813 -297.2923238 ∆E 0.0,0.0,0.0 0.0,0.0,90.0 5.054 6.9205 5.333 4.9366 5.4775 7.2961 Cation 3,4-NH2BHNBHNH2 8,11-NH2BHNBHNH2 15,16-NH2BHNBHNH2 20,23-NH2BHNBHNH2 27,28-NH2BHNBHNH2 32,35-NH2BHNBHNH2 r 16.5939 15.1347 15.7928 16.8942 15.4523 15.3515 r Anion 3,4-NH2BHNBHNH2 8,11-NH2BHNBHNH2 15,16-NH2BHNBHNH2 20,23-NH2BHNBHNH2 27,28-NH2BHNBHNH2 32,35-NH2BHNBHNH2 B18N18-NH2BHNBHNH2 TABLE 6: Part of the Quantitative Expectation Values of Data Including Relative Energies (∆E), the Radial Coordinate of the Dipole Moment (r), As Well As the Voltage Differences (∆V) and Transition of the B18N18-NH2BHNBHNH2 System NH2BHNBHNH2 Inside of the B18N18 Nanoring J. Phys. Chem. C, Vol. 114, No. 36, 2010 15327 -68.52583119 -61.80784132 -70.9732831 25.26434969 - - - - - - -903.1897052 -903.1839202 -903.1863449 -903.0327035 -1062.692251 -1062.685977 -1062.691185 -1062.691814 -1062.674445 -1062.686254 1.8499 4.5518 4.4671 16.7289 2.3371 4.0649 4.1171 3.8230 2.1848 1.2576 15.6987 16.7144 16.0366 13.6583 14.9210 14.6633 17.6144 19.7195 18.9285 17.4394 15,16-A-NH2BHNBHNH2-G 20,23-A-NH2BHNBHNH2-G 27,28-A-NH2BHNBHNH2-G 32,35-A-NH2BHNBHNH2-G 1,2,4,34,35,36-A-NH2BHNBHNH2-G 3,5,6,7,8,9-A-NH2BHNBHNH2-G 10,11,12,13,14,16-A-NH2BHNBHNH2-G 15,17,18,19,20,21-A-NH2BHNBHNH2-G 22,23,24,25,26,28-A-NH2BHNBHNH2-G 27,29,30,31,32,33-A-NH2BHNBHNH2-G Note: The frequencies calculated are defined as: ν(GHz) ) [(〈∆E〉 × 627.5095 × 4.184 × 1000)/(6.023 × 1023 × 6.62 × 10-34)] × 10-9. -67.90846566 -903.230826 1.3108 14.2874 8,11-A-NH2BHNBHNH2-G Figure 4. Graph of the bonding voltage at different dipole coordinates. a -71.67513456 -903.229604 2.9221 11.7354 3,4-A-NH2BHNBHNH2-G -903.3405631 -205.98009 4.9936 -902.8585749 -64.53652 νr-c ) 2444361.716 GHz, νr-a ) 731005.1317 GHz, νa-c ) 3175366.848 GHz -903.342549 -138.147929 5.7416 -902.8248283 -64.62006 νr-c ) 2674736.927 GHz, νr-a ) 736037.7502 GHz, νa-c ) 3410774.677 GHz -902.125349 4.897124 36.8571 -901.8410913 4.648348 νr-c ) 8884748.358 GHz, νr-a ) 7012041.771 GHz, νa-c ) 1872706.587 GHz -903.335254 -140.822952 2.5053 -902.8423343 -73.55501 νr-c ) 2250388.168 GHz, νr-a ) 996996.0498 GHz, νa-c ) 3247384.218 GHz -903.3360877 -121.742020 28.7027 -902.4849156 296.53608 νr-c ) 4621057.829 GHz, νr-a ) 986514.4475 GHz, νa-c ) 5607572.277 GHz -903.3300934 -130.383929 67.0407 -901.6791866 7.2015672 νr-c ) 8917049.613 GHz, νr-a ) 1959222.299 GHz, νa-c ) 10876271.91 GHz -1062.7829098 3.1764 -1062.3720006 νr-c ) 2109828.629 GHz, νr-a ) 597265.5513 GHz, νa-c ) 2707094.18 GHz -1062.7833884 4.0142 -1062.3684315 νr-c ) 2092008.587 GHz, νr-a ) 641752.0806 GHz, νa-c ) 2733760.668 GHz -1062.7816206 3.8731 -1062.3697555 νr-c ) 2117596.61 GHz, νr-a ) 595795.0964 GHz, νa-c ) 2713391.706 GHz -1062.7809104 3.7538 -1062.3721402 νr-c ) 2106029.954 GHz, νr-a ) 586972.3674 GHz, νa-c ) 2693002.321 GHz -1062.7680881 3.8988 -1062.3571579 νr-c ) 2090306.233 GHz, νr-a ) 616926.2967 GHz, νa-c ) 2707232.529 GHz -1062.7765492 2.0335 -1062.3647987 νr-c ) 2117766.582 GHz, νr-a ) 594870.1329 GHz, νa-c ) 2712636.714 GHz ∆V (au) radical ∆E (Hartree) ∆V (au) cation ∆E (Hartree) r (Debye) ∆V (au) ∆E (Hartree) r (Debye) anion Monajjemi et al. r (Debye) J. Phys. Chem. C, Vol. 114, No. 36, 2010 B18N18-Ala-NH2BHNBHNH2-Gly TABLE 7: Relative Energies (∆E), Radial Coordinate of the Dipole Moment (r), As Well As the Voltage Differences (∆V) and Quantized Transitional Frequencies (∆ν) of the B18N18-Ala-NH2BHNBHNH2-Gly Systema 15328 In other words, the two maximum picks have been observed for the loops with odd numbers (loops 1, 3, 5), and the two minimum picks are seen for loops with even numbers. The negative spin densities in the ∆V range of 13.49334-16.069 au correspond to loops 5 and 1, respectively. In the case of the NH2BHNBHNH2 radical (Figure 5c), similar trends were obvious for loops of the B18N18-NH2BHNBHNH2 system. The graphs of total atomic charges versus isotropic Fermi coupling in different loops of (a) the NH2BHNBHNH2 anion even loops and (b) the NH2BHNBHNH2 anion odd loops in Figure 5, and (c) the NH2BHNBHNH2 radical are exhibited in Figure 6. The same results have been obtained in these graphs for both the NH2BHNBHNH2 anion and the NH2BHNBHNH2 radical forms. 4. Conclusion The procedures discussed in this study place much emphasis on the importance of electronic structure properties of boron nitride rings (BN)n and their electromagnetic nonbonded interaction with the NH2BHNBHNH2 molecule and other biological amino acids to examine the capability of a quantized transition of the NH2BHNBHNH2 molecule inside of the B18N18 ring. Indeed, the NH2BHNBHNH2 inside of the B18N18 ring is supposed as a quantized nanospectrophotometer detector of various quantized parameters of a given biomolecule coupled with this system. Optimized structures, relative stability, HOMO-LUMO band gaps, nuclear quadrupole resonance (NQR), and hyperfine spectroscopic parameters of radical, cationic, and anionic forms of B18N18-NH2BHNBHNH2 systems including total atomic charges, spin densities, electric potential, and isotropic Fermi coupling constants of radical, cationic, and anionic forms of NH2BHNBHNH2 in different loops and bonds of considered system have been compared. The information inferred from NQR study on the local electron density distribution together with analysis of the charge distribution provided logical means for determination of reactive sites and indicated possible promising directions to be followed in the design of (BN)n nanodevices. It has been observed that the radial coordinate of the dipole moment vector (r) as well as the voltage differences (∆V) and relative energies (∆E) exhibited Gaussian distributions. We have obtained a relationship between dipole moments and the voltage differences and the system’s energy. Moreover, the calculation has been repeated for the alanineglycine (Ala-NH2BHNBHNH2-Gly) amino acid coupled with NH2BHNBHNH2 Inside of the B18N18 Nanoring J. Phys. Chem. C, Vol. 114, No. 36, 2010 15329 Figure 5. Graphs of the total atomic spin densities versus isotropic Fermi coupling in different loops of the (a) NH2BHNBHNH2 anion even loops, (b) NH2BHNBHNH2 anion odd loops, and (c) NH2BHNBHNH2 radical. Figure 6. Graphs of the total atomic charges versus the isotropic Fermi coupling in different loops of the (a) NH2BHNBHNH2 anion even loops and (b) NH2BHNBHNH2 anion odd loops. the NH2BHNBHNH2 molecule inside of the B18N18 ring, and the quantized frequencies in different cationic, radical, and anionic forms of NH2BHNBHNH2 have been obtained. Therefore, it seems that these B18N18-NH2BHNBHNH2 systems can be used for the measurement of rotational spectra aroused by electrical voltage differences existing in these amino acids. For further structural information, the LUMO and the HOMO differences, namely, band gaps, have been reported to explore the capability of the suitable NH2BHNBHNH2 candidate which makes a stable B18N18-NH2BHNBHNH2 system. The obtained results confirmed the structural stability of the B18N18 ring and quantized characteristics of radial coordinate, voltage differences (∆V), and relative energies (∆E) which showed Gaussian distribution. Our current analysis is a prerequisite to better clarify their role and to calculate a wide spectrum of ring properties. Indeed, such a considered nanodevice can serve as a nanospectrophotometer detector and supplies a sufficient impetus for further experimental research on the B/N cluster system. References and Notes (1) Curl, R. F.; Smalley, R. E. Science. 1988, 242, 1017. (2) Kroto, H. Science. 1988, 242, 1139. (3) Weltner, W.; Van Zee, R. J Chem. ReV 1989, 89, 1713. 15330 J. Phys. Chem. C, Vol. 114, No. 36, 2010 (4) Locke, I. W.; Darwish, A. D.; Kroto, H. W.; Prassides, K.; Taylor, R.; Walton, D. R. M. Chem. Phys. Lett. 1994, 225, 186. (5) Behrman, E. C.; Foehrweiser, R. K.; Myers, J. R.; French, B. R.; Zandler, M. E. Phys. ReV. A 1994, 49, 1543. (6) Kaxiras, E.; Jackson, K.; Pederson, M. R. Chem. Phys. Lett. 1994, 225, 448. (7) Haubner, R.; Wilhelm, M.; Weissenbacher, R.; Lux, B. High Performance Non-Oxide Ceramics; Springer: New York, 2002; Vol. 102, pp 1-45. (8) Naruhiro, K.; Takeo, O. Solid State Commun. 2004, 131, 121– 124. (9) Blasé, X.; Rubio, A.; Louie, S. G.; Cohen, M. L. Europhys Lett. 1994, 28, 335. (10) Blasé, X.; Charlier, J. C.; de Vita, A.; Car, R. Appl. Phys. Lett. 1997, 70, 197. (11) Miyamoto, Y.; Rubio, A.; Cohen, M. L.; Louie, S. G. Phys. ReV. B 1994, 50, 4976. (12) Chopra, N. G.; Luyken, R. J.; Herrey, K.; Crespi, V. H.; Cohen, M. L.; Louie, S. G.; Zettl, A. Science. 1995, 269, 966. (13) Blasé, X.; Rubio, A.; Louie, S. G.; Cohen, M. L. Europhys. Lett. 1994, 28L, 335. (14) Chopra, N. G.; Luyken, R. J.; Cherrey, K.; Crespi, V. H.; Cohen, M. L.; Louie, S. G. Science. 1995, 269, 966. (15) Golberg, D.; Bando, Y.; Stephan, O.; Kurashima, K. Appl. Phys. Lett. 1998, 73, 2441. (16) Stephan, O.; Bando, Y.; Loiseau, A.; Willaime, F.; Shramchenko, N.; Tamiya, T. Appl. Phys. A 1998, 67, 107. (17) Takeo, O.; Atsushi, N.; Ichihito, N. Physica B 2004, 351, 184– 190. (18) Pokropivny, V. V.; Skorokhod, V. V.; Oleinik, G. S.; Kurdyumov, A. V.; Bartnitskaya, T. S.; Pokropivny, A. V.; Sisonyuk, A. G.; Sheichenko, D. M. J. Solid State Chem. 2000, 154, 214–222. (19) Fowler, P. W.; Heine, T.; Mitchell, D.; Schmidt, R.; Seifert, G. J. Chem. Soc., Faraday Trans. 1996, 92, 2197. (20) Seifert, G.; Flower, P. W.; Mitchell, D.; Porezag, D.; Frauenheim, T. Chem. Phys. Lett. 1997, 268, 352. (21) Alexandre, S. S.; Chacham, H.; Nunes, R. W. Appl. Phys. Lett. 1999, 75, 61. (22) Stankevich, I. V.; Chistyakov, A. L.; Galpern, E. G. Russ. Chem. Bull. 1993, 42, 1634. (23) Tang, A. C.; Li, O. S.; Liu, C. W.; Li, J. Chem. Phys. Lett. 1993, 201, 465. (24) Jensen, F.; Toftlund, H. Chem. Phys. Lett. 1993, 201, 417. (25) Sun, M. L.; Slanina, Z.; Lee, S. L. Chem. Phys. Lett. 1995, 233, 279. Monajjemi et al. (26) Zhukovskii, Y.; SergeiPiskunov, N.; Baiba, B.; Laima, T.; Stefano, B. J. Phys. Chem. Solids 2009, 70, 796–803. (27) Loiseau, A.; Willaime, F.; Demoncy, N.; Schramchenko, N.; Hug, G.; Colliex, C.; Pascard, H. Carbon 1598, 36, 743–752. (28) Iijima, S.; Ichihashi, T. Nature 1993, 363, 603. (29) Ajayan, P. M. Chem. ReV. 1999, 99, 1787. (30) Becke, A. D. J. Chem. Phys. 1993, 98, 5648. (31) Lee, C.; Yang, W.; Parr, R. G. Phys. ReV. B 1998, 37, 785. (32) Golberg, D.; Bando, Y.; Stephan, O.; Kurashima, K. Appl. Phys. Lett. 1998, 73, 2441–2443. (33) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scusera, G. E.; Robb, M. A.; Cheeseman, J. R.; Zakrzewski, V. G.; Montgomery, J. A.; Stratmann, R. E., Jr.; Burant, J. C.; Dapprich, S.; Millam, J. M.; Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J.; Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo, C.; Clifford, S.; Ochterski, J.; Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Cioslowski, J.; Ortiz, J. V.; Baboul, A. G.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Gonzalez, C.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Andres, J. L.; Gonzalez, C.; Head-Gordon, M.; Replogle, E. S.; Pople, J. A. Gaussian 98, revision A.7; Gaussian, Inc.: Pittsburgh, PA, 1998. (34) Zhang, R. B.; Huyskensd, T. Z.; Ceulemeans, A.; Nguyen, M. T. Chem. Phys. 2005, 316, 35–44. (35) Branda, M. M.; Peralta, J. E.; Castellani, N. J.; Contreras, R. H. Surf. Sci. 2002, 504, 235–243. (36) Dumitrescu, S.; Sowerby, D. B. Inorg. Chem. 1992, 32, 3755. (37) Jerosimic, S. V. J. Mol. Spectrosc. 2007, 242, 139–149. (38) Zhu, H. Y.; Klein, D. J.; Seitz, W. A.; March, N. H. Inorg. Chem. 1995, 34, 1377. (39) Rubio, A.; Corkill, J. L.; Cohen, M. L. Phys. ReV. B 1994, 49, 5081. (40) Seifert, G.; Fowler, R. W.; Mitchell, D.; Porezag, D.; Frauenheim, Th. Chem. Phys. Lett. 1997, 268, 352–358. (41) Latosinska, J. N. J. Pharm. Biomed. 2005, 38, 577–587. (42) Lee, V. S.; Nimmanpipuga, P.; Mollaamin, F.; Kungwana, N.; Thanasanvorakunc, S.; Monajjemi, M. Russ. J. Phys. Chem. A 2009, 83, 2288–2296. (43) Henrik, G.; Kjaergaard, A.; Bryan, R. H. Mol. Phys. 1994, 83, 1099– 1116. (44) Rosmusb, P.; Vladimir, G.; Tyutere, V. Chem. Phys. Lett. 2000, 331, 317–322. (45) Fan, J.-F.; Wang, Q.; Qi-Ying, X.; Graaf, V. Chin. J. Struct. Chem. 2002, 21, 139–141. JP104274Z