Two-dimensional sheet based upon C-H∙∙∙N hydrogen
bonds within an organic co-crystal: a crystallographic,
spectroscopic, and theoretical study
Dylan Kimballa, James Starnesa, Ryan H. Groenemanb*, Herman R. Krueger, Jr.b, and Eric W.
Reinheimera*
a
Department of Chemistry and Biochemistry and the W.M. Keck Foundation Center for
Molecular Structure, California State University, 333 S. Twin Oaks Valley Rd., San Marcos, CA,
92096, USA; Email: eric.reinheimer@rigaku.com
b
Department of Biological Sciences, Webster University, 470 E. Lockwood Ave., St. Louis, MO,
63119, USA; Email: ryangroeneman19@webster.edu
______________________________________________________________________________
Supporting Information
Infrared Spectroscopy
Figure S1. Infrared spectrum for (TCNB)∙(4,4’-BPE) 1.
Figure S2. Infrared spectrum for free TCNB.
Theoretical Calculations
The following tables contain computations on the C-H∙∙∙N(ring) and C-H∙∙∙N(CN)
interactions within 1 and on the (TCNB)∙(TMP) 2 system of Sawka-Dobrowolska et.al (1). In
the case of 1 when employing crystallography data, the positions of the hydrogen atoms were set
to match bond lengths determined for optimized goemetries. For computations involving the
crystallographically determined geometries, the interaction energy represents the (negative of)
the energy to dissociate the complex into its fragments with the fragments retaining the geometry
that they possess in the complex.
In the case of computations involving optimized geometries, the fragments are allowed to
relax to final equilibrium geometries following dissociation. The use of optomized geometries
allows one to include this more rigorous “fragment relaxation” in the BSSE correction. As the
results demonstrate, however, these further refinements only alter the computed values by a few
tenths of a kcal/mol. The value of ZPE used for a given hydrogen bonding interaction was at
the harmonic level obtained from B3LYP/6-311++G(d,p) optimizations. This value was 0.67
kcal/mol for the C-H∙∙∙N(ring) interaction and 0.53 kcal/mol for the C-H∙∙∙N(CN) interaction.
Values of H298 were computed from the formula:
H298 = Eel + BSSE + ZPE + Evib + Erot +Etrans + ( n)RT
In this formula, the vibrational temperature correction to E, Evib, was computed at the
B3LYP/6-311++G(d,p) level on optimized geometries, and the result used for computations at
all levels. The values of Etrans and Erot were taken as the classical value (-3/2 RT for each)
and n = -1 for the formation of the complex from two fragments.
In the case of TMP-TCNB, a crystal geometry was utilized with the rings oriented at a
ninety degree angle as depicted in figure 7b by Sawka-Dobrowolska et al (1). In all tables,
missing entries represent quantities requiring unreasonably long computation time, or ones
deemed unnecessary for the current consideration.
Table S1. Interaction Energies for C-H∙∙∙N(ring) Hydrogen Bond
Model
Level of
theory
Basis
set
Crystal geometry for complex
and fragments
Crystal geometry for complex
and fragments
DFT
(B3LYP)
DFT
(B3LYP)
6-311
G(d,p)
6311++
Eel
Eel+BSSE
(kcal/mol) (kcal/mol)
-7.50
-6.02
Eel+ BSSE +
ZPE
(kcal/mol)
-5.35
-6.26
-5.97
-5.30
H298
(kcal/mol)
-4.47
-4.52
Optimized geometry for
complex with fragment
relaxation.
Crystal geometry for complex
and fragments
DFT
(B3LYP)
DFT
(M062X)
Crystal geometry for complex
and fragments
MP2
DFT(B3LYP/6-311++G(d,p))
geometry for complex. Same
geometries for separate
fragments
Crystal geometry for complex
and fragments
MP2
MP2
G(d,p)
6311++
G(d,p)
6311++
G(d,p)
6311++
G(d,p)
6311++
G(d,p)
aug-ccpVTZ
-6.56
-6.06
-5.38
-4.55
-7.90
-7.52
-6.85
-6.02
-9.42
-7.72
-7.04
-6.21
-9.75
---
---
---
-9.88
-8.92
-8.25
-7.42
Table S2. Interaction Energies for the C-H∙∙∙N(CN) Hydrogen Bond
Model
Level of
theory
Basis
set
Crystal geometry for complex
and fragments
DFT
(B3LYP)
Crystal geometry for complex
and fragments
DFT
(M062X)
MP2
6311++
G(d,p)
6311++
G(d,p)
6311++
G(d,p)
Crystal geometry for complex
and fragments
Eel
Eel+BSSE
(kcal/mol) (kcal/mol)
-1.01
-0.77
Eel+ BSSE +
ZPE
(kcal/mol)
-0.24
H298
(kcal/mol)
-3.10
-2.75
-2.22
-1.30
-4.72
-3.43
-2.90
-1.98
.68
Table S3. Interaction Energies for TMP-TCNB, 90o Orientation of Rings (see , Chemical
Physics 2006, 327, 237-246).
Model
Level of
theory
Basis
set
Eel
Eel+BSSE
(kcal/mol) (kcal/mol)
Geometry from figure 7b, Chemical
Physics 2006, 327, 237-246 Same
geometry for fragments.
Geometry from figure 7b, Chemical
Physics 2006, 327, 237-246 Same
geometry for fragments.
Geometry from figure 7b, Chemical
Physics 2006, 327, 237-246 Same
geometry for fragments.
DFT
(B3LYP)
6-311
G(d,p)
-4.66
-3.67
Eel+ BSSE +
ZPE
(kcal/mol)
---
DFT
(M062X)
MP2
6-311
G(d,p)
-6.67
-5.82
---
6-311
G(d,p)
-8.01
-6.29
---
References
1.
Sawka-Dobrowolska, W.; Bator, G. ; Czarnik-Matusewicz, B.; Sobczyk, L.;
Pawlukojć, A.; Grech, E.; Nowicka-Scheibe, J.; Rundlőf, H. Chemical Physics 2006, 327, 237246.