# Supplementary Material (ESI) for Chemical Communications
# This journal is © The Royal Society of Chemistry 2004
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Supporting Information
Three-dimensional coordination polymer with (3,4)-connected
net, synthesized from ionic liquid media
Danil N. Dybtsev, Hyungphil Chun and Kimoon Kim*
Contribution from the National Creative Research Initiative Center for Smart
Supramolecules, and Department of Chemistry, Division of Molecular and Life
Sciences, Pohang University of Science and Technology, San 31 Hyojadong, Pohang
790-784, Republic of Korea
Materials and methods.
All the reagents and solvents employed were
commercially available and used as supplied without further purification. FT-IR
spectra were recorded from KBr pellets on a Perkin-Elmer Spectrum GX instrument.
The FT-IR spectra of [Cu3(tpt)4](BF4)3·(tpt)2/3·5H2O (1), 2,4,6-tris(4-pyridyl)-1,3,5triazine (tpt) ligand and butylmethylimidazolium tetrafluoroborate ([bmim]BF4) ionic
liquid are presented in Fig. S1.
The powder XRD diffractograms were obtained on a Bruker D8 Advance system
equipped with Cu sealed tube (λ = 1.54178 Å). Following conditions were used: 40
kV, 40 mA, increment = 0.01º, scan speed = 1 s/step. The experimental diffractogram
of 1 together with simulations based on single-crystal X-ray data are shown in Fig.
S2. According to the XRD data the bulk crystalline material is phase pure as all
significant peak positions and their intensities are accounted for from various
simulations based on the single-crystal data.
TGA data were obtained on a Perkin-Elmer Pyris 1 TGA instrument with a heating
rate of 10 deg/min under N2 atmosphere. According to the result shown in Fig. S3 the
metal-organic framework 1 is stable up to 300 ºC and starts to decompose at higher
temperatures.
Single crystal X-ray diffraction study. A dark violet specimen of 1 (0.5 × 0.5 ×
0.4 mm3) having a rhombic dodecahedral morphology was picked up with paraton oil
on the tip of a glass capillary tube and mounted on a Siemens SMART CCD
diffractometer equipped with a graphite-monochromated Mo-K ( = 0.71073 Å)
radiation source in a cold nitrogen stream (–50 ºC). A conventional hemisphere data
set was collected with the exposure of 20 seconds per each of 1271 frames. The data
were corrected for Lorentz and polarization effects (SAINT), and semi-empirical
absorption corrections based on equivalent reflections were applied (SADABS). A
successful solution was obtained using SIR2002 in the centrosymmetric space group
Ia-3d (No. 230) where there is only one unique copper atom with -4 site symmetry
(multiplicity 24, Wyckoff letter d). Subsequent difference Fourier synthesis and fullmatrix least-squares refinements of the framework atoms with SHELXL-97
converged to R1 = 0.1953 and wR2 = 0.4851 for all 1814 unique reflections
(maximum 2theta = 52), 140 parameters and 66 restraints. The framework atoms
except for Cu1 and N1 were found disordered over two possible positions, and
therefore refined with a split-atom model. The occupancy factors were refined as
linked free variables which allow the occupancies for atoms in each fragment remain
the same. All the non-hydrogen atoms were refined anisotropically, and the hydrogen
atoms were added to their geometrically ideal positions. The resulting difference
Fourier maps revealed that non-coordinating tpt ligands exist as guests and they are
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# This journal is © The Royal Society of Chemistry 2004
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statistically disordered with BF4- ions which also occupy the same voids (based on the
probe radius of 1.2 Å, accessible voids are calculated to be 45 % (9847 Å3) of the unit
cell volume). At this point, the SQUEEZE routine of the PLATON software was
applied to create a new reflection data where contributions from the disordered
solvents and anions are removed from the original data. The refinements on this
‘error-free’ data set converged to R1 = 0.0504, wR2 = 0.1081 and GOF = 1.099 for all
1814 reflections. The residual electron density after accounting all the framework
atoms has also been estimated by the SQUEEZE routine, and was 3568e per unit cell.
This number is reasonably close to the theoretical value of 3600e for 24 BF4- ions
(42e each) and 16 guest tpt ligands (162e each). Although the ‘squeezed’ data
produced excellent results in terms of refinements on the framework atoms, final
refinements were carried out on the original data without a modification. The
refinements continued (on the original data) by assigning atoms of the guest tpt with
the site occupancy factor 0.16667 which was derived from the SQUEEZE
calculations. The unusually short contacts (< 1 Å) between pyridyl rings of adjacent
guest tpt ligands were ignored since, on average, only one out of the six noncoordinating guests are fully occupied. The terminal pyridyl ring of the guest tpt was
restrained to an ideal hexagon with the bond distances of 1.39 Å. The resulting
difference Fourier map revealed one-half of the anion sitting on a -4 axis near the
guest tpt ligands (statistically occupying the same voids). The occupancy of the anion
was fixed to meet the total charge balance. The unusually large thermal parameters for
the anion indicate a disorder which is common to BF4- ions; however, a lot of spurious
difference peaks located near the anion were too weak (< 1 e/Å3) and a reasonable
model could not be found. Therefore, it is noted that the atoms assigned to the anion
must represent only one of the many possibilities for dislocation and/or orientation.
Remaining difference peaks with unnegligible electron density were tentatively
assigned as water molecules. Anisotropic refinements of the guests and anion did not
prove to be a sensible strategy due to the low occupancy and data/parameter ratio.
Final refinements converged to R1 = 0.0966 and 0.1082 for observed (1486) and all
(1814) reflections, respectively, with 160 parameters and 52 restraints. The restraints
include 22 rigid-bond restraints to Uij of two bonded atoms (DELU) in the disordered
framework atoms for the anisotropic refinements were unstable. Disordered atoms of
the terminal pyridyl moiety (C1 – C5) which are almost overlapping have also been
restrained to have similar Uij (SIMU) with the standard deviation of 0.02. The highest
peak and deepest hole in the final difference map were 1.13 and -0.49 eÅ-3,
respectively. The contents of the asymmetric unit are shown in Fig. S4 and S5. A
stereoview of the single network structure in 1 is presented in Fig. S6. The view of
two different tiles of the single net in 1 is presented in Fig. S7. See figure captions for
the details.
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Fig. S1. FT-IR spectra of 1 (black), tpt ligand (red) and [bmim]BF4 ionic
liquid (blue).
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10
20
2 / deg
30
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40
50
Fig. S2. Experimental X-ray powder diffraction patterns for 1 (top, black) and simulated
ones based on the full single-crystal data (middle, red) and after removal of the minor
component of the disordered tpt ligands of the framework in 1 (bottom, blue).
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100
Weight / %
80
60
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20
0
0
100
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300
400
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700
o
Temp / C
Fig. S3. TGA plot for 1. Heating rate: 10 deg·sec-1, N2 atmosphere.
800
900
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Fig. S4. ORTEP view (50 % probability level) of the framework atoms in the
asymmetric unit of 1. The minor component of the disordered part is shown with open
bonds.
Fig. S5. Perspective view showing the guests and anion in the asymmetric unit of 1.
Note that only one-half the anion is unique. The guest tpt, BF4- ion and water
molecules statistically occupy the same voids.
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# This journal is © The Royal Society of Chemistry 2004
Fig. S6. Stereoview of the single net structure in 1. The cubic unit cell is shown by
red, Cu+ ions are shown as green tetrahedra and tpt ligands as blue wire.
Fig. S7. View of the two types of tiles in the single net of 1. Type I tile is shown by
red and orange, type II tile is shown by yellow and orange.
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