Supporting Information
for
Advanced Materials, adma.200702605
Wiley-VCH 2008
69451 Weinheim, Germany
2
Supporting Information
for
Amorphous Infinite Coordination Polymer Microparticles: A New Class of Selective Hydrogen
Storage Materials**
You-Moon Jeon,† Gerasimos S. Armatas,†† Jungseok Heo,† Mercouri G. Kanatzidis,††, ‡ and Chad A.
Mirkin†, *
[*] †Department of Chemistry and the International Institute for Nanotechnology, Northwestern
University, 2145 Sheridan Road, Evanston, IL 60208-3113, U.S.A. Fax: (1) 847-467-5123. E-mail:
[email protected]. ††Department of Chemistry, Northwestern University, 2145 Sheridan
Road, Evanston, IL 60208-3113, U.S.A. ‡Materials Science Division, Argonne National Laboratory,
Argonne, IL 60439, U.S.A.
[**] CAM acknowledges the ARO, ONR and NSF for support of this work and he is also grateful for a
NIH Director’s Pioneer Award. MGK acknowledges the NSF and DOE for support.
General Methods and Instrument Details
Solvents and all other chemicals were obtained from commercial sources and used as received
unless otherwise noted. Deuterated solvents were purchased from Cambridge Isotope Laboratories Inc.
and used as received. 1H NMR spectra were recorded on a Varian Mercury 300 MHz FT-NMR
spectrometer and referenced relative to residual proton resonances in pyridine-d5 and DMSO-d6. All
chemical shifts are reported in ppm. Infrared spectra of solid samples (KBr pellets) were obtained on a
Thermo Nicolet Nexus 670 FT-IR spectrometer. Emission spectra were obtained on a Jobin Yvon
SPEX Fluorolog fluorometer using quartz cells (10 x 4 mm light path). Electrospray ionization mass
spectra (ESI MS) were recorded on a Micromas Quatro II triple quadrapole mass spectrometer. Matrix
assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) was performed on
samples with a Perseptive Biosystems Voyager Pro DE. Elemental analyses were done by Quantitative
Technologies Inc. Whitehouse, NJ. Gas sorption isotherms were measured on a Micromeritics ASAP
3
2020 sorption analyzer. All scanning electron microscopy (SEM) images and energy dispersive X-ray
(EDX) spectra were obtained using a Hitachi S-4500 cFEG SEM (Electron Probe Instruments Center
(EPIC), NUANCE, Northwestern University) equipped with an Oxford Instruments EDS system. All
optical and fluorescence microscopy images were obtained using a Zeiss Axiovert 100A inverted
optical/fluorescence microscope (Thomwood, NY) equipped with a Penguin 600CL digital camera (HQ
FITC/Bopidy/Fluo3/Dio/EGFP filter sets was used for green emission). Particle size and size
distribution in solution were determined with a Zetasizer Nano-ZS instrument. X-ray crystal data for 4
were collected on a CCD area detector with graphite monochromated Mo Kα (λ=0.71073 �) radiation
with a Bruker SMART-1000 diffractometer.
Gas sorption isotherm of the ICP particle 3. The ICP particles 3 were degassed at 573K under
vacuum (<10-5 mbar) for 12 h and the N2 (77 K) and H2 (77 and 87 K) isotherms were obtained using a
liquid nitrogen bath (77 K) or a liquid argon bath (87 K) respectively. The CO2 (258 K) isotherm was
measured using a Thermo NESLAB RTE-10 refrigerated bath (± 0.01 deg.). The apparent Brumauer-
Emmett-Teller (BET) surface areas were obtained by the adsorption branches of N2 isotherm in the
relative pressure (P/Po) range of 0.02-0.08 and CO2 isotherm in the relative pressure range of 0.03-0.05.
Isosteric heat of adsorption. The ICP particles 3 were degassed at 573K under vacuum (<10-5 mbar)
for 12 h and the H2 isotherms were obtained using a liquid nitrogen bath (77 K) and a liquid argon bath
(87 K) respectively. The hydrogen adsorption isotherms of ICP particle 3 at 77K and 87K were
described and analyzed using the following virial-type equation[1]:
, where p is the pressure in torr, v is the amount H2 adsorbed in mmol/g,
T is the temperature in K, αi and bi are adjustable parameters, and m and n represent the order of
polynomials that required to adequately describe the isotherms. The coverage-dependent isosteric heat
of adsorption, Qst, was calculated according to the following expression:
, where R is the universal gas constant.
4
Figure S1. ORTEP diagram of asymmetric unit of metallomacrocycle 4 and selected labeling
scheme with a 60% ellipsoid probability (Hydrogen atoms have been omitted for clarity). Selected
bond lengths [Å] and angles [°]: Zn(1)-N(3) 2.078, Zn(1)-N(4) 2.069, Zn(1)-N(6) 2.109, Zn(1)-O(7)
1.951, Zn(1)-O(8) 1.948, Zn(2)-O(3) 1.978, Zn(2)⋅⋅⋅O(4) 3.105, Zn(2)-O(9) 2.040, Zn(2)-O(10) 2.559,
Zn(2)-N(7) 2.242, Zn(2)-N(8) 2.196, Zn(2)-N(9) 2.056, Zn(1)⋅⋅⋅Zn(4) distance 11.435, Zn(2)⋅⋅⋅Zn(3)
distance 20.832; N(7)-Zn(2)-N(8) 171.21, N(7)-Zn(2)-N(9) 90.27, N(8)-Zn(2)-N(9) 98.44, O(3)-Zn(2)-
N(7) 86.75, O(3)-Zn(2)-N(8) 91.01, O(3)-Zn(2)-N(9) 112.22, O(3)-Zn(2)-O(9) 108.92, O(3)-Zn(2)-
O(10) 164.34, O(9)-Zn(2)-N(7) 83.12, O(9)-Zn(2)-N(8) 89.59, O(9)-Zn(2)-N(9) 137.83. The Zn2+ ion
in the salen pocket is in a square pyramidal geometry, and the four atoms that constitute the
coordination plane of the salen pocket, N(1), N(2), O(1), and O(2), lie 0.43 Å below the central Zn(4)
ion. A pyridine ligand is in the apical position. The Zn(4)-N(py) distance (2.123 Å) is slightly longer
than the average Zn(4)-N(salen) distance (2.072 Å). These values are similar to those observed in a
rac-1,2-cyclohexanediamino-N,N′-bis(3,5-di-tert-butylsalicylidene)zinc(II) complex: the Zn-N(py)
distance is 2.108 Å, the Zn-N(salen) distance is 2.087 Å, and the Zn atom displacement from the
coordination plane is 0.43 Å.[2]
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Figure S2. Stick representation for the crystal structure of metallomacrocycle 4 (pyridine
molecules in metallomacrocyclic 1-D channels are highlighted with purple color): (a) 3-D packing
diagram, (b) Side-view of 1-D channels. Hydrogen atoms have been omitted for clarity.
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Figure S3. SEM image of ICP particles 3 in large area.
Figure S4. EDX spectrum of ICP particle 3.
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Figure S5. (a) TGA diagrams of 3 and 4, (b) X-ray diffraction patterns for as-synthesized and
evacuated 4 (measured at room temperature and the evacuation was carried out by heating to 100 oC
under vacuum for 12 h). The TGA data reveal that with the exception of an initial weight loss (11.2%,
due to solvent liberation in the range of 100-250 oC, the DMF and toluene solvents were also observed
in 1H NMR spectrum taken after dissolving the ICP particle 3 in pyridine-d5), the ICP particles 3 are
stable up to 400 °C. Moreover, the ICP particles 3 did not show any significant weight loss up to 400 oC after evacuation for 12 h at 300 oC. The macrocycle 4 shows similar thermal behavior to the ICP
particles, exhibiting an initial weight loss of 21.6%, which is close to the calculated value for the five
pyridine molecules (19.8%) present at the start of the analysis (determined by elemental analysis). Note
the difference the number of solvent molecules in this experiment (5 pyridines) as compared with the
number observed by X-ray crystallography (8 pyridines with coordination and 7 free guest pyridines) is
due to the fact that macrocycles are pumped dry under vacuum prior to the TGA analysis.
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Figure S6. The reversible adsorption and desorption isotherms for H2 in 3 (measured at 77 K
after thermal activation under a dynamic vacuum at 300 °C for 12 h and solid lines in isotherms are
visual aids).
Figure S7. Adsorption isotherms for H2 in 3 (measured at 77 K � and 87 K � after thermal
activation under a dynamic vacuum at 300 °C for 12 h and solid lines in isotherms are visual aids).
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Figure S8. Adsorption isotherms of 4 for H2 and N2 (H2 �, N2 �) (measured at 77 K after
thermal activation under a dynamic vacuum at 300 °C for 12 h and solid lines in isotherms are visual
aids).
[1] L. Czepirski, J. Jagiello, Chem. Eng. Sci. 1989, 44, 797. [2] G. A. Morris, H. Zhou, C. L. Stern, S. T. Nguyen, Inorg. Chem. 2001, 40, 3222.