Morphology-Selective Formation and Morphology-Dependent Gas-Adsorption Properties of Coordination Polymer Particles
✍ Scribed by Hee Jung Lee; Won Cho; Soyoung Jung; Moonhyun Oh
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 388 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0935-9648
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✦ Synopsis
Coordination polymers are very useful materials in catalysis, optics, recognition, and separation. [1] In particular, there is an enormous interest in the storage of gas molecules, that is, H 2 , CO 2 , C 2 H 2 , etc. [2] Although the vast majority of coordination polymer materials, including metal-organic frameworks (MOFs), are focused on macroscaled crystalline products, for structural studies based on single-crystal X-ray analysis, we and others have recently reported the synthetic strategies for the preparation of nano-and microsized coordination polymer particles (CPPs). [3,4] In contrast to bulk coordination polymers, CPPs have considerable potential for use in innovative applications, such as imaging probes and heterogeneous catalysts. [3] Furthermore, CPPs also provide the opportunity for the fine tuning of materials, to achieve the properties desired. [4a,b] On the other hand, manipulation of the chemical and physical properties of metal or semiconductor particles through morphology control is a well-known strategy. [5] However, no research related to morphology-dependent properties in CPPs has been performed. Herein, we report the selective formation of CPPs with diverse shapes from the same basic building blocks. We also demonstrate that the gas-sorption properties of CPPs, despite their identical chemical compositions, vary according to the morphology of the particles.
A carboxyl-functionalized ligand (H 2 L ¼ 2,6-bis[(4-carboxyanilino)carbonyl]pyridine, Fig. ) was synthesized according to the literature with slight modifications. Subsequently, CPPs were prepared by the following solvothermal reactions. H 2 L, In(NO 3 ) 3 Á xH 2 O, imidazole, and CH 3 CO 2 H were combined in dimethylformamide (DMF), and the resulting solution was heated at 80 8C for 10 min. After this time, the precipitated products were cooled to room temperature, collected by centrifugation, and rinsed several times with DMF and methanol.
The morphology of the resulting products was characterized by field-emission scanning electron microscopy (SEM), optical microscopy (OM), and fluorescence microscopy (FM), as shown in Figure . The images reveal the formation of elongated hexagonal particles (CPP-6), with an average width and length of 1.52 and 3.00 mm, respectively. Infrared spectroscopy was used to confirm the creation of coordination polymers, as evidenced by a COMMUNICATION www.advmat.de