| Research Abstract |
Inorganic materials with inner cavities such as zeolites are known to bind many organic molecules in the cavity and often exhibit unique catalysis for organic reactions, in which high regio-stereo-, and shape-selectivities are observed. Construction of the inner cavities mainly surroundedby organic componentsis attractive since the shae, size, and function of the cavity become designable.
Thus, a two-dimensional square network material {[Cd (4,4'-bpy)_2] (NO_3)_2} ・ (1) (bpy=bipyridine) was prepared from Cd (NO_3)_2 and 4,4'-bpy. Having inner cavities surroundedby 4,4'-bpy units as shown by crystallographicanalysis, this matcrial behaved like inorganicporous materials such as zeolites. Thus, the complex 1 easily formed the clathrate complex {[Cd (4,4'-bpy)_2] (NO_3)_2・2G}・(2, G=o-C_6H_4X_2 or C_6h_5X,X=Br, Cl) with some aromatic compounds and exhibited heterogeneous catalysis for cyanosilylation of aldegydes.X-ray diffractin study of 2 (G=o- C_6H_4Br_2) showed the layred array of the two-dimensional network.
We also showed the enclathration of a relatively wide variety of aromatic guests by a "swellable" two-dimensional network assembling from cadmium (II) and flexible ligand PyCH_2C_6F_4CH_2Py (3). That is, this network is constructedif the guest is small, but is expandedif the guest becomes large.
Furthermore, we unprecedentedly observed the appearance of quite different network patterns from almost the same crystallographic molecules : i.e., upon complexation with Cd (NO_3)_2, pyridine-based ligand PyCH_2C_6F_4CH_2Py (4) gave an indinite molecular ladder, while ligand 4 afforded an infinite molecular brick despite the very similar unit crystal structures of these complexes.
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