Distinct structures of inorganic–organic supramolecular assemblies based on discrete metallocyclic complexes incorporating flexible imidazole ligands: Syntheses, crystal structures and properties
作者:Li Yang、Guanjun Chang、Liang Luo、Feng Ding、Jingsong You
DOI:10.1016/j.ica.2013.07.014
日期:2013.9
Three new interesting discrete dinuclear metallocyclic complexes, namely, [Pd-2(1)(4)](NO3)(4)center dot 2DMSO center dot 2H(2)O}(n) (4), [Pd-2(2)(2)Br-4](n) (5), and [Pd-2(3)(2)Cl-4]center dot 4DMSO}(n) (6) have been successfully synthesized by the reaction of flexible exo-bidentate imidazole-containing ligands 1,3-bis(imidazol-1-ylmethyl)benzene (1),1,3-bis(imidazol-1-ylmethyl)-5-methylbenzene (2), and 2,6-bis(imidazol-1-ylmethyl)-4-tert-butylphenol (3) with corresponding palladium salts. All these complexes were characterized by NMR spectroscopy in combination with elemental analysis, powder X-ray diffraction (PXRD), single-crystal X-ray diffraction, and thermal gravimetric analysis (TGA), respectively. Though all three complexes involve the similar supramolecular building blocks [2+2] metallocyclic units, under the inducement effect of the organic ligands, compounds 4-6 exhibit delicate geometric diversification of the resulting high-dimensional inorganic-organic supramolecular assemblies (e. g., [4+2] lantern-like cage structure, 1D channel, and 2D undulating framework, respectively). Furthermore, these results demonstrate that the secondary interactions such as intermolecular pi center dot center dot center dot pi stacking interactions and hydrogen bonds could play important roles in the aspect of linking low-dimensional entities into high-dimensional supramolecular frameworks. (C) 2013 Elsevier B. V. All rights reserved.