Distinct structures of inorganic-organic supramolecular assemblies based on discrete metallocyclic complexes incorporating flexible imidazole ligands: Syntheses, crystal structures and properties

摘要: Three new interesting discrete dinuclear metallocyclic complexes, namely, {[Pd 2 ( 1 ) 4 ](NO 3 ·2DMSO·2H O} n ), [Pd Br ] 5 and Cl ]·4DMSO} 6 have been successfully synthesized by the reaction of flexible exo-bidentate imidazole-containing ligands 1,3-bis(imidazol-1-ylmethyl)benzene 1,3-bis(imidazol-1-ylmethyl)-5-methylbenzene 2,6-bis(imidazol-1-ylmethyl)-4- tert -butylphenol with corresponding palladium salts. All these complexes were characterized NMR spectroscopy in combination elemental analysis, powder X-ray diffraction (PXRD), single-crystal diffraction, thermal gravimetric analysis (TGA), respectively. Though all three involve similar supramolecular building blocks [2+2] units, under inducement effect organic ligands, compounds – exhibit delicate geometric diversification resulting high-dimensional inorganic–organic assemblies (e.g., [4+2] lantern-like cage structure, 1D channel, 2D undulating framework, respectively). Furthermore, results demonstrate that secondary interactions such as intermolecular π⋯π stacking hydrogen bonds could play important roles aspect linking low-dimensional entities into frameworks.