1D chain, 2D layer and trinuclear unit based 3D frameworks of indium(iii)-biphenyl carboxylate complexes

Abstract

Four indium(III)-biphenyl carboxylate coordination complexes: [In(dpdc)(bipy)Cl]2 (1), {[In(Hdptc)(bipy)]2·H2O}n (2), [In(dptc)·H3O]n (3), [In3(μ2-OH)2(Hdptc)(dptc)H2O]n (4) (H2dpdc=diphenyl-2,2′-dicarboxylic acid, bipy=2,2′-bipyridine, H4dptc=biphenyl-2,2′,6,6′-tetracarboxylic acid) have been synthesized under hydrothermal and solvothermal conditions. Complex 1 exhibits a dimeric molecule structure featuring a square motif organized by two In(III) ions and two dpdc ligands each at the corner; 2 contains a similar dimeric segment which is extended into a 1D ribbon structure by the Hdptc ligands and further assembled into 2D supramolecular layer through hydrogen bonding; 3 features a 2D (4,4) grid layer, which is assembled into 3D supramolecular network through hydrogen bonding with guest water molecules. Complex 4 consists of an unprecedented eight-connected trinuclear In3(μ2-O)2(CO2)8 building unit which is jointed by four-connected dptc ligand into a binodal (4,8)-connected scu topology. The results present a feasible way of manipulation to control the dimensionality of the complexes by adjusting ligands and reaction temperatures. The complexes are also characterized by X-ray powder diffractions (PXRD), infrared spectroscopy and elemental analysis.