A series of related 2D coordination polymers based on [copper(II)-4,4′-bpy-carboxylato] building blocks

Different combinations of three building blocks, namely the coordination moiety [copper(II)-4,4′-bpy], a carboxylato co-ligand (formato or acetato) and an anion (ClO4−, NO3− or PF6−), lead to the formation of the three compounds, namely {[Cu3(4,4′-bpy)3(μ-OOCH)4(H2O)2](ClO4)2(H2O)6}n (1), {[Cu(4,4′-bpy)(μ-OOCH)(NO3)]}n (2) and {[Cu2(4,4′-bpy)2(μ-OOCCH3)3](PF6)(H2O)}n (3). The molecular structures determined by single-crystal X-ray diffraction reveal notable (4,4) topology, regardless of the different monocarboxylato groups (formato for 1 and 2 and acetato for 3) and anions. Compound 1, synthesized from Cu(II), 4,4′-bpy, ClO4− and formate as co-ligand, exhibits a 2D coordination network based on trinuclear chain secondary building units. With coordinating NO3− anions (instead of non-coordinating ClO4−), a distinct structural motif, i.e. a 2D framework assembled from dinuclear chain secondary building units, is obtained (compound 2). The replacement of the formate ligands by acetate units in compound 3, gives rise to a 2D framework which is assembled from tetranuclear chain secondary building units. The three new coordination compounds have been characterized and tested for their catalytic properties. All compounds show catalytic activities for the selective cyanosilylation of aldehydes.

Three coordination polymers reveal notable structural disparities, which are obviously due to the different monocarboxylato groups (formato for 1 and 2 and acetato for 3) and anions exhibiting a triple-stranded, double-stranded and quadruple-stranded 2D coordination networks, respectively. Their catalytic properties have been tested.Figure optionsDownload as PowerPoint slide