Role of weak interactions in controlling the topology of coordination polymeric chains in [Pt(CN)4]2− bridged Cu(II) complexes: Syntheses, crystal structure and magnetic studies

Four coordination polymeric complexes, [{Cu2(aepn)2Pt(CN)4·H2O}(H2O){Pt(CN)4}]n, (1), [{Cu(dpt)2Pt(CN)4}]n (2), [{Cu(dien)Pt(CN)4}]n (3) and [{Cu(iprdien)Pt(CN)4}]n (4) (where aepn = N-(2-aminoethyl)-1,3-propanediamine, dpt = 3,3′-imino bispropylamine, dien = diethylenetriamine, iprdien = N′-isopropyldiethylenetriamine), have been synthesized and characterized by X-ray single crystal structure determination and variable temperature magnetic measurements. The formation of the supramolecular assemblies has been rationalized and it has been shown that competition between coordinative forces and hydrogen bonding interactions is crucial in the determination of final solid-state packing. A zig-zag/helical 1D chain (2 and 3) appears when the chelating amine at the Cu(II) center is capable of forming the maximum number of hydrogen bonds, on the other hand when one or more of the amine sites are blocked, due to the prevention of the maximization of hydrogen bonding, (4,2) ribbons (1 and 4) appear. Variable temperature magnetic measurement shows the presence of weak antiferromagnetic interactions in all the complexes.

Four coordination polymers of [Pt(CN)4]2− bridged Cu(II) complexes reveal that zig-zag/helical chains or (4,2) ribbons are the result of competition between hydrogen bonding and coordinative forces.Figure optionsDownload as PowerPoint slide