Synthesis and crystal structure of selenocyanato bridged two dimensional supramolecular coordination compounds of cadmium(ii)

Abstract

Two novel 2D polymers of cadmium(II), [Cd(medien)(SeCN)₂]_n (1) (medien = N″-methyldiethylenetriamine) and [Cd₂(iprdien)(SeCN)₄]_n (2) (iprdien = N′-isopropyldiethylenetriamine) have been synthesized and their molecular structure determined by X-ray crystallography. In complex 1 each octahedral cadmium(II) unit of a 1D coordination chain contains one pendant SeCN, binding through Se. These pendant SeCN form mutual relationships with other 1D chains through non-covalent interactions (H-bonding) giving rise to a 2D infinite sheet like structure. The molecular structure of 2 reveals a 2D infinite coordination polymer possessing alternating N-bonded octahedral and Se-bonded tetrahedral cadmium(II) centres exhibiting symbiotic phenomena. Both complexes undergo melting but complex 1 remains as a supercooled liquid in the temperature region 78–131 °C.