Self assembly towards the construction of molecular ladder and rectangular grid of cadmium(II)-selenocyanate

Abstract

Two novel polymeric networks of cadmium(II), [Cd₂(ibn)(SeCN)₄]_n (1) (ibn=1,2-diamino-2-methylpropane) and [Cd(pyz)(SeCN)₂]_n (2) (pyz=pyrazine) have been synthesised and their molecular structures have been determined by X-ray crystallography. The polymer 1 consists of two 1D parallel chains of Cd(II), each having alternate tetrahedral (CdSe₄) and octahedral (CdN₆) Cd(II) centres bridged through selenocyanate, exhibiting symbiotic phenomena. The octahedral Cd(II) centre of one chain is linked with the tetrahedral Cd(II) centre of another chain through selenocyanate ligand resulting 1D ladder like structure. The complex 2 is a 2D network of octahedral Cd(II) (CdN₄Se₂) in which doubly selenocyanato bridged 1D coordination polymeric chains are linked through pyrazine ligand in a bc plane forming rectangular grid like structure. Two novel selenocyanate bridged complexes, [Cd₂(ibn)(SeCN)₄]_n 1 (ibn=1,2-diamino-2 methyl propane) and [Cd(pyz)(SeCN)₂]_n 2 (pyz=pyrazine) have been synthesized and structurally characterized. Complex 1 exhibits ladder like structure with alternating tetrahedral (CdSe₄) and octahedral (CdN₆) cadmium(II) environments showing the symbiotic phenomena. Complex 2 possesses rectangular grid like structure in which both selenocynate and pyrazine are involved in bridging.