Synthesis and structural characterization of three new cadmium(II) coordination polymers containing thiocyanato and pyridyl ligands

Author： Suen Maw-Cherng Wang Ju-Chun

Publisher： Taylor & Francis Ltd

ISSN： 0095-8972

Source： Journal of Coordination Chemistry, Vol.60, Iss.3, 2007-01, pp. : 257-268

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

The reaction of Cd(NO3)2 · 4H2O with NH4SCN and dpa (dpa = 2,2'-dipyridylamine) in CH3OH afforded the complex [Cd(SCN)2(dpa)]n (1), while reaction of Cd(NO3)2 · 4H2O with NH4SCN and pca (pca = 2,2'-dipicolylamine) in CH3OH gave complexes of the type [Cd(SCN)2(pca)]n (2). The reaction of Cd(NO3)2 · 4H2O with NH4SCN, H2ox (H2ox = oxalic acid) and amp (amp = 2-aminopyridine) in CH3OH gave complexes of the type {[Cd(NCS)2(ox)](Hamp)2}n (3). Their IR spectra have been recorded and their structures determined. Complex 1 shows 1-D polymeric double-stranded chains with bridging thiocyanato groups. The double-stranded linear chains in 1 have eight-membered rings and close-pack to form the 3-D structures through C-H · S hydrogen bonding and π-π interactions. In the pseudo {CdN5S} octahedral complex 2, the nitrogen containing ligands occupy amine and pyridyl groups of the fac-pca ligand and two nitrogen atoms and one sulfur atom from the two bridging and one monodentate NCS- ligands, forming the 1-D polymeric helical chain. Complex 3 shows a 3-D supramolecular structure by weak S · S interactions among the 2-D ionic sheets to contain each cadmium octahedrally coordinated by two cis sulfur atoms, two cis nitrogen atoms from four μ(N,S) bridging thiocyanato groups and two oxygen atoms from the chelating oxalate ligands.