Polymeric structure and solid NMR spectra of cadmuim (II) dialkyldithiophosphates (alkyl = propyl, butyl, isopropyl and isobutyl)

By dropwise adding thio ligands to concentrated aqueous solutions of Cd(ClO4)26H2O, polymeric complexes, Cd(II) O,O′-dipropyl-dithiophosphate (1), O,O′-dibutyl- dithiophosphate (2), O,O′-diisopropyi-dithiophosphate (3) and O,O′-diisobutyl-dithiophosphate (4) were obtained. The structure of 4 was determined by X-ray diffraction analysis, showing that the metal ion sits in distorted tetrahedral sulphur coordination sphere and that the eight-membered bimetallic rings take the twist chair and boat conformations, alternately. Based on facts that the S(1)-Cd bond length [0.25099(12) nm] is shorter than the other S-Cd bond length [0.25399(12)-0.25701(18) nm] and that the S(1)-involving angles [113.45(4)°-118.43(5)°] are systematically larger than the normal angles of a tetrahedron, the ligands are hypothesized to be erratically functionalized to Cd(II). To certify the steric nonequivalence of ligands, the compounds were investigated by solid 13C, 31P and 113Cd NMR spectroscopy.