Synthesis and spectral studies on mixed ligand complexes of Cd(II) dithiocarbamates with nitrogen donors: single crystal X-ray structure of bis(4-methylpiperidinecarbodithioato-S,S′)(1,10-phenanthroline)cadmium(II)

Abstract

The current article describes the synthesis and characterization of the following adducts: [Cd(2-mpipdtc)₂(1,10-phen)], [Cd(2-mpipdtc)₂(bipy)], [Cd(4-mpipdtc)₂(1,10-phen)], [Cd(4-mpipdtc)₂(bipy)] (where 2-mpipdtc⁻ = 2-methylpiperidinecarbodithioate anion, 4-mpipdtc⁻ = 4-methylpiperidinecarbodithioate anion, 1,10-phen = 1,10-phenanthroline and bipy = 2,2′-bipyridine). A single crystal X-ray structural analysis was carried out for [Cd(4-mpipdtc)₂(1,10-phen)]. IR spectra of the complexes show the contribution of the thioureide form to the structures. Reduction in ν_C–N(thioureide) for the mixed ligand complexes is attributed to the change in coordination number from four to six and the steric effect exerted by 1,10-phenanthroline or 2,2′-bipyridine. Deshielding of the protons adjacent to nitrogen in the ¹H NMR spectra is attributed to drift of electrons from the nitrogen of NR₂, forcing electron density towards sulfur via the thioureide π-system. Single crystal X-ray structural analysis of [Cd(4-mpipdtc)₂(1,10-phen)] showed that the cadmium is in a distorted octahedral environment with a CdS₄N₂ chromophore. The presence of 1,10-phenanthroline in the coordination sphere of Cd(dtc)₂ increases the Cd–S distances and decreases the S–Cd–S angles. VBS analysis supports the determined structure.

Keywords:

• Dithiocarbamates
• Cadmium
• X-ray structure
• VBS analysis

Acknowledgements

We are thankful to SAIF, Indian Institute of Technology, Madras for the single crystal X-ray structural analysis and SAIF, Lucknow for providing C, H, N, and S analysis data.

Notes

¹ CCDC-671821 contains the supplementary crystallographic data for this article. These data can be obtained free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge Crystallographic Data Center, 12 Union Road, Cambridge, CB2 1EZ, UK, Fax: [phone], E-mail: [email protected] or at www: http://www.ccdc.cam.ac.uk].