Synthesis, spectral characterization, crystal structures and catalytic activity of a series of lanthanide(III) azepane dithiocarbamate complexes

A series of lanthanide(III) azepane dithiocarbamate (Aze-Dtc) complexes, [Ln(Aze-Dtc)(3)(Phen)] where Ln = La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III) and Er(III), have been synthesized under mild reaction conditions with excellent yields. The new complexes have been structurally characterized by analytical (CHNS) and various spectral techniques, such as FT-IR. UV-Vis, CV and H-1 NMR. The coordination mode of the ligands and the geometry of [Pr(Aze-Dtc)(3)(Phen)], [Nd(Aze-Dtc)(3)(Phen)], [Sm(Aze-Dtc)(3)(Phen)] and [Dy(Aze-Dtc)(3)(Phen)] were confirmed by single crystal X-ray studies. In these complexes the central Ln(III) atom possess a distorted dodecahedral geometry with six sulfur atoms of three Aze-Dtc ligands and two nitrogen atoms of a 1,10-phenanthroline ligand coordinated to it. The utility of these complexes as catalysts in trimethylsilylcyanation of carbonyl compounds has also been screened. The results indicate that the catalytic activity shown by these complexes is good to excellent. (C) 2013 Elsevier Ltd. All rights reserved.