The first example of a (Te, O, N) type of hybrid organotellurium ligand N-[2-(4-methoxyphenyltelluro)ethyl]phthalimide (1)
has been made by reaction of N-(2-bromoethyl)phthalimide with the nucleophile 4-MeOC6HaTe - generated in situ by borohydride reduction of bis(4-methoxyphenyl)ditelluride under a nitrogen atmosphere. Palladium(II) complexes of 1, namely
[PdCI2.1] , [PdCI.I]CIO 4 (2), [(Ph3P)2Pd.1](CIO4) 2 (3) and [(DPPE)Pd.1](C104) 2 (4), where DPPE---PhaPCH2CHzPPh 2 have been synthesized. In all the complexes except 2 the ligand 1 is coordinated through N and Te, as indicated by deshielding (0.1-0.7 ppm) of the CH2Te and CH2N signals in their 1H NMR spectra with respect to those for free 1, and a red shift (10-25 cm -1) in v(Te-C) alkyl-aryl. Complex 2 was found to be a 1:1 electrolyte and the ligand 1 in this complex is coordinated through oxygen as well as the through N and Te, as indicated by a red shift (30 cm -1) in the v(C=O) band of I on complexation.
Complexes 3 and 4 were found to be 1 : 2 electrolytes. The presence of CHC13 in [PdCI2.1], 3 and 4 was revealed by weight losses in thermogravimetric analysis at 65-70°C. The UV-visible spectra of all the complexes suggest a square planar geometry of the ligands around palladium.