Preparation and characterization of some stereochemically rigid seven-coordinate cyclopentadienylzirconium(IV) Tris-N,N-dialkyldithiocarbamate complexes

Abstract

Zirconium(IV) N,N-dialkyldithiocarbamates of the type CpZr(S2CNR2)3 where R = Me, Et have been prepared by reaction of dicyclopentadienylzirconium(IV) dichloride with sodium salts of substi- tuted dithiocarbamic acids in aqueous and non-aqueous media. They have also been prepared by reaction of cyclopentadienylzirconium(~) trichloride with sodium salts of substituted dithiocarbamic acids in non-aqueous medium. Conductance and infrared studies show that these complexes are non-electrolytes in which all of the dithiocarbamate ligands are bidentate. Therefore, a coordination number of ?seven? may be assigned to the zirconium(IV) atom in these compounds. Proton N.M.R. spectra of these complexes in carbon disulphide or deuterated chloroform indicate that there is hindered rotation about C-N single bonds at ambient temperature, and that metal-centred rearrangement is slow on the N.M.R. time scale at ambient temperature (30�).