Ylide–Metal Complexes. XI. The Preparation and Properties of VIA Group Metal (Te) Complexes of Alkylidenetriphenylphosphoranes and the Corresponding Selenium Compounds

Reactions of (C6H5)3P=CH2 (L) with TeCl4 of mole ratios 2 : 1 and 3 : 1 yield new compounds: dichlorobis(methylenetriphenylphosphorane)tellurium dichloride, [L2TeCl2]Cl2 (1), and chlorotris(methylenetriphenylphosphorane)tellurium trichloride, [L3TeCl]Cl3 (2), respectively. The reaction of ylide L with compound 1 yields a new compound: tetrakis(methylenetriphenylphosphorane)tellurium tetrachloride, [L4Te]Cl4 (3). The structure of compounds 1–3 is a distorted tetrahedron. The color of 1–3 is yellow. The electronic absorption spectra of compounds 2 and 2 show six absorption bands in the region 200–500 nm in dry dichloromethane. The reactions of ylide L with (C6H5)2SeCl2 of mole ratios 1 : 1 and 2 : 1 yield new compounds: chloro(methylenetriphenylphosphorane)diphenylselenium chloride, [LSe(Cl)(C6H5)2]Cl (9), and bis(methylenetriphenylphosphorane)diphenylselenium dichloride, [L2Se(C6H5)2]Cl2 (11), respectively. The color of the selenium compounds is white. The tellurium and selenium compounds are thermally stable in the solid state.