CHALCOGENOLATO COMPLEXES OF BISMUTH AND ANTIMONY - SYNTHESES, THERMOLYSIS REACTIONS, AND CRYSTAL-STRUCTURE OF SB(SC6H2PR3(I)-2,4,6)(3)

Antimony(III) and bismuth(III) complexes of sterically demanding arenechalcogenolato ligands, M(EC(6)H(2)R'(3)-2,4,6)(3) (E = S or Se; M = Sb or Bi; R' = Me, Pr-i or Bu(t)) have been prepared by either protolysis of the amides M[N(SiMe(3))(2)](3) with arenechalcogenols, or from MCl(3) by halide exchange (M = Bi or Sb). The complexes are monomeric in the solid state and sublime readily. The crystal structure of Sb(SC6H2Pr3i-2,4,6)(3) has been determined by X-ray diffraction. The compound possesses a trigonal-pyramidal geometry, with Sb-S distances of 2.418(2)-2.438(2) Angstrom and S-Sb-S angles of 94.69(7)-98.29(8)degrees. Preliminary X-ray results on Bi(SeC6H2Pr3i-2,4,6)(3) showed that the compounds of Sb and Si are isostructural. Thermolytic decomposition of some of the compounds has been carried out in the solid state. Compounds with R' = Me or Pr-i undergo reductive elimination to give elemental bismuth or antimony. whereas the bulky selenolates M(SeC(6)H(2)Bu(3)(t)-2,4,6)(3) afford M(2)Se(3).