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 arene chalcogenolato ligands, M(EC(6)H(2)R'(3)-2,4,6)(3) (E = S or Se; M = S b or Bi; R' = Me, Pr-i or Bu(t)) have been prepared by either protolys is of the amides M[N(SiMe(3))(2)](3) with arenechalcogenols, or from M Cl(3) by halide exchange (M = Bi or Sb). The complexes are monomeric i n the solid state and sublime readily. The crystal structure of Sb(SC6 H2Pr3i-2,4,6)(3) has been determined by X-ray diffraction. The compoun d possesses a trigonal-pyramidal geometry, with Sb-S distances of 2.41 8(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 c ompounds of Sb and Si are isostructural. Thermolytic decomposition of some of the compounds has been carried out in the solid state. Compoun ds with R' = Me or Pr-i undergo reductive elimination to give elementa l bismuth or antimony. whereas the bulky selenolates M(SeC(6)H(2)Bu(3) (t)-2,4,6)(3) afford M(2)Se(3).