Tris[(alkylthio)methyl]silanes: Syntheses and structures of chromium, molybdenum, and tungsten complexes with a tripodal thioether ligand

The first member of a new family of tripodal thioether ligands, the methylt ris[(alkylthio)methyl]silanes MeSi(CH2SR)(3) (R = Me), has been synthesized and characterized. Reactivity studies lead to the isolation of the complet e series of group 6 metal carbonyl derivatives {eta(3)-MeSi(CH2SMe)(3)}M(CO )(3) (M = Cr, Mo, W), whose structures have been determined by single-cryst al X-ray diffraction. The three complexes are isomorphous and display disto rted octahedral structures with face-capping tridentate thioether ligands. {eta(3)-MeSi(CH2SMe)(3)}Cr(CO)(3) is monoclinic, P2(1)/c, a = 8.1658(2) Ang strom, b = 15.0563(2) Angstrom, c = 26.5791(3) Angstrom, beta = 90.3653(6)d egrees, V= 3267.74(8) Angstrom(3), Z = 8. {eta(3)-MeSi(CH2SMe)(3)}Mo(CO)(3) is monoclinic, P2(1)/c, a = 8.34630(6) Angstrom, b = 15.2747(2) Angstrom, c = 27.1865(4) Angstrom, beta= 90.8987(9)degrees, V= 3465.44(10) Angstrom(3 ), Z= 8 {eta(3)-MeSi(CH2SMe)(3)}W(CO)(3) is monoclinic, P2(1)/c, a = 8.1582 (2) Angstrom, b = 14.9903(2)Angstrom, c = 26.7268(4) Angstrom, beta = 90.65 68(8)degrees, V= 3268.30(9) Angstrom(3), Z=8.