The gold siloxanes Me(3)PAuOSiMe(3) (1) and Ph(3)PAuOSiPh(3) (2) were
prepared from the corresponding (phosphine) gord(I) chlorides and sodi
um silanolates in dichloromethane as colorless, stable, crystalline so
lids. The crystal structure of compound 1 (monoclinic, space group C2/
c, Z=8) has been determined by X-ray methods. The lattice contains cen
tro-symmetrical dimers with short Au-Au contacts (3.376(2) Angstrom).
The Si-O-Au angle is 121.0(4)degrees; the coordination geometry at the
gold atom is close to linear. The hexaphenyl compound 2 is assumed to
be a monomer like the methylpentaphenyl analog MePh(2)PAuOSiPh(3), ow
ing to steric effects. The thiosiloxane (silylthiolate) Ph(3)PAuSSiPh(
3) (3) was obtained from Ph(3)PAu(acac) and Ph(3)SiSH in CH2Cl2. It cr
ystallizes in the monoclinic space group P2(1)/n with Z=4 molecules in
the unit cell. The compound is a monomer in the crystal with a narrow
angle at the sulfur atom (95.0(1)degrees) and a linear coordination g
eometry at the gold atom. Association is again prevented by steric eff
ects.