Treatment of[NMe
4]
3[M
3(CO)
9(
-OEt)(
3-OEt)
2](
1, M = Mo;
2, M = W) with 3 equivof(Ph
3P)AuCl/TlPF
6 affordsM
3(CO)
9(AuPPh
3)
3(
-OEt)(
3-OEt)
2(
3, M = Mo;
4, M = W) in 80%and 89% yields, respectively. The molecular structures of
3 and
4 have been determined byX-ray diffraction methods. Complexes
3 and
4are isomorphous. Variable-temperature
31P{H} and
1H NMR spectra for
3,
4,and related complex[NMe
4][W
3(CO)
9(Au
2(
-dppm))(
-OEt)(
3-OEt)
2] (
6) verifyvalence isomerization in these complexes at ambient conditions.