Active Role of a Germylene Ligand in Promoting Reactions of Platinum Complexes with Oxygen and Sulfur Dioxide.
The reaction of (Et(3)P)(2)PtGe[N(SiMe(3))(2)](2) with dioxygen yields (Et(3)P)(2)Pt(&mgr;-eta(2)-O(2))Ge[N(SiMe(3))(2)](2) (1). Exposure of 1 to light resulted in a rearrangement to (Et(3)P)(2)PtO(2)Ge[N(SiMe(3))(2)](2) (2a), the first example of a bidentate, dianionic germanate ligand. The isomerization was judged to occur via an intramolecular O-O bond scission and rotation of the Pt-Ge bond. No free germylene was detected, and the reaction was found to be zero order. An analogue of 2a was prepared by direct reaction of (Ph(3)P)(2)PtO(2) with Ge[N(SiMe(3))(2)](2) yielding (Ph(3)P)(2)PtO(2)Ge[N(SiMe(3))(2)](2) (2b). Addition of SO(2) to 1 results in the formation of the bridging sulfate (Et(3)P)(2)Pt(&mgr;-eta(2)-SO(4))Ge[N(SiMe(3))(2)](2) (3). An infrared spectroscopy study of the sulfate reaction was performed using oxygen-18. The results indicate that direct insertion of SO(2) into the O-O bond does not occur. Formaldehyde was also observed to insert into the Pt-O bond of 1 giving (Et(3)P)(2)Pt(&mgr;-eta(2)-OCH(2)OO)Ge[N(SiMe(3))(2)](2) (5).
Litz
K. E.
KE
Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055.
Banaszak Holl
M. M.
MM
Kampf
J. W.
JW
Carpenter
G. B.
GB