Synthesis and Nucleophilic Behavior of cis-[M(C6F5)2(Ph2PCHPPh2)]- (M = Pd, Pt): C-Alkylation, Metalation, and Halogenation of Coordinated Bis(diphenylphosphino)methane. X-ray Crystal Structure of [Pt(C6F5)2(Ph2PCHIPPh2)]·C5H12

The reaction of the neutral complexes cis -[M(C 6 F 5 ) 2 (Ph 2 PCH 2 PPh 2 )] [M = Pd ( 1a ), Pt ( 1b )] with LDA (lithium diisopropylamide) or Li t Bu ( tert -butyllithium) in THF readily affords the anionic derivatives [M(C 6 F 5 ) 2 (Ph 2 PCHPPh 2 )] - by deprotonation of the coordinated bis(diphenylphosphino)methane (dppm). The reactivity of the carbanionic center thus generated toward a variety of substrates has been studied. The reaction with alkyl halides such as MeI or EtI gives the neutral, C-alkylated complexes cis -[M(C 6 F 5 ) 2 (Ph 2 PCHRPPh 2 )] [M = Pd, R = Me ( 2a ), Et ( 4a ); M = Pt, R = Me ( 2b ), Et ( 4b )], and the reaction with ClAuPPh 3 or O 3 ClOAgPPh 3 gives the heterobimetallic species cis -M(C 6 F 5 ) 2 [Ph 2 PCH(M‘PPh 3 )PPh 2 ] [M = Pd, M‘ = Au ( 5a ), Ag ( 6a ); M = Pt, M‘ = Au ( 5b ), Ag ( 6b )], in which the [Ph 2 PCHPPh 2 ] - ligand acts as a bridging, tridentate- P,P ‘,C ligand. The reactions with halogens (Cl 2, Br 2, I 2 ) or pentafluorophenyl halides (BrC 6 F 5, IC 6 F 5 ) produce the heterolytic cleavage of the X−X or X−C bond, giving the halogenated derivatives cis -[M(C 6 F 5 ) 2 (Ph 2 PCHXPPh 2 )] [M = Pd, X = I ( 9a ); M = Pt, X = Cl ( 7b ), Br ( 8b ), I ( 9b )]. The reaction of [Pt(C 6 F 5 ) 2 (Ph 2 PCHPPh 2 )] - with C 6 F 5 CN occurs with C−F bond cleavage, and the para-substituted product M(C 6 F 5 ) 2 [Ph 2 PCH(C 6 F 4 CN-4)PPh 2 ] ( 10b ) is obtained. The X-ray crystal structure of 9b ·C 5 H 12 is reported.