Reactions of the Tetrafluoroborate Complex [Mo2Cp2(κ2-F2BF2)(μ-PPh2)2(CO)]BF4 with Mono- and Bidentate Ligands Having E–H bonds (E = O, S, Se, N, P)

The title compound reacted rapidly with CNtBu at room temperature by displacing the BF4– ligand and incorporating three molecules of isocyanide to yield the electron-precise complex [Mo2Cp2(μ-PPh2)2(CNtBu)3(CO)](BF4)2, which was obtained as a mixture of cis and trans isomers. Reaction with several HERn molecules (HERn = HSPh, HSePh, H2PCy) took place with formal elimination of HBF4 and spontaneous carbonylation to give the electron-precise cations [Mo2Cp2(μ-ERn)(μ-PPh2)2(CO)2]+. Reactions with several bidentate ligands (L2H) having acidic E–H bonds (2-hydroxypyridine, 2-mercaptopyridine, cathecol, 2-aminophenol, and 2-aminothiophenol) proceeded analogously with deprotonation of these bonds with the preference E = S > O > N. The N,O-donor ligands yielded 32-electron chelate derivatives of the type [Mo2Cp2(O,N-L2)(μ-PPh2)2(CO)]BF4 (L2 = OC5H4N, OC6H4NH2), whereas the S,N-donors yielded 34-electron, S-bridged complexes [Mo2Cp2(μ-S:S,N-L2)(μ-PPh2)2(CO)]BF4 [L2 = SC5H4N (Mo–Mo = 2.8895(8) A), SC6H4NH2]. Howeve...