Reactivity of [M(CO)₄(nbd)] (M = Cr or Mo; nbd = norbornadiene) toward (Ph₂PN)C(Ph)[N(SiMe₃)₂] and C₆H₄{C[N(SiMe₃)₂]-(NPPh₂)}₂-1,4

The interaction of (Ph2PN)C(Ph)[N(SiMe3)2] with 1 equivalent of [M(CO)4(nbd)] (M = Cr or Mo, nbd = norbornadiene) in diethyl ether gave cis-[M(CO)4{(Me3SiN)C(Ph)(NHPPh2}] (M = Cr 1 or Mo 2) in good yield. The interaction of C6H4{C(NPPh2)[N(SiMe3)2]}2-1,4 with 2 equivalents of [M(CO)4(nbd)] (M = Cr or Mo) in tetrahydrofuran gave the symmetric dimer cis-[{M(CO)4} {(Ph2PNH)(Me3SiN)CC6H4C(NSiMe3)(NHPPh2)}] (M = Cr 3 or Mo 4) in moderate yield. However, in diethyl ether, this reaction (M = Mo) gave the unsymmetric cis-[(OC)4Mo{(Ph2PNH)(Me3SiN)CC6H4C[N(SiMe3)2](NPPh2)}Mo(CO)5] 5 in moderate yield. Compounds 1-5 have been fully characterized by analytical and spectroscopic methods and the structures of 3 and 5 have been established by X-ray crystallography. A 1,3-silyl shift mechanism has been proposed for the formation of the products. The NH proton of the bidentate iminophosphine ligand undergoes facile deuterium exchange with D2O at ambient temperature.