Monomeric β-Diketiminato Group 13 Metal Dipnictogenide Complexes with Two Terminal EH Groups (E=P, As).

The pnictogenyl Group 13 compounds (Dipp Nacnac)M[E(SiMe ) ]Cl and (Dipp Nacnac)M(EH ) (Dipp Nacnac=HC[C(Me)N(Ar)] , Ar: Dipp=2,6-iPr C H ; M=Al, Ga, In; E=P, As) were successfully synthesized. The salt metathesis between (Dipp Nacnac)MCl and LiE(SiMe ) only led to monosubstituted compounds (Dipp Nacnac)M[E(SiMe ) ]Cl [E=P, M=Ga(1), In (2); E=As, M=Ga (3), In (4)], regardless of the stoichiometric ratios used. In contrast to the steric effect of the SiMe groups in 1-4, the reactions of the corresponding halides with LiPH ⋅DME (or KAsH ) facilely yielded the dipnictogenide compounds (Dipp Nacnac)M(EH ) (E=P, M=Al (5), Ga (6), In (7); E=As, M=Al (8), Ga (9)), avoiding the use of flammable and toxic PH and AsH for their synthesis. The compounds 5-9 are the first examples of monomeric Group 13 diphosphanides and diarsanides in which the metal center is bound to two terminal PH and AsH groups, respectively. In contrast to the successful synthesis of the indium diphosphanide (Dipp Nacnac)In(PH ) , the reaction of (Dipp Nacnac)InCl with KAsH led to an indium mirror due to the instability of the target product.