Monomeric β-Diketiminato Group 13 Metal Dipnictogenide Complexes with Two Terminal EH2 Groups (E=P, As).

Abstract

The pnictogenyl Group 13 compounds (Dipp2Nacnac)M[E(SiMe3)2]Cl and (Dipp2Nacnac)M(EH2)2 (Dipp2Nacnac=HC[C(Me)N(Ar)]2, Ar: Dipp=2,6‐iPr2C6H3; M=Al, Ga, In; E=P, As) were successfully synthesized. The salt metathesis between (Dipp2Nacnac)MCl2 and LiE(SiMe3)2 only led to monosubstituted compounds (Dipp2Nacnac)M[E(SiMe3)2]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 SiMe3 groups in 1–4, the reactions of the corresponding halides with LiPH2⋅DME (or KAsH2) facilely yielded the dipnictogenide compounds (Dipp2Nacnac)M(EH2)2 (E=P, M=Al (5), Ga (6), In (7); E=As, M=Al (8), Ga (9)), avoiding the use of flammable and toxic PH3 and AsH3 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 PH2 and AsH2 groups, respectively. In contrast to the successful synthesis of the indium diphosphanide (Dipp2Nacnac)In(PH2)2, the reaction of (Dipp2Nacnac)InCl2 with KAsH2 led to an indium mirror due to the instability of the target product.