Abstract:
Heavier element–element multiple bonds had been long considered inaccessible but have now moved beyond the status of lab curiosities. The number of heteroatomic E13═E15 (E13 = Al, Ga; E15 = N, P, As) multiple bonds is still limited. Due to alternating Lewis acidic and Lewis basic centers, E13=E15 species are prone to oligomerize. Oligomerization should be suppressed by either kinetic, acceptor or donor stabilization.
In this lecture the facile synthesis of pnictaalumenes and -gallenes is described, afforded by the combination of Pnicta-Wittig reagents of the type ArPn(PMe3) (Ar = terphenyls; Pn = P, As) with sources of Al(I) opr Ga(I), respectively. This afforded DipTerPn=AlCp*, compounds with Pn-Al multiple bond character. The reactivities of DipTerPnAlCp* towards small molecules such as CO2, C2H4, C2H2, and azides are discussed.