L¹Ga {L¹ = HC[C(Me)N(2,6-iPr₂C₆H₃)]₂} reversibly reacts with E₂Ph₄ (E = Sb, Bi) in a temperature-dependent equilibrium reaction with insertion into the E–E bond and formation of L¹Ga(EPh₂)₂ (E = Sb 1, Bi 2). Analogous findings were observed in the reactions of L²Ga {L² = (C₆H₁₁)₂NC[N(2,6-iPr₂C₆H₃)]₂} with E₂R₄ (R = Ph, Et), yielding L²Ga(EPh₂)₂ (E = Sb 3, Bi 4) and L²Ga(EEt₂)₂ (E = Sb 5, Bi 6). 1–3 and 5 were isolated by fractional crystallization at low temperature, whereas 4 and 6 could not be isolated in their pure form even at low temperature. In contrast, reactions of [Cp*Al]₄ (Cp* = C₅Me₅) with Sb₂R₄ (R = Ph, Et) and Bi₂Et₄ did not proceed with insertion into the E–E bonds but with formation of (Cp*Al)₃E₂ (E = Sb, 7; Bi, 8), whereas the reaction with Bi₂Ph₄ yielded metallic bismuth. 8 was also formed in the reaction of [Cp*Al]₄ and BiEt₃ at ambient temperature, whereas the analogous reaction of [Cp*Al]₄ with SbEt₃ did not yield 7 even under drastic reaction conditions (120 °C, 3 days). In contrast, Cp*Ga and Sb₂R₄ (R = Ph, Et) were found to react only at elevated temperature (120 °C) with formation of antimony metal.

Dedicated to Prof. Peter Jutzi on the occasion of his 80th birthday.