(LGa)-Ga-1 {L-1 = HC[C(Me)N(2,6-iPr(2)C(6)H(3))]2} reversibly reacts with E2Ph4 (E = Sb, Bi) in a temperature-dependent equilibrium reaction with insertion into the E-E bond and formation of (LGa)-Ga-1(EPh2)(2) (E = Sb 1, Bi 2). Analogous findings were observed in the reactions of (LGa)-Ga-2 {L-2 = (C6H11)(2)NC[N(2,6-iPr(2)C(6)H(3))](2)} with E2R4 (R = Ph, Et), yielding (LGa)-Ga-2(EPh2)(2) (E = Sb 3, Bi 4) and (LGa)-Ga-2(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)(3)E-2 (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 degrees C, 3 days). In contrast, Cp*Ga and Sb2R4 (R = Ph, Et) were found to react only at elevated temperature (120 degrees C) with formation of antimony metal.