Bisgermavinylidene [(Me3SiN=PPh2)(2)C=Ge -> Ge=C(PPh2=NSiMe3)(2)] (1) has been used as a source of unstable germavinylidene for the synthesis of a series of heterobinuclear complexes. The reaction of 1 with stoichiometric amounts of transition metal chlorides MCl2 (M = Mn, Fe) yielded [(Me3SiN=PPh2)(2)(GeCl)CMn(mu-Cl)](2) (2) and [(Me3SiN=PPh2)(2)(GeCl)CFeCl] (3), respectively. Treatment of 1 with Me3SiN3, gave the [2 + 3] cycloaddition product [(Me3SiN=PPh2)(2)CGeN(SiMe3)N=N] (4). While similar reaction of 1 with (Bu-n)(3)SnN3 (Bu-n = n-butyl) and water-borane adduct H2O -> B(C6F5)(3) afforded the 1,2-addition products [(Me3SiN=PPh2){(Bu-n)(3)Sn}CPPh2NSiMe3GeN3] (5) and [HC(PPh2=NSiMe3)(2)Ge(OH)B(C6F5)(3)] (6), respectively. The results suggested that the germanium-carbon bond in germavinylidene is capable of forming addition reaction products. The X-ray structures of 2-6 have been determined.