Lewis base-induced formation of a Ga-Zn cation from a Ga-Zn-Fe-Zn-Ga heteropentanuclear complex.

Heterometallic complexes containing metal-metal bonds provide unique opportunities for exploring unusual bonding and reactivity patterns. Herein we report the synthesis and reactivity of a rare heteropentanuclear complex [L1(Et)GaZnFe(CO)4ZnGa(Et)L1] (2; L1 = {HC(C(Me)N(Dipp))2}, Dipp = 2,6- i Pr2-C6H3), containing a Ga-Zn-Fe-Zn-Ga framework, that was synthesized via salt metathesis reaction of [L1(Et)GaZn(THF)Cl]2 (1) with Na2Fe(CO)4·THF. Reaction of 1 with 2 equivalents of Na2Fe(CO)4·THF in the presence of 4-tert-butylpyridine (4- t BuPy) afforded the salt [L1(Et)GaZnFe(CO)4][Na(4- t BuPy)3] (3). The [L1(Et)GaZnFe(CO)4]- anion was also formed in the reaction of 2 with 4-dimethylaminopyridine (DMAP) together with the [L1(Et)GaZn(DMAP)3]+ cation. Comparable reactions of 2 and 3 with Cp*K yielded L1(Et)GaZnCp* (5), which was also obtained from salt elimination reaction of 1 with Cp*K (Cp* = C5Me5), and the potassium salts [K(THF)3][L1(Et)GaZnFe(CO)4] (6) and [K(DMAP)3][L1(Et)GaZnFe(CO)4] (7), respectively. Combined structural, spectroscopic, and computational studies provide insight into the bonding nature and electronic structure of these heterometallic compounds.