Direct Metal–Metal Bonds Between High and Low Valent Complex Fragments: The Reaction of Metal Bases with the Metal Acids [Re(NR)3]+ and [Mo(NR)2]2+

Shortened metal–metal bonds caused by electrostatic attraction within the dipolar (metalδ+ – metalδ−) structural unit were observed in the heterobi‐ and heterotrimetallic complexes of type 1 and 2. These complexes were synthesized from the imido complexes [(NtBu)3ReCl] or [(NtBu)2MoCl2] and the carbonyl metalates K[M]. [M] = CpMo(CO)3, CpW(CO)3, Mn(CO)5, CpFe(CO)2, Co(CO)4. equation image