Ta(CNDipp)6: an Isocyanide Analogue of Hexacarbonyltantalum(0)

Hexakis(2,6‐diisopropylphenylisocyanide)tantalum is the first isocyanide analogue of the highly unstable Ta(CO) 6 and represents the only well‐defined zerovalent tantalum complex to be prepared by conventional laboratory methods. Two prior examples of homoleptic Ta 0 complexes are known, Ta(benzene) 2 and Ta(dmpe) 3 , dmpe=1,2‐bis(dimethylphosphano)ethane, but these have only been accessed via ligand co‐condensation with tantalum vapor in a sophisticated metal‐atom reactor. Consistent with its 17‐electron nature, Ta(CNDipp) 6 undergoes facile one‐electron oxidation, reduction, or disproportionation reactions. In this sense, it qualitatively resembles V(CO) 6 , the only paramagnetic homoleptic metal carbonyl isolable under ambient conditions.