Synthesis and reactivity of tantalum corrole complexes

Reaction of the free base corrole (Mes(2)(p-OMePh) corrole)H-3 with tantalum trialkyl precursors TaMe3Cl2 and TaBn(3)NtBu resulted in the formation of the tantalum dichloride (1) and tantalum imido (4) corrole complexes via alkane elimination. The X-ray crystal structures of these two compounds have been determined and the structural parameters are discussed. The Ta centre of 1 was found to sit out of the plane of the corrole ring by 0.903 angstrom and is cis-ligated, similarly to what has been reported for group 4 porphyrin complexes. From complex 1 we synthesized the dimethyl derivative (2), the reactivity of which is compared to an analogous tantalum dimethyl porphyrin cation. The imido complex 4 reacted with triphenyl-methanol and 4-methylbenzyl alcohol, resulting in different extents of protonation of the imido group.