Germanium(III) corrole complex: reactivity and mechanistic studies of visible-light promoted N-H bond activations

The [(TPFC)Ge(TEMPO)] (1, TPFC = tris(pentafluorophenyl)corrole, TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxyl) complex was characterized by X-ray diffraction and spectroscopic studies. EPR studies indicate that the weak Ge-O bond in 1 is photo-cleaved to form a tetra-coordinated germanium(m) radical, [(TPFC)Ge(III)](center dot). DFT calculations show that the spin density on the germanium center in [(TPFC)Ge(III)](center dot). has a significant s character. Under visible-light irradiation, 1 reacts rapidly with ammonia, primary/secondary aliphatic amines and aniline to produce (TPFC)Ge-(NRR2)-R-1 ((RR2)-R-1 = HH, (HPr)-Pr-n, (HPr)-Pr-i, (HBu)-Bu-t, HPh, Et-2, Pr-i(2)) complexes in high yields (65-95%).