Time-Resolved Electron Paramagnetic Resonance and Phosphorescence Studies of the Lowest Excited Triplet States of Rh(III) Corrole Complexes

The lowest excited triplet (T1) ππ*
states of gallium (Ga) and various rhodium (Rh) 5,10,15-trispentafluorophenyl
corroles (Cors) were studied in the liquid crystal (LC) E-7 and in
rigid glasses by time-resolved electron paramagnetic resonance (TR-EPR)
spectroscopy. The triplet sublevel energies were experimentally determined
by the alignment of the molecules in the LC and by magnetophotoselection
in the glass. The sublevel scheme of GaCor was determined by calculating
the zero field splitting (ZFS) parameters. Axial ligand effects and
quantum chemical calculations were used for the sublevel assignment
of RhCors. The anisotropic EPR parameters were used to determine the
important higher excited states and the magnitudes of their spin–orbit
coupling (SOC) contributions were evaluated. On the basis of these
results and analyses, the EPR parameters and triplet lifetime were
discussed for each RhCor complex.