MCD and MCPL Characterization of Luminescent Si(IV) and P(V) Tritolylcorroles: The Role of Coordination Number

Two triarylcorrole complexes, (hydroxy)[5,10,15-
tritolylcorrolato]silicon-(TTC)Si(OH) and (dihydroxy)[5,10,15-
tritolylcorrolato]phosphorous-(TTC)P(OH)2, have been investigated
by magnetic circular dichroism (MCD) and magnetic circularly
polarized luminescence (MCPL). The spectroscopic investigations
have been combined with explicit calculation of MCD response
through time-dependent density functional theory (TD-DFT) formal-
ism. This has allowed us to better define the role of molecular orbitals
in the transitions associated with the Soret and Q bands. Besides and
more importantly, MCD has made it possible to follow the titration
process of (TTC)Si(OH) in dimethyl sulfoxide (DMSO) solution
with NaF and of (TTC)P(OH)2 in dichloromethane solution with
alcohols in a complementary and, we dare say, more sensitive way with
respect to absorption and fluorescence data. Finally, the MCPL spectra and the ancillary TD-DFT calculations have allowed us to characterize the excited state of (TTC)Si(OH).