Elucidation of triplet-multiplet and charge transfer excited states in copper and vanadyl phthalocyanines using combined experimental (magneto)optical spectroscopy and time-dependent density functional theory calculations

Magnetic circular dichroism (MCD) and UV-Vis-NIR spectroscopy were used to investigate the spectroscopic signatures of the triplet-multiplet and other transitions observed in the simplest [Formula: see text] (Pc tBu Cu and Pc (SO3Na)4 Cu) and [Formula: see text] (Pc tBu V=O and TPz (OAr)8 V=O) phthalocyanine systems. Density Functional Theory (DFT) and time-dependent DFT (TDDFT) calculations allowed accurate correlation between the experimental and theoretical data. In particular, similarities between vibronic profiles in Q-band and triplet-multiplet band regions as well as the presence of MCD [Formula: see text]-terms associated with the 0-0 transitions support the relationship between the Q- and triplet-multiplet transitions.