Photolysis of methylcobalamin: identification of the relevant excited states involved in Co-C bond scission.
The relevant excited states involved in the photolysis of methylcobalamin (MeCbl) have been examined by means of time-dependent density functional theory (TD-DFT). The low-lying singlet and triplet excited states have been calculated along the Co-C bond at the TD-DFT/BP86/6-31g(d) level of theory in order to investigate the dissociation process of MeCbl. These calculations have shown that the photodissociation is mediated by the repulsive 3(sigmaCo-C --> sigma*Co-C) triplet state. The key metastable photoproduct involved in Co-C bond photolysis was identified as an S1 state having predominantly dCo --> pi*corrin metal-ligand charge transfer (MLCT) character.
Jaworska
Maria
M
Department of Theoretical Chemistry, Institute of Chemistry, University of Silesia, Szkolna 9, PL-40 006 Katowice, Poland.
Lodowski
Piotr
P
Andruniów
Tadeusz
T
Kozlowski
Pawel M
PM