Y. Harima et al., PHOSPHORESCENCE AND S-T ABSORPTION IN VANADYL(IV) TETRAPHENYLPORPHYRIN AT ROOM-TEMPERATURE, Chemical physics letters, 267(5-6), 1997, pp. 481-484
Contrary to an early view, vanadyl(IV) tetraphenylporphyrin (VOTPP) in
solution and its vacuum-sublimed film at room temperature are found t
o be luminescent in the near-infrared. Luminescence lifetimes of VOTPP
in chloroform at room temperature and 77 K are evaluated as 60 ns and
2.2 mu s, respectively. In addition, a weak light absorption ascribab
le to a singlet-to-triplet excitation is found at 733 nm with a molar
extinction coefficient of 5 M(-1) cm(-1).