Journal of Physical Chemistry A, Vol.102, No.28, 5659-5664, 1998
Photophysical and photochemical investigation of a dodecafluorosubphthalocyanine derivative
The photochemical and photophysical behavior of (dodecafluorosubphthalocyanaoto)boron(III) chloride was examined in room-temperature solutions. The lowest energy absorption maximum of the complex is 570 nm, and the luminescence mirrors the absorption with a maximum at 586 nm (Stokes shift = 480 cm(-1)). The emission is strong, with a quantum yield in deaerated acetonitrile of 0.66 and a lifetime of 2.6 ns. The complex exhibits a reversible one-electron reduction in cyclic voltammetry (E degrees = -0.53 V vs SCE), and this, combined with the relatively high singlet energy, indicates the emissive excited state is a strong oxidant. Evaluation of the free energy dependence of the emission quenching with a series of substituted benzene donors yields a value of 1.7 V vs SCE for the excited-state reduction potential, E(*/-), The excited complex also reacts with tertiary amines. Photolysis in the presence of triphenylamine results in photoinduced electron transfer and back reaction. Triethylamine, however, reacts efficiently with the excited subphthalocyanine to yield a permanent photoproduct. The product has been characterized by FAB mass spectrometry as well as H-1 and F-19 NMR to be an adduct involving B-N bond formation.