PHOTOPHYSICAL AND PHOTOCHEMICAL INVESTIGATION OF A DODECAFLUOROSUBPHTHALOCYANINE DERIVATIVE

The photochemical and photophysical behavior of (dodecafluorosubphthal ocyanaoto)boron(III) chloride was examined in room-temperature solutio ns. The lowest energy absorption maximum of the complex is 570 nm, and the luminescence mirrors the absorption with a maximum at 586 nm (Sto kes 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 comple x exhibits a reversible one-electron reduction in cyclic voltammetry ( E degrees = -0.53 V vs SCE), and this, combined with the relatively hi gh singlet energy, indicates the emissive excited state is a strong ox idant. Evaluation of the free energy dependence of the emission quench ing with a series of substituted benzene donors yields a value of 1.7 V vs SCE for the excited-state reduction potential, E(/-), The excite d 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 b een characterized by FAB mass spectrometry as well as H-1 and F-19 NMR to be an adduct involving B-N bond formation.