Synthesis and spectral evaluation of 5,10,15,20-tetrakis(3,4-dibenzyloxyphenyl) porphyrin

Porphyrins are of interest in many applications that involve electron transfer and absorption of light, such as solar energy and photodynamic cancer therapy. The newly synthesized 5,10,15,20-tetrakis(3,4-dibenzyloxyphenyl) porphyrin, TDBOPP, was characterized using H-1 NMR, C-13 NMR, UV-vis and fluorescence spectroscopy and MALDI-TOF/TOF high resolution mass spectrometry. Standard H-1 NMR and C-13 NMR experiments coupled with nuclear Overhauser effect (NOE) experiments confirmed the structure of the compound. The expected M+ and [M + H](+) ions are observed in the MALDI-TOF/TOF mass spectrum. The UV-vis absorption spectrum of TDBOPP shows a Soret band at 424 nm and three Q bands at 519 nm, 556 nm, and 650 nm with molar absorptivity 3.6 x 10(5) cm(-1)m(-1), 1.6 x 10(4) cm(-1)m(-1), 1.0 x 10(4) cm(-1)m(-1) and 5.3 x 10(3) cm(-1)m(-1), respectively. Excitation at 424 nm gives emission at 650 nm. The quantum yield of the porphyrin is 0.11.