Indexed by:期刊论文

Date of Publication:2013-05-01

Journal:PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES

Included Journals:SCIE、PubMed、Scopus

Volume:12

Issue:5

Page Number:872-882

ISSN No.:1474-905X

Abstract:A series of ketocoumarin compounds were prepared as heavy atom-free triplet photosensitizers. The photophysical properties of the compounds were studied with steady state and time-resolved spectroscopy. The compounds show absorption in the visible spectral region (molar absorption coefficients are up to epsilon = 136 000 M-1 cm(-1) at 448 nm) and long-lived triplet excited states (tau(T) = 199.7 mu s) upon visible light photoexcitation. The compounds were used as triplet photosensitizers for singlet oxygen (O-1(2))-mediated photooxidation of 1,5-dihydroxylnaphthalene (DHN) to produce juglone. O-1(2) quantum yields of these compounds were determined in the range of 0.28-0.48. The ketocoumarins were also used as triplet photosensitizers for triplet-triplet annihilation (TTA) upconversion, and upconversion quantum yields up to 11.3% were observed. The results are useful for preparation of heavy atom-free triplet photosensitizers and for their application in photocatalysis and TTA upconversion.