Photosensitization of triplet carotenoid in photosynthetic light-harvesting complex of photosystem II

Journal Article · Thu Mar 10 00:00:00 EST 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100316a033· OSTI ID:7004368

Nechushtai, R; Thornber, J P; Patterson, L K; Fessenden, R W; Levanon, H

A laser photolysis study, on the nanosecond time scale, has been carried out on the major light-harvesting chlorophyll-protein complex of photosystem II (LHC II..beta..). The transient triplet absorption of the isolated LHC II..beta.. has been compared to those of its constituent chromophores in dilute micellar aqueous solutions, namely, chlorophyll a, chlorophyll b, chlorophyll a + chlorophyll b, and chlorophyll a + ..beta..-carotene. The results indicate that the carotenoid in the LHC II..beta.. is photosensitized by triplet chlorophyll a and that the decay of the transient triplet absorption exhibits two transients, one in the approx. 50-ns range and the other in the approx. 10..mu..s time scales. The former transient is light-intensity dependent and is attributed to an annihilation process between two triplets of chlorophyll a, while the latter is due to the decay of the triplet carotenoid to its ground state.

• Research Organization: Univ. of California, Los Angeles (USA)
• OSTI ID: 7004368
• Journal Information: J. Phys. Chem.; (United States), Vol. 92:5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CAROTENOIDS
PHOTOLYSIS
CHLOROPHYLL
ABSORPTION SPECTROSCOPY
CHLOROPHYLL-BINDING PROTEINS
EXCITED STATES
EXPERIMENTAL DATA
GROUND STATES
LASERS
PHOTOSYNTHETIC REACTION CENTERS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ENERGY LEVELS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
SPECTROSCOPY
TERPENES
400500* - Photochemistry