Photophysical properties of quinones and their interaction with the photosynthetic reaction centre.
Photophysical properties of tetramethyl-1,4-benzoquinone (TMBQ) and 2,6-dimethoxy-1,4-benzoquinone (DMOBQ) in solution and their interactions with the photosynthetic reaction centre (RC) isolated from the photosynthetic bacterium Rhodobacter sphaeroides have been investigated in this work. For these two benzoquinone derivatives an efficient ISC process which leads to the population of the lowest triplet state of the molecules upon direct excitation was observed. The presence of RC does not alter the properties of the triplet state of DMOBQ suggesting that interactions are negligible; on the other side RC efficiently quenched the T1 state of TMBQ. The behavior is rationalized in terms of redox potentials of quinones and kinetic characteristics of their transients.
Barbafina
Arianna
A
Chemistry Department, University of Perugia, via Elce di Sotto 8, 06123, Perugia, Italy.
Elisei
Fausto
F
Latterini
Loredana
L
Milano
Francesco
F
Agostiano
Angela
A
Trotta
Massimo
M
D018360:Crystallography, X-Ray; D008027:Light; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000187:drug effects* / Q000528:radiation effects; D011487:Protein Conformation; D011809:Quinones / Q000737:chemistry / Q000494:pharmacology*; D012242:Rhodobacter sphaeroides / Q000187:drug effects / Q000528:radiation effects
D045322:Photosynthetic Reaction Center Complex Proteins; D011809:Quinones