On the efficiency of the photosensitized production of singlet oxygen in water suspensions of a tris(bipyridyl)ruthenium(II) complex covalently boundto an insoluble hydrophilic polymer
Jl. Bourdelande et al., On the efficiency of the photosensitized production of singlet oxygen in water suspensions of a tris(bipyridyl)ruthenium(II) complex covalently boundto an insoluble hydrophilic polymer, J PHOTOCH A, 138(1), 2001, pp. 65-68
Citations number
14
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
It is shown that molecular oxygen in D2O is efficient in deactivating the l
owest excited state of an insoluble hydrophilic polymeric equivalent of [Ru
(bpy)(3)](2+) (see structure 1). The rate constant for quenching by molecul
ar oxygen of the lowest excited triplet charge transfer state of 1 in D2O s
aturated gel is found to be 4.4 +/- 0.5 x 10(8) M-1 s(-1). Singlet molecula
r oxygen, which is characterized by its emission at 1270 nm, is generated d
uring quenching and decays with a lifetime of 18 +/- 3 mus. The lifetimes f
or the decay of singlet oxygen, when it is generated by exciting D2O-solved
sensitizers in the presence and absence of the unfunctionalized polymeric
skeleton in the form of a D2O saturated gel, are 34+/-3 and 63+/-5 ys, resp
ectively. These shorter lifetimes for singlet oxygen in the polymeric gels
are consistent with quenching of singlet oxygen by the hydroxyl groups pres
ent in the polymer. (C) 2001 Elsevier Science B.V. All rights reserved.