Mt. Tierney et al., Photoinduced electron transfer in an oligodeoxynucleotide duplex: Observation of the electron-transfer intermediate, J PHYS CH B, 104(32), 2000, pp. 7574-7576
Kinetics of a photoinduced electron-transfer reaction between phenothiazine
(PTZ) and Ru(bpy)(2)(4-m-4'-pa-bpy)(2+) [bpy = 2,2'-bipyridine and 4-m-4'-
pa-bpy = 4-methyl-4'-carbonylpropargylamine] covalently bound to a DNA dupl
ex is investigated by transient absorption spectroscopy. The electron donor
, PTZ, is attached to the 5' terminal of one oligodeoxynucleotide strand, a
nd the chromophore, Ru(bpy)2(4-m-4'-pa-bpy)2+, is covalently linked to a ur
idine of the complementary strand. Electron transfer between the donor, PTZ
, and photoexcited acceptor, *Ru(bpy)(2)(4-m-4'-pa-bpy)(2+), occurs, and th
e product of the forward electron-transfer reaction, PTZ(+.), is observed.
The rate of the back electron-transfer reaction (k(b) = 3.94 x 10(6) s(-1);
Delta G similar to 2.0 eV) is determined by monitoring the decay of the el
ectron-transfer intermediate, PTZ(+.), by transient absorption spectroscopy
.