Mapping electron transfer pathways in a chromophore-quencher triad
Treadway, Joseph A., Chen, Pingyun, Rutherford, Todd J., Keene, F. Richard, and Meyer, Thomas (1997) Mapping electron transfer pathways in a chromophore-quencher triad. Journal of Physical Chemistry: Part A, 101 (37). pp. 6824-6826.
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View at Publisher Website: http://dx.doi.org/10.1021/jp9716389
A comparative study of the photophysics of the four positional isomers (one trans and three cis) of the chromophore-quencher triad [Ru-II(dmb)(bpyCH(2)PTZ)(bpyCH(2)MV(2+))](4+) (dmb is 4,4'-dimethyl-2,2'-bipyridine, bpyCH(2)PTZ is (4'-methyl-4-(2,2'-bipyridin-4-yl)methyl)phenothiazine, and bpyCH(2)MV(2+) is (4'-methyl-4-(2,2'-bipyridin-4-yl)methyl)-1'-methyl-4,4'-bipyridinium cation) has been undertaken, Following metal-to-ligand charge transfer (MLCT) excitation by laser flash photolysis at 460 or 532, nm, the redox-separated states [Ru-II(dmb)(bpyCH(2)PTZ•+)(bpyCH(2)MV•+)]4+ are formed rapidly (< 5 ns), Quenching of MLCT emission occurs with near unit efficiency for all four isomers. For the trans and cis3 isomers, formation of the redox-separated state is similar to 25% efficient. For back electron transfer from -MV+ to -PTZ(+), ΔG0=-1.14 eV for all four isomers from electrochemical measurements and yet k(ET) varies from 4.5 x 10(6) to 8.7 x 10(6) s(-1) in acetonitrile at 25°C.
|Item Type:||Article (Refereed Research - C1)|
|Keywords:||polypyridyl ligands; nonradiative decay; inverted region; complexes; dependence; ruthenium(ii); separation; molecules; rates|
|FoR Codes:||03 CHEMICAL SCIENCES > 0302 Inorganic Chemistry > 030207 Transition Metal Chemistry @ 100%|
|SEO Codes:||97 EXPANDING KNOWLEDGE > 970103 Expanding Knowledge in the Chemical Sciences @ 100%|
|Deposited On:||09 Aug 2012 11:50|
|Last Modified:||02 Jan 2013 12:36|
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