Fluorescence quenching of meso-tetrakis (4-sulfonatophenyl) porphyrin by colloidal TiO(2).
A stable colloidal TiO(2) has been prepared. The interaction of meso-tetrakis (4-sulfonatophenyl) porphyrin (TSPP) with colloidal TiO(2) was studied by absorption and fluorescence spectroscopy. Upon excitation of its absorption band, the fluorescence emission of TSPP was quenched by colloidal TiO(2). The bimolecular quenching rate constant (k(q)) is 1.78 x 10(11)M(-1)s(-1). The porphyrin can participate in the quenching process by injecting electrons from its excited states into the conduction band of TiO(2). The quenching mechanism is discussed on the basis of the quenching rate constant as well as the reduction potential of the colloidal TiO(2). Rehm-Weller equation was applied for the calculation of free energy change (DeltaG(et)).
Kathiravan
A
A
School of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India.
Anbazhagan
V
V
Asha Jhonsi
M
M
Renganathan
R
R
D003102:Colloids; D004583:Electrons; D005453:Fluorescence; D011166:Porphyrins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*
D003102:Colloids; D011166:Porphyrins; C092400:meso-tetrakis(4-sulfonatophenyl)porphyrin; C009495:titanium dioxide; D014025:Titanium