title: Temperature-dependent time-resolved fluorescence study of cinchonine alkaloid dication.
abstract: Photo induced excited state dynamical processes of cinchonine alkaloid dication (C(++)) have been studied over a wide range of temperature using steady state and nanosecond time-resolved fluorescence spectroscopic techniques. The temperature-dependent fluorescence studies of C(++) clearly indicate the existence of two distinct emitting species having their own characteristic decay rates. The shorter-lived species shows a usual temperature dependence with increasing non-radiative deactivation at higher temperatures, while the longer-lived species show features resembling to the excited state solvent relaxation process with a large solvent relaxation time (tau(r) approximately 6 ns). The species emitting in the lower energy side, having longer decay time is found to be more sensitive towards chloride ion quenching and has a charge transfer character. Further, concentration quenching with decrease in tau(r) of long lived species shows the possibility of energy migration along with solvent relaxation in C(++).
authors: Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012 India. hirdyesh@mbu.iisc.ernet.in
authors: Hirdyesh
authors: H
authors: Mishra
authors: Sanjay
authors: S
authors: Pant
authors: Hera B
authors: HB
authors: Tripathi
mesh_terms: D000962:Antimalarials / Q000737:chemistry*; D002930:Cinchona Alkaloids / Q000737:chemistry*; D004735:Energy Transfer; D005453:Fluorescence; D010777:Photochemistry; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013997:Time Factors
chemical_list: D000962:Antimalarials; D002930:Cinchona Alkaloids; C010086:cinchonine
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