Author/Authors :
Pozdnyakov، نويسنده , , Ivan P. and Kolomeets، نويسنده , , Alexander V. and Plyusnin، نويسنده , , Victor F. and Melnikov، نويسنده , , Alexey A. and Kompanets، نويسنده , , Victor O. and Chekalin، نويسنده , , Sergey V. and Tkachenko، نويسنده , , Nikolai and Lemmetyinen، نويسنده , , Helge، نويسنده ,
Abstract :
Femtosecond pump–probe spectroscopy was used to determine the photophysical processes of Fe(III) complexes with citric and tartaric acids ([Fe(Cit)] and [Fe(tart)]+) in aqueous solutions. The excitation of the complexes in the charge transfer bands is followed by formation of an intermediate absorbance decaying with two characteristic times. The shorter time constant (0.2, 0.4 ps) is ascribed to vibrational cooling and solvent relaxation of Frank–Condon excited state of corresponding complex and the second time constant (1.4, 40 ps) is assigned to superposition of internal conversion to the ground state and formation of the long-lived Fe(II) radical complex. The competition of these processes determines the quantum yield of photolysis of Fe(III)–carboxylates.