Кононов / 11
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Time-resolved spectroscopy
Pump-probe spectroscopy
Fluorescence up-conversion
Experimental setup for the dual-beam dispersive detection method. Spatial overlap of the sample liquid beam, pump laser and X-ray is depicted in the upper right inset. Temporal sequence of 400-nm pump and X-ray probe pulses is shown in the upper left inset. HPLC stands for high performance liquid chromatography.
Femtosecond spectroscopy of Tris(bipyridine)ruthenium(II)
Photochemical cycle of [RuII(bpy)3]2+ in a simplified energy level scheme.
Absorption of visible light removes a metal-centered (MC) 4d electron in its 1GS into the (1MLCT) state, where it undergoes ultrafast intersystem crossing into the 3MLCT state, localized onto the bipyridine ligand system. The 3MLCT state decays nonradiatively via the high vibrational levels of the MC ground state and via excited states, and radiatively with a
°uorescence lifetime of »600 ns at room temperature
Transient absorption spectrum of aqueous [RuII(bpy)3]2+ 50 fs and 10 ps after photoexcitation (indicated). Both bleach and electron absorption decrease above 500nm, are probably due to ultrafast geminate recombination. Note the blue shift of »0.25 eV of the excited state absorption due to relaxation within the 3MLCT manifold.
W. Gavelda, PhD Thesis, 2006.
(a)Static absorption spectrum of aqueous
[Ru(bpy)3]2+ in the region of the Ru L3and L2edges
(b)Transient difference absorption spectrum measured 50 ps after photoexcitation.
(c)Excited-state XAS spectrum extracted from spectra a and b
J. Am. Chem. Soc. 9 vol. 128, no. 15, 2006 5009
From: Broadband Femtosecond Fluorescence Spectroscopy of [Ru(bpy)3]2+
Angew. Chem. 2006, 118, 3246 –3248
Figure 1. a) 2D time-resolved luminescence spectrum of aqueous [Ru(bpy)3]2+ under excitation at 25000 cm-1. The red area on the right is due to GVD correction.
b) Luminescence spectra recorded at different time delays.
Femtosecond spectroscopy of Rhodopsin