Photosynthetic light harvesting: excitons and coherence. The absorption spectra of intact cells could also be recorded for each illuminated area directly on the Petri dish, using a Cary 50 spectrophotometer, and compared with the nonilluminated area. The absorption band extends from 350 nm to 500 nm, with two maxima at around 430 nm and 480 nm. Quantum coherence in photosynthesis for efficient solar-energy conversion. The absorption spectrum measured with our TO spectrometer is shown in the following graph. Romero E., Augulis R., Novoderezhkin V.I., Ferretti M., Thieme J., Zigmantas D., van Grondelle R. Application to the Light-Harvesting Complex II in the Presence of Resonant Vibrational Modes. Scalable High-Performance Algorithm for the Simulation of Exciton Dynamics. Springer Dordrecht, The Netherlands: 2006.Ĭao J., Cogdell R.J., Coker D.F., Duan H.-G., Hauer J., Kleinekathöfer U., Jansen T.L.C., Mančal T., Miller R.J.D., Ogilvie J.P., et al. Chlorophylls and Bacteriochlorophylls: Biochemistry, Biophysics, Functions and Applications. Grimm B., Porra R.J., Rüdiger W., Scheer H. Qy state TD-DFT CAM-B3LYP calculations anti-Stokes excitation spectroscopy chlorophyll a fluorescence lifetime near-infrared absorption tail photosynthesis vibronic transitions. Long vibronic red tails are, thus, expected to exist in all pigments of light-harvesting relevance at physiological temperatures. A similar tail was observed earlier in the case of bacteriochlorophyll a, suggesting generality of this phenomenon. Chlorophyll a absorbs light more effectively at higher wavelengths ( > 600 nm. The shape of the spectrum as well as its temperature dependence were qualitatively well reproduced by quantum chemical calculations involving the pigment intramolecular vibrational modes, their overtones, and pairwise combination modes, but no intermolecular/solvent modes. absorption spectra in the photosynthetically active region, 400 to 720 nm. The tail also weakened rapidly upon cooling the sample, implying its basic thermally activated nature. Theoretical considerations concerning the relation between chlorophyll flu- orescence and photosynthesis in green plant cells. The quasi-exponentially decreasing tail was, at ambient temperature, readily observable as far as -2400 cm -1 from the absorption peak and at relative intensity of 10 -7. A weak absorption tail related to the Q y singlet electronic transition of solvated chlorophyll a is discovered using sensitive anti-Stokes fluorescence excitation spectroscopy.

Absorption spectra of chlorophyll a