Abstract
We present a femtosecond transient absorption study of chlorophyll b monomers in various solvent environments. Transient absorption spectra and kinetics of chlorophyll b were measured in neat pyridine and acetone. The kinetics were measured also for three samples of chlorophyll b dissolved in 3-methylpentane and titrated with pyridine. Characteristic for all chlorophyll b samples is a very strong excited-state absorption, which significantly affects time-resolved anisotropy values in the wavelength region of our study (600−750 nm). The excited-state absorption spectrum was simulated, and on the basis of time-resolved anisotropy measurements the broad and smooth excited-state absorption band was found to be composed of several transitions to higher excited states. For all of the chlorophyll b samples studied, we observed two fast lifetime components (∼100 fs and 1−3 ps). The former component is assigned to transient hole burning of the inhomogeneously broadened ground-state absorption spectrum, while the latter component, which is sensitive to properties of the solvent, is suggested to arise mainly from solvent relaxation.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call