Transient grating spectroscopy in photosynthetic purple bacteria Rhodobacter sphaeroides 2.4.1

Sugisaki, Mitsuru; Ito, Shinji; Fujii, Ritsuko; Nakagawa, Katsunori; Nango, Mamoru; Cogdell, Richard J.; Hashimoto, Hideki

doi:10.1016/j.jlumin.2009.01.027

Cited by 5 publications

(5 citation statements)

References 33 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental result is in good agreement with the theoretical calculation. As shown here, spectral density includes meaningful information; however, there are a few reports on carotenoids bound to pigment-protein complexes [139]. On the other hand, many studies have already been performed on the coherent vibrations that directly reflect the effect of coupling with the surrounding environment in bacteriochlorophyll [140][141][142][143][144][145][146][147].…”

Section: Time-resolved and Coherent Spectroscopies Beyond 100 Fs Timementioning

confidence: 91%

Understanding/unravelling carotenoid excited singlet states

Hashimoto

Uragami

Yukihira

et al. 2018

J. R. Soc. Interface.

Self Cite

View full text Add to dashboard Cite

Carotenoids are essential light-harvesting pigments in natural photosynthesis. They absorb in the blue-green region of the solar spectrum and transfer the absorbed energy to (bacterio-)chlorophylls, and thus expand the wavelength range of light that is able to drive photosynthesis. This process is an example of singlet-singlet excitation energy transfer, and carotenoids serve to enhance the overall efficiency of photosynthetic light reactions. The photochemistry and photophysics of carotenoids have often been interpreted by referring to those of simple polyene molecules that do not possess any functional groups. However, this may not always be wise because carotenoids usually have a number of functional groups that induce the variety of photochemical behaviours in them. These differences can also make the interpretation of the singlet excited states of carotenoids very complicated. In this article, we review the properties of the singlet excited states of carotenoids with the aim of producing as coherent a picture as possible of what is currently known and what needs to be learned.

show abstract

Section: Time-resolved and Coherent Spectroscopies Beyond 100 Fs Timementioning

confidence: 91%

Understanding/unravelling carotenoid excited singlet states

Hashimoto

Uragami

Yukihira

et al. 2018

J. R. Soc. Interface.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The function of coherence in molecular dynamics is another challenging question in quantum biology and specifically in photosynthesis . Vibrational coherences are observed in the decay profile of spheroidene using TG spectroscopy. , The frequencies of these vibrational coherences are in good agreement with the frequencies of Raman modes of the molecule. Here, we present a complementary study that examines the oscillatory components of the ground-state bleaching (GSB) band of spheroidene and spheroidenone.…”

Section: Introductionmentioning

confidence: 92%

Addition of a Carbonyl End Group Increases the Rate of Excited-State Decay in a Carotenoid via Conjugation Extension and Symmetry Breaking

et al. 2018

View full text Add to dashboard Cite

Steady-state absorption, transient absorption, and transient grating spectroscopies were employed to elucidate the role of a conjugated carbonyl group in the photophysics of carotenoids. Spheroidenone and spheroidene have similar molecular structures and differ only in an additional carbonyl group in spheroidenone. Comparison of the optical responses of these two molecules under similar experimental conditions was used to understand the role of this carbonyl group in the structure. It was found that the carbonyl group has two main effects: first, it dramatically increases the depopulation rate of the excited states of the molecule. The lifetimes of all the excited states of spheroidenone were found to be almost half of the ones for spheroidene. Second, the presence of the carbonyl group in the chain alters the decay mechanism to the symmetry-forbidden S1 state of the molecule, so that the higher vibrational levels of the S1 state are populated much more effectively. It was also revealed that for both molecules, the S2/S x → S1(hot) → S1 decay process is not purely sequential and follows a branched model.

show abstract

“…In this paper, ultrashort pulses of sub-20 fs duration have been used to examine the electronic and vibronic decay processes simultaneously. 29 The dynamics of the elementary excitations in spheroidene in and out of antenna proteins have been compared.…”

Section: Introductionmentioning

confidence: 99%

Comparison of transient grating signals from spheroidene in an organic solvent and in pigment-protein complexes fromRhodobacter sphaeroides2.4.1

et al. 2010

Self Cite

View full text Add to dashboard Cite

The concurrent dynamics of the electronic excitation and vibronic oscillations of spheroidene have been investigated by means of the transient grating ͑TG͒ spectroscopy. The third-order optical responses of spheroidene in an organic solvent, in the LH2 light-harvesting antenna complexes, and in chromatophores have been compared in order to investigate the influence of the environment surrounding this photosynthetic pigment. Vibronic coherent oscillations with a period of several tens of femtosecond have been clearly observed superimposed on a slowly varying background, which reflects the electronic dynamics. The dynamics of the coherent oscillations have been analyzed by means of the wavelet analysis. Within our experimental accuracy, the decay times of the C v C and C u C stretching modes and C u CH 3 rocking mode of each specimen are very close. The experimental results have also been analyzed using a Brownian oscillator model. For these numerical calculations, the spectral density for the underdamped modes has been determined from the Raman spectrum of spheroidene. It was found that the low-frequency modes that reflect the influence of the protein environment can be approximated by the overdamped Brownian oscillator. The experimentally observed linear absorption spectra as well as the third-order optical responses, i.e., TG curves, are reproduced very well by these calculations. The close agreement between the experiments and calculations indicates that the Feynmandiagrammatic approach can be applied to express not only the internal conversion but also the intermolecular excitation energy-transfer processes. The vibronic decay rates of spheroidene in LH2 complexes and chromatophores are evaluated to be about 20% larger than in the organic solvent.

show abstract

Transient grating spectroscopy in photosynthetic purple bacteria Rhodobacter sphaeroides 2.4.1

Cited by 5 publications

References 33 publications

Understanding/unravelling carotenoid excited singlet states

Understanding/unravelling carotenoid excited singlet states

Addition of a Carbonyl End Group Increases the Rate of Excited-State Decay in a Carotenoid via Conjugation Extension and Symmetry Breaking

Comparison of transient grating signals from spheroidene in an organic solvent and in pigment-protein complexes fromRhodobacter sphaeroides2.4.1

Contact Info

Product

Resources

About