Stark absorption spectroscopy of peridinin and allene-modified analogues

Kusumoto, Toshiyuki; Horibe, Tomoko; Kajikawa, Takayuki; Hasegawa, Shinji; Iwashita, Takashi; Cogdell, Richard J.; Birge, Robert R.; Frank, Harry A.; Katsumura, Shigeo; Hashimoto, Hideki

doi:10.1016/j.chemphys.2010.01.018

Cited by 25 publications

(31 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Carotenoids with carbonyl substitution such as fucoxanthin [59] and peridinin [58,[60][61][62] would be expected to be especially prone to the formation of an enhanced ICT character because the addition of an electron-withdrawing group in conjugation increases the tendency to fully transfer charge across a twisting C=C bond. In peridinin, for example, Stark absorption experiments [63,64] reveal that a very large change in permanent dipole moment accompanies the S0 → S2 optical transition, so even in the planar Franck-Condon structure the conjugated backbone has an asymmetric distribution of π electrons along its length. The resulting enhancement of the asymmetry or polarization of the biradical character [55] would be expected to strongly favor a full transfer of charge and pyramidalization.…”

Section: Intramolecular Charge Transfer and The S* Statementioning

confidence: 99%

Excited state conformational dynamics in carotenoids: Dark intermediates and excitation energy transfer

Beck

Bishop

Roscioli

et al. 2015

Archives of Biochemistry and Biophysics

Self Cite

View full text Add to dashboard Cite

A consideration of the excited state potential energy surfaces of carotenoids develops a new hypothesis for the nature of the conformational motions that follow optical preparation of the S2 (1(1)Bu(+)) state. After an initial displacement from the Franck-Condon geometry along bond length alternation coordinates, it is suggested that carotenoids pass over a transition-state barrier leading to twisted conformations. This hypothesis leads to assignments for several dark intermediate states encountered in femtosecond spectroscopic studies. The Sx state is assigned to the structure reached upon the onset of torsional motions near the transition state barrier that divides planar and twisted structures on the S2 state potential energy surface. The X state, detected recently in two-dimensional electronic spectra, corresponds to a twisted structure well past the barrier and approaching the S2 state torsional minimum. Lastly, the S(∗) state is assigned to a low lying S1 state structure with intramolecular charge transfer character (ICT) and a pyramidal conformation. It follows that the bent and twisted structures of carotenoids that are found in photosynthetic light-harvesting proteins yield excited-state structures that favor the development of an ICT character and optimized energy transfer yields to (bacterio)chlorophyll acceptors.

show abstract

Section: Intramolecular Charge Transfer and The S* Statementioning

confidence: 99%

Excited state conformational dynamics in carotenoids: Dark intermediates and excitation energy transfer

Beck

Bishop

Roscioli

et al. 2015

Archives of Biochemistry and Biophysics

Self Cite

View full text Add to dashboard Cite

show abstract

“…To account for this observation, an intramolecular charge transfer (ICT) state has been postulated to exist in the excited singlet state manifold (Bautista et al 1999a;Frank et al 2000). This idea has been supported by theoretical computations (Vaswani et al 2003) and experiments on numerous carbonyl-containing carotenoids and polyenals Kopczynski et al 2007;Kusumoto et al 2010;Papagiannakis 2004;Premvardhan et al 2005;Stalke et al 2008;Van Tassle et al 2007;Wild et al 2006;Zigmantas et al 2001Zigmantas et al , 2002Zigmantas et al , 2003Zigmantas et al , 2004. The studies suggest that alterations in the polarity of amino acids in the vicinity of peridinin bound in its natural protein environment may provide a mechanism by which light-harvesting may be regulated in the PCP complex (Polívka et al 2007).…”

Section: Introductionmentioning

confidence: 97%

Triplet state spectra and dynamics of peridinin analogs having different extents of π-electron conjugation

et al. 2010

Self Cite

View full text Add to dashboard Cite

The Peridinin-Chlorophyll a-Protein (PCP) complex has both an exceptionally efficient light-harvesting ability and a highly effective protective capacity against photodynamic reactions involving singlet oxygen. These functions can be attributed to presence of a substantial amount of the highly-substituted and complex carotenoid, peridinin, in the protein and the facts that the low-lying singlet states of peridinin are higher in energy than those of chlorophyll (Chl) a, but the lowest-lying triplet state of peridinin is below that of Chl a. Thus, singlet energy can be transferred from peridinin to Chl a, but the Chl a triplet state is quenched before it can sensitize the formation of singlet oxygen. The present investigation takes advantage of Chl a as an effective triplet state donor to peridinin and explores the triplet state spectra and dynamics of a systematic series of peridinin analogs having different numbers of conjugated carbon-carbon double bonds. The carotenoids investigated are peridinin, which has a C(37) carbon skeleton and eight conjugated carbon-carbon double bonds, and three synthetic analogs: C(33)-peridinin, having two less double bonds than peridinin, C(35)-peridinin which has one less double bond than peridinin, and C(39)-peridinin which has one more double bond than peridinin. In this study, the behavior of the triplet state spectra and kinetics exhibited by these molecules has been investigated in polar and nonpolar solvents and reveals a substantial effect of both pi-electron conjugated chain length and solvent environment on the spectral lineshapes. However, only a small dependence of these factors is observed on the kinetics of triplet energy transfer from Chl a and on carotenoid triplet state deactivation to the ground state.

show abstract

“…These results strongly suggest that the allene group of peridinin is essential for formation of the effective ICT state, which would allow the quantitative energy transfer to Chl a in the PCP complex. This is the first experimental evidence that shows the allene group in peridinin enhances the ICT character (Kusumoto et al, 2010). In addition, as the results of peridinin and polyene chain modified derivatives, peridinin (1) also showed the largest || value among all of them.…”

Section: Measurement Of Stark Spectramentioning

confidence: 63%

An Approach Based on Synthetic Organic Chemistry Toward Elucidation of Highly Efficient Energy Transfer Ability of Peridinin in Photosynthesis

Kajikawa¹,

Katsumura²

2012

Artificial Photosynthesis

Self Cite

View full text Add to dashboard Cite

Stark absorption spectroscopy of peridinin and allene-modified analogues

Cited by 25 publications

References 26 publications

Excited state conformational dynamics in carotenoids: Dark intermediates and excitation energy transfer

Excited state conformational dynamics in carotenoids: Dark intermediates and excitation energy transfer

Triplet state spectra and dynamics of peridinin analogs having different extents of π-electron conjugation

An Approach Based on Synthetic Organic Chemistry Toward Elucidation of Highly Efficient Energy Transfer Ability of Peridinin in Photosynthesis

Contact Info

Product

Resources

About