Coherent Processes in Molecular Crystals

Burland, D. M.; Zewail, Ahmed H.

doi:10.1002/9780470142592.ch6

Cited by 52 publications

(4 citation statements)

References 197 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The exciton states are separated in lower (as) and upper (s) branches. This reflects the interactions within a dimer and is commonly known as Davydov splitting (Davydov, 1948;Wolf, 1967;Robinson, 1970;Silbey, 1976;Burland & Zewail, 1979) (see Fig. 28,…”

Section: B850mentioning

confidence: 99%

The architecture and function of the light-harvesting apparatus of purple bacteria: from single molecules to in vivo membranes

Cogdell

Gall

Köhler

2006

Quart. Rev. Biophys.

653

734

View full text Add to dashboard Cite

This review describes the structures of the two major integral membrane pigment complexes, the RC-LH1 'core' and LH2 complexes, which together make up the light-harvesting system present in typical purple photosynthetic bacteria. The antenna complexes serve to absorb incident solar radiation and to transfer it to the reaction centres, where it is used to 'power' the photosynthetic redox reaction and ultimately leads to the synthesis of ATP. Our current understanding of the biosynthesis and assembly of the LH and RC complexes is described, with special emphasis on the roles of the newly described bacteriophytochromes. Using both the structural information and that obtained from a wide variety of biophysical techniques, the details of each of the different energy-transfer reactions that occur, between the absorption of a photon and the charge separation in the RC, are described. Special emphasis is given to show how the use of single-molecule spectroscopy has provided a more detailed understanding of the molecular mechanisms involved in the energy-transfer processes. We have tried, with the help of an Appendix, to make the details of the quantum mechanics that are required to appreciate these molecular mechanisms, accessible to mathematically illiterate biologists. The elegance of the purple bacterial light-harvesting system lies in the way in which it has cleverly exploited quantum mechanics.

show abstract

Section: B850mentioning

confidence: 99%

The architecture and function of the light-harvesting apparatus of purple bacteria: from single molecules to in vivo membranes

Cogdell

Gall

Köhler

2006

Quart. Rev. Biophys.

653

734

View full text Add to dashboard Cite

show abstract

“…Figure 4 shows the energy transfer rate k H G obtained experimentally. The solid line gives the result from pulsed excitation experiments analysed using equation ( 7) while the broken line gives the result from the steady state experiments according to equation (6). In both cases the K + concentration has been used for ρ.…”

Section: Singlet Excitonsmentioning

confidence: 99%

“…Because these systems are very complex, model systems are investigated for which it is hoped that the energy transfer processes are closely related to those in biology. The most intensively investigated model systems are organic molecular crystals [3][4][5][6][7][8][9]. In these systems the intramolecular interactions are much stronger than the intermolecular forces.…”

Section: Introductionmentioning

confidence: 99%

Frenkel excitons in : excitation energy transfer and exciton coherence

Köhler¹,

Schmid²

1996

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

A review is presented about sensitized luminescence and luminescence lineshape studies on pure and doped sodium nitrite which have led to detailed knowledge about the lowest excited states of this system. Both the lowest triplet state and the first excited singlet state are Frenkel excitons, states that can migrate through the crystal. This migration is appropriately described by a one-dimensional energy transfer process for the triplet and, surprisingly, also for the singlet state. The exciton states themselves show an evolution in time that reveal the transition from coherent to incoherent behaviour with increasing temperature. In combination with theoretical investigations a consistent picture of the exciton states in sodium nitrite is achieved.

show abstract

“…This showed that the coherent description of the pair states was correct, at least at liquid He temperatures. There were a number of other groups that contributed to the study of dimers (and one-dimensional molecular excitons [14][15][16]) in this period.…”

Section: Introductionmentioning

confidence: 99%