Theory Forster

The FRET efficiency (E) is highly dependent on the distance between donor and acceptor and is defined by Forsters theory [105] ... 

A detailed theory of energy transfer by the Coulombic mechanism was developed by Forster, so the process is often referred to as Forster resonance energy transfer (FRET). According to the Forster theory, the probability of Coulombic energy transfer falls off inversely with the sixth power of the distance between the donor and the acceptor. For... 

Figure 6.11 The dependence of the efficiency of energy transfer, Er, on the donor-acceptor distance, R, according to the Forster theory...

The theory describing the light-harvesting effects suggests going beyond the dipole-dipole approximation of Forster theory [67, 68], Its development for modeling the natural systems of photosynthesis is beneficial for the design of fluorescence reporters. 

May V (2009) Beyond the Forster theory of excitation energy transfer importance of higher-order processes in supramolecular antenna systems. Dalton Trans 45 10086-105... 

Wong KF, Bagchi B, Rossky PJ (2004) Distance and orientation dependence of excitation transfer rates in conjugated systems beyond the Forster theory. J Phys Chem A 108 5752-5763... 

Because this chapter will be mainly concerned with the Forster mechanism of transfer, the results of the Forster theory, given in Section 4.6.3, are recalled here for convenience. The rate constant for transfer between a donor and an acceptor at... 

One would still like to examine the effect of ethidium on the torsional rigidity and dynamics at high binding ratios. One would also like to test the Forster theory for excitation transfer between bound ethidium molecules, since it has been questioned/65- This is possible in principle by deconvoluting the effects of depolarization by excitation transfer on the FPA, as will be shown subsequently. DLS also provides crucial information on this same question. 

Scholes GD, Jordanides XJ, Fleming GR (2001) Adapting the Forster theory of energy transfer for modeling dynamics in aggregated molecular assemblies. J Phys Chem B 105 1640... 

The validity of the Forster theory was tested and confirmed in a number of model studies with compounds that contained a donor and an acceptor separated by well-defined rigid spacers. This work has been reviewed 5] In a classical study, a naphthyl group (donor) was attached to the C-terminal and a dansyl group (acceptor) to the N-terminal of poly-L-proline oligomers (1-12 proline residues) 61 These proline oligomers assume a trans helical conformation in ethanol and thus represent spacers of well-defined length (12-46 A). A continuous decrease in the transfer efficiency from 100% at a donor-acceptor separation of... 

The rate of EET between a pair of weakly coupled donor (D) and acceptor (A) molecules, according to Forster theory, [76] depends on the interchromophoric distance R, expressed in units of cm, their relative orientation (through the orientation factor k), and the spectral overlap I between donor emission and acceptor absorption spectra. The rate expression is ... 

The great success of Forster theory lies on the simplicity of these expressions, which can be applied from purely spectroscopic data. However, the approximations underlying these equations are not evident at first sight. It is better to turn to the Golden Rule expression of the rate ... 

In Forster theory, [76] the short-range term Vshort is neglected, and the Coulomb contribution is approximated as a dipole-dipole interaction between the transition dipole moments of D and A ... 

As introduced in Section 3.1, Forster theory assumes that there is no inhomogeneous line broadening, i.e. static disorder, in the spectra of donor emission and acceptor absorption. However, if one considers an ensemble of inhomoge-neously broadened spectra, the spectral overlap is given by ... 

The elucidation of the structure, dynamics and self assembly of biopolymers has been the subject of many experimental, theoretical and computational studies over the last several decades. [1, 2] More recently, powerful singlemolecule (SM) techniques have emerged which make it possible to explore those questions with an unprecedented level of detail. [3-55] SM fluorescence resonance energy transfer (FRET), [56-60] in particular, has been established as a unique probe of conformational structure and dynamics. [26-55] In those SM-FRET experiments, one measures the efficiency of energy transfer between a donor dye molecule and an acceptor dye molecule, which label specific sites of a macromolecule. The rate constant for FRET from donor to acceptor is assumed to be given by the Forster theory, namely [59,61-64]... 

In contrast, studies aiming at determining the exact nature of the non-radiative deactivation mechanism and the corresponding mean distance of interaction appear to be more in line with the Forster theory spirit and may be regarded as a fascinating attempt in this field. However, applications appear rather limited as far as the question of the hydration sphere determination is concerned. 

This relation was first obtained by Forster and is usually called the Forster theory. Rather than expressing W,-. y in the spectral-overlap relation, lT, y can be expressed in terms of the Franck-Condon factors which can be calculated from the potential surfaces as was done for the photo-induced ET or radiationless transitions. 

Forster theory [1] expresses the rate of EET from a donor D molecule (or atom) to an acceptor A in terms of the mutual orientation of the molecules, their center-to-center separation in units of cm, R, and the overlap, /, of the donor emission spectrum with the acceptor absorption spectrum, as shown in Figure 3.48. The Forster rate expression is... 

Extensions of EET theories to account for coherence in the rate expression [28-30] and complicated donor-acceptor aggregates [23-27] have been described in the literature. To understand the effect of the medium on the EET rate we need to focus on the electronic coupling component of the theory [11]. A primary assumption of Forster theory, relevant to the medium effect, is that the electronic coupling can be approximated as a dipole-dipole interaction between transition dipole moments of the donor and acceptor molecules,... 

In the first contribution, Huxter Scholes present a review of the recent evolution of theory of EET in condensed phase from their earliest and simple formulation, based on the Forster theory to the most recent advances of theoretical and computational methods based on continuum solvation models. In the second contribution, Curutchet reviews the recent developments of PCM towards accurate theoretical investigations of EET in solution. In particular, the modelization of the various contributions of solvent effects in the chromophore-chromophore electronic coupling is presented using quantum-mechanical approaches. 

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