Exploring the Förster limit in a small FRET pair

Evidence for reverse pathways and equilibrium in singlet energy transfers between an artificial special pair and an antenna

“…So, this qualitative relationship between MO couplings and rates still are correlated, but these MO computations do not address the thermal dependence. This observation reinforces what Scholes and collaborators concluded about the Forster's theory, including its inability to deal with the temperature as the thermal activation parameter is not taken into account in the analysis [38][39][40][41].…”

“…The portion that includes the ratio of integrals is called the normalized J-integral and relates the fraction of the donor fluorescence that overlaps the absorption of the acceptor. Despite numerous recent reports indicating that this theory is an approximation with limited precision for short distances for r, the basis of the principle is still valid and this approach is a reasonable starting point [38][39][40][41]. This spectral overlap using compounds 2 and 3 shows that both chromophores can indeed act as energy donors and acceptors (Fig.…”

Using a Photoacid Generator to Switch the Direction of Electronic Energy Transfer in a Molecular Triad

“…In this case, EET might be expected from the blue dye inside the zone to green dye at the periphery of the acidified region. The Fçrster critical distance computed [21] for such EETs is approximately 30 and; with state-of-the-art confocal microscopy, the diameter of the zone could be decreased to approximately 100 nm. The effect of bimolecular EET under such conditions would be a small reduction in the apparent dimensions of the activated zone when measured by fluorescence microscopy.…”

“…The net result is that only the green dye emits in the film, regardless of the excitation wavelength. At high loading of B(DPP)G, energy migration among molecules of the green dye will disperse the electronic energy since the intermolecular Fçrster critical distance computed [21] for random orientations of B(DPP)G is approx- imately 35 . On loading the B(DPP)G-doped film (20 mg mL À1 initial solution) with PAG (1 mg mL À1 of solution prior to spin-coating), the EET step remains unaffected but fluorescence from the green dye is decreased by approximately 40 % relative to a film prepared in the absence of PAG because of intermolecular electron transfer.…”

On the interactions between molecules in an off-resonant laser beam: Evaluating the response to energy migration and optically induced pair forces

“…[4][5][6][7] The phenomenon also has an important function in the operation of organic light-emitting diodes and luminescence detectors. 8,9 In the realm of molecular biology, the determination of protein structures and the characterization of dynamical processes are furthered by studies of the transfer of energy between chromophores; [10][11][12] several ultrasensitive molecular imaging applications are again based on the same underlying principle. [13][14][15][16][17] The migration of electronic excitation between molecular units, central to each such application, has received extensive experimental and theoretical study.…”