Electronic excitation transfer in organized molecular assemblies

Resonance energy transfer: The unified theory revisited

“…RET is also observed in such diverse materials as levitated microdroplets, 35 lanthanide-doped lattices, 36 conjugated polymer chains 37 and both interlayer and intralayer transfer in Langmuir-Blodgett ͑LB͒ films [38][39][40] -and it has recently been linked with vibrational energy redistribution in water. 41 A wealth of diverse information can be ascertained from analysis of such processes; in LB-films alone, their study has afforded new insights into interlayer structures, 42,43 modified transfer dynamics in restricted geometries, 44,45 and both substrate 46,47 and micellar/surfactant effects. 48 Against the backdrop of intense research and development it is timely to revisit the theory which describes this fundamental pairwise ͑donor-acceptor͒ interaction.…”

100 and 50 years ago

“…Clusters of genes encoding proteins produced at similar stages in the parasite's life cycle, or proteins with similar functions, seem to be grouped in particular chromosomes or chromosomal locations. For example, in chromosome 2 there are many genes encoding proteins with high levels of the amino acid serine, and also genes encoding structures found on the surface of the parasite (merozoites) 2 . Another example of gene clustering is the sexual-stage-specific genes, which are localized to chromosome 5 in a related malaria parasite.…”

“…Solar energy is harvested by 'antenna' molecules that readily absorb photons of light, and is then transferred with great efficiency to a distant reaction site for use in metabolic processes. This transfer mechanism has been widely studied; it has even proved possible to mimic this aspect of photosynthesis in artificial lightharvesting structures based on molecular films 2 . Adopting this energy-transfer process in optoelectronics is an attractive idea that allows us to tailor the characteristics of a new generation of devices, such as polymer lightemitting diodes 3 and lasers 4 .…”

Reactions in lipid vesicles. Pyrene excimer formation in restricted geometries. Effect of temperature and concentration

“…Lipid vesicles provide a particular environment with low-dimensional geometry. The effects of dimensionality on chemical reactions are currently treated with kinetic models obtained from the theory of random walks in fractal domains (Takami and Mataga 1987;Yamazaki et al 1990;Kopelman 1986;Meakin and Stanley 1984;Argyrakis and Kopelman 1987;Lopez-Quintela et al 1987Lianos 1988;Lianos 1988, 1990). In the present work we employ fluorescence probing, by using the extensively studied fluorophore pyrene, to model the reaction A + B --+ products ([A] ~ [B]) in lipid vesicles.…”