A recently reported protolytic gating effect on the ring closing reaction of an oligo(phenylene ethynylene) (OPE) embedded difurylperfluorocyclopentene (S) with a dimethylaminophenyl chain link in each of the side arms, was quantitatively analyzed in detail. The reaction system (So, SoH(+), SoH2(2+), Sc, ScH(+), ScH2(2+)) comprising three protolytic forms in both open and closed configuration, ...

We have measured the radical pair quantum yield of reaction centers of photosystem II of green plants and of the purple bacterium Rhodobacter sphaeroides as a function of excitation density using sub-picosecond pulses at 77 K. The saturation behavior of both RCs can be described consistently by taking into account stimulated emission and the geometry of the polarized (magic angle) laser experim...

Water-soluble fluorescent gold clusters (AuCs) have been successfully synthesized by a wet-chemical approach at room temperature using a dipeptide l-cysteinyl-l-cysteine. We have followed the core-etching mechanism for the synthesis of the gold clusters. Clusters show the excitation maximum at 300 nm and the emission maximum at 410 nm. These gold clusters show interesting fluorescent properties...

We have examined the photophysics of energy migration and trapping in photosystem I by investigating the spectral and temporal properties of the fluorescence from the core antenna chlorophylls as a function of the antenna size. Time-correlated single photon counting was used to determine the fluorescence lifetimes in the isolated P700 chlorophyll a-protein complex and in a mutant of Chlamydomon...

ABSTRACT: This work aimed to evaluate changes in gas exchanges and chlorophyll a fluorescence fig plants due the film formed on leaf surface by Bordeaux mixture applied control rust. The experiment was conducted an orchard with 7-month-old trees of cultivar Roxo de Valinhos, April 2020. A completely randomized experimental design four replications used, consisting two treatments (with without a...

When bleached, aerobically grown cells of Rhodopseudornonas spheroides are transferred to semi-aerobic conditions to induce bacteriochlorophyll synthesis, a new fluorescence band, with a maximum at 790 nm, is observed in addition to the 885 nm emission maximum normally seen in pigmented cells. The 790 nm fluorescence may be due to bacteriochlorophyll which has not been bound into the chromatoph...

Pink Petuniahybrida (cv Hit Parade Rosa) corollas were found to contain photosynthetically active chloroplasts. The corolla chloroplasts were similar to those of green leaves in size and structure. The chlorophyll (Chl) content of Petunia corollas increased during early stages of flower development, reaching a maximum just before anthesis. Chloroplasts isolated from corollas at this stage, carr...

In this study, the impact of future climate change on photosynthetic efficiency as well as energy partitioning in the Stipa bungeana was investigated by using chlorophyll fluorescence imaging (CFI) technique. Two thermal regimes (room temperature, T0: 23.0/17.0°C; High temperature, T6: 29.0/23.0°C) and three water conditions (Control, W0; Water deficit, W-30; excess precipitation, W+30) were se...