Photophysical processes of merocyanine 540 (MC540) are studied using picosecond time-resolved emission spectroscopy. The nonradiative rate of MC540 increases from 0.32 × 109 s-1 in dioxane to 8.73 × 109 s-1 in water, i.e., nearly 27 times. This is attributed to the decrease in the barrier of photoisomerization with increase in polarity and the consequent increase in the rate of photoisomerizati...

Photodynamic inactivation of Staphylococcus aureus planktonic and biofilm cells by a phtotosensitizer, merocyanine 540 (MC 540), was investigated. For the planktonic experiments, MC 540 binding efficiency to bacterial cells was found to increase with both increasing MC 540 concentration and increasing incubation time, but the binding became saturated following 10 min of incubation. The antimicr...

Detailed kinetic investigations of the most common photoswitchable spiropyran, 6-nitro-BIPS, reveal that hydrolytic decomposition of its merocyanine isomer limits its utility in aqueous buffer; however, simple replacement of the 6-nitro substituent with an 8-carboxylate yields a BIPS photoswitch that is potentially better suited for biological applications.

Light transmission changes upon massive stimulation of single muscle fibers of Xenopus were studied with the potential-sensitive nonpermeant dyes, merocyanine rhodanine (WW375) and merocyanine oxazolone (NK2367). Upon stimulation an absorption change (wave a) occurred, which probably represents the sum of action potentials in the transverse tubules and surface membrane. In WW375-stained fibers ...

Photochromic spiropyrans modified with fluorophores were investigated as molecular platforms for the achievement of fluorescence switching through modulation of energy transfer. The dyads were designed in such a way that energy transfer is only observed for the open forms of the photochrome (merocyanine and protonated merocyanine), whereas the closed spiropyran is inactive as an energy acceptor...

The absorption and fluorescence properties of a barbiturate-type donor-pi-acceptor (D-pi-A) merocyanine dye are controlled by complexation with dimeric melamine receptors featuring different tether lengths.

Merocyanine (MC) isomers that are formed after absorption of a UV photon by 1',3'-dihydro-1',3'-3'-trimethyl-6-nitrospiro[2H-1-benzopyran-2',2'-(2H)-indole] were studied. Several, predominantly TTC and TTT, merocyanine isomers are present in toluene solution ("T" and "C" indicate trans and cis conformations of the C-C bonds in the methine bridge). Excitation in the MC visible absorption band (a...