1628-58-6Relevant articles and documents
Bimolecular fluorescence quenching of benzoxazole/benzothiazole-based functional dyes
Balcerak, Alicja,Kabatc, Janina
, (2020/06/18)
Four dyes that belong to the group of hemicyanines and possess benzoxazole and benzothiazole moieties are synthesised and described. The spectroscopic properties of these compounds in 1-methyl-2-pyrrolidinone (MP) were studied. Synthesised dyes absorb in the UV–Vis region. The emission spectra are broad with a maximum located at approximately 500–520 nm. The deactivation of excited states of the synthesised molecules by various quenchers is also presented. The fluorescence quenching parameters were calculated using the Stern-Volmer equation. It was found, that the fluorescence quenching of the excited dye by quencher molecules occurs. The fluorescence quenching rates (kq) are about 1010 M?1 × s?1.
Photoisomerization of trans-2-[4′-(dimethylamino)styryl]benzothiazole
Mishra, Anasuya,Thangamani, Arumugam,Chatterjee, Soumya,Chipem, Francis A. S.,Krishnamoorthy, Govindarajan
, p. 247 - 252 (2013/03/13)
Photoreaction of trans-2-[4′-(dimethylamino)styryl]benzothiazole (t-DMASBT) under direct irradiation has been investigated in dioxane, chloroform, methanol and glycerol to understand the mechanism of photoisomerization. Contrary to an earlier report, isomerization takes place in all these solvents including glycerol. The results show that restriction on photoisomerization leads to the increase in fluorescence quantum yield in glycerol. The results are consistent with the theoretically simulated potential energy surface reported earlier using time-dependent density functional theory (TDDFT) calculations. DFT calculations on cis isomers under isolated condition have suggested that cis-B conformer is more stable than cis-A conformer due to hydrogen-bonding interaction. In the ground state, cis-DMASBT is predominantly present as cis-B. The fluorescence spectra of the irradiated t-DMASBT suggested that photoisomerization follows not the adiabatic path as proposed by Saha et al., but the nonadiabatic path. Contrary to an earlier report, the photoisomerization of trans-2-[4′-(dimethylamino)styryl]benzothiazole occurs in all the solvents including viscous glycerol and it follows not the adiabatic, but the non-adiabatic path. Relative higher fluorescence quantum yield obtained in glycerol is due to restriction on photoisomerization. 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology
Utilities of olefin derivatives
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Page/Page column 22; 32, (2008/06/13)
Compounds having an activity to enhance the expression of apoAI are provided. Compounds of formula (I): in which Ar1 and Ar2 are independently a phenyl, naphthyl, or monocyclic or bicyclic aromatic heterocyclic group, which may be optionally substituted; —X— is —N═CZ2-, —CY2═CZ2-, —CY2Y3—CHZ2-, —S—, —O—, or the like; Y1, Y2, Y3, Z1 and Z2 are independently a hydrogen, a halogen, a lower alkyl, a phenyl, or the like; Z1 and Z2 may be independently a linker group that may combine with Ar2 and Ar1 to form a condensed ring; m is 0 or 1, and n is 0 to 2; a prodrug thereof, a pharmaceutically acceptable salt or solvate of them; are disclosed.
