We have investigated the kinetic and thermodynamic parameters of thermal reversion of the spirooxazine 1,3,3-trimethyl-5'-(2-benzothiazolyl)-spiroindoline-2,3'-naphtho(2,1-b)(1,4) oxazine (SO) in molecular solvents and ionic liquids containing the [NTf2]- anion. E(T)30 and Kamlet-Taft parameter studies were employed to interpret IL polarity and attempt to rationalise the kinetic-polarity relati...

The polarity of biological mediums controls a host of physiological processes such as digestion, signaling, transportation, metabolism, and excretion. With the recent widespread use of near-infrared (NIR) fluorescent dyes for biological imaging of cells and living organisms, reporting medium polarity with these dyes would provide invaluable functional information in addition to conventional opt...

The photophysical properties of 2-phenyl-naphtho[1,2-d][1,3]oxazole, 2(4-N,N-dimethylaminophenyl)naphtho[1,2-d][1,3]oxazole and 2(4-N,N-diphenylaminophenyl) naphtho[1,2-d][1,3]oxazole were studied in a series of solvents. UV-Vis absorption spectra are insensitive to solvent polarity whereas the fluorescence spectra in the same solvent set show an important solvatochromic effect leading to large...

We have developed a multi-array side-polished optical-fiber gas sensor for the detection of volatile organic compound (VOC) gases. The side-polished optical-fiber coupled with a polymer planar waveguide (PWG) provides high sensitivity to alterations in refractive index. The PWG was fabricated by coating a solvatochromic dye with poly(vinylpyrrolidone). To confirm the effectiveness of the sensor...

Abstract A series of novel substituted-azo dyes 8-(aryldiazenyl)quinolin-5-ol (5a-i) were synthesized by the coupling reaction 5-hydroxyquinoline with diazotized aniline derivatives in presence NaNO2 HCl/H2O mixture. The study spectroscopic and solvatochromic properties performed FT-IR, 1H 13C-NMR UV-Visible spectroscopies. tautomerism these was studied using deuteration technique measurements....

We describe the design, synthesis and fluorescent profile of a family of environment-sensitive dyes in which a dimethylamino (donor) group is conjugated to a cyanoacrylate (acceptor) unit via a cyclopenta[b]naphthalene ring system. This assembly satisfies the typical D-π-A motif of a fluorescent molecular rotor and exhibits solvatochromic and viscosity-sensitive fluorescence emission. The centr...