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Environment‐Sensitive Behavior of DCNP in Solvents with Different Viscosity, Polarity and Proticity
Author(s) -
Morawski Olaf,
Kozankiewicz Boleslaw,
Miniewicz Andrzej,
Sobolewski Andrzej L.
Publication year - 2015
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201500563
Subject(s) - chemistry , solvent , nanosecond , viscosity , photochemistry , fluorescence , fluorescence spectroscopy , isomerization , time resolved spectroscopy , quantum yield , yield (engineering) , polarity (international relations) , spectroscopy , solvent effects , polar , derivative (finance) , molecule , organic chemistry , thermodynamics , optics , laser , biochemistry , astronomy , financial economics , economics , physics , quantum mechanics , cell , catalysis
A pyrazoline derivative, 3‐(1,1‐dicyanoethenyl)‐1‐phenyl‐4,5‐dihydro‐1H‐pyrazole (DCNP), is studied by using optical spectroscopy methods in several solvents at room and at low temperatures. The DCNP molecule reveals a complex photophysics behavior, which is sensitive to solvent polarity, proticity, temperature and viscosity and arises from the presence of two rotational degrees of freedom of the dicyanovinyl group—the torsion around the double C=C bond and the s‐trans – s‐cis isomerization around the single C−C bond—that differently behave in various environmental conditions. The fluorescence yield of a few percent and sub‐nanosecond decay times observed at room temperature make the compound useful for optical studies of liquid environments. The proticity of polar solvents can be detected with two‐exponential fluorescence decays. At low temperatures, DCNP can be used as solvent viscosity or temperature fluorescent sensor.