Influence of solvent polarity and medium acidity on the UV-Vis spectral behavior of 1-methyl-4-[4-amino-styryl] pyridinum iodide.
Electronic absorption, and excitation spectra of 1-methyl-4-[4-aminostyryl] pyridinum iodide (M-NH2) were measured in solvents of different polarity. The (M-NH2) dye exhibits negative solvatochromism, i.e. a hypsochromic band shift as the solvent polarity increases. The fluorescence quantum yield is also sensitive to the polarity and viscosity of the medium. The ground and excited state protonation constants were calculated and amount to 3.35 and 0.62, respectively. The effect of micellization on the emission spectrum of (M-NH2) are also studied in sodium dodecyl sulphate (SDS). The fluorescence intensity increases as the concentration of SDS increases with an abrupt change at cmc. The quantum yield of the cis trans photoisomerization is also determined in aqueous buffer solution of pH 1.1.
el-Daly
Samy A
SA
Chemistry Department, Faculty of Science, Tanta University, Tanta Egypt.
Abdel-Kader
Mahmoud H
MH
Issa
Raafat M
RM
el-Sherbini
el-Sayed A
el-SA
D006863:Hydrogen-Ion Concentration; D008027:Light; D008823:Micelles; D008956:Models, Chemical; D015233:Models, Statistical; D011726:Pyridinium Compounds / Q000032:analysis / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D012997:Solvents; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry / Q000379:methods*; D014466:Ultraviolet Rays
C475681:1-methyl-4-(4-aminostyryl)pyridinium; D008823:Micelles; D011726:Pyridinium Compounds; D012997:Solvents; D012967:Sodium Dodecyl Sulfate