![]() The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv 0 / ), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν ν ) are investigated. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε s ≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. International Nuclear Information System (INIS)Īsim, Sadia Mansha, Asim Grampp, Günter Landgraf, Stephan Zahid, Muhammad Bhatti, Ijaz Ahmad Furthermore, analyze of solvent-solute interactions and value of ground and excited states dipole moments suggests different forms of resonance structures for Sudan dyes in polar and low- polar solvents.Įffect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents Obtained results express the effects of solvation on tautomerism and molecular configuration (geometry) of Sudan dyes in solvent media with different polarity. The solvatochromic behavior of these substances and their solvent-solute interactions were analyzed via solvent polarity parameters. The solvatochromic method was used to investigate dipole moments of these dyes in ground and excited states, in different media. N.Ībsorption and fluorescence spectra of three Sudan dyes (SudanIII, SudanIV and Sudan black B) were recorded in various solvents with different polarity in the range of 300-800 nm, at room temperature. Polar and low polar solvents media effect on dipole moments of some diazo Sudan dyes ![]()
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