
%0 Journal Article
%A Kipkemboi, PK 
%A Easteal, AJ 
%T Solvent Polarity Studies of the Water+t-Butyl Alcohol and Water+t-Butylamine Binary Systems With the Solvatochromic Dyes Nile Red and Pyridinium-N-phenoxide Betaine, Refractometry and Permittivity Measurements
%J Australian Journal of Chemistry
%D 1994/09/01
%V 47
%N 9
%P 1771-1781
%K 
%R https://doi.org/10.1071/CH9941771
%U https://www.publish.csiro.au/paper/CH9941771 
%X The empirical solvent polarity parameters ENR and ET for the solvatochromic compounds Nile Red (1) and pyridinium-N-phenoxide betaine (2), respectively, have been determined as a function of composition for water+t -butyl alcohol and water+t-butylamine binary mixtures, over the whole composition range at 298 K. For both systems the two parameters vary with composition in a strongly non-linear fashion, and the polarity of the mixture decreases with increasing proportion of the organic cosolvent. The non-linear variation of the polarity parameters is attributed to water-cosolvent hydrophobic interactions at low cosolvent contents, and hydrogen-bonding interactions at higher cosolvent contents. Permittivity and refractive index have also been measured at 298 K for both systems, and both properties are strongly non-linear functions of composition. 
