Linear solvation energy relationships. Part 31. On Bekárek's modifications of the solvatochromic parameters

Abstract

Bekárek has proposed that the solvatochromic parameters, π*, and α, and β, be modified to give π_n*=π*/f (n²), α_n=α/f (n²), β_n=β/f (n²), where f (n²)=(n²– 1)/(2n²+ 1), and has suggested that, while the former parameter set is adequate to correlate some types of electronic spectral properties, the latter set is to be preferred for correlating most other type properties. It is shown that π*andπ_n* correspond to single, unique dipolarity–polarizability blends the solvent effects, and that the (π*+dδ) formalism is in better suited to correlate effects involving the full range of possible dipolarity–polarizability blends in the solute–solvent interactions.