Solvatochromic Solvent Polarity Measurements In Analytical Chemistry: Synthesiss And Applications Of Et-30

Abstract
The ET(30) scale of solvent polarity has been shown to be useful in examining many diverse analytical processes. It is based on the charge transfer absorption of 2,6-diphenyl-4-(2,4,6-triphenyl-N-pyridinio)phenolate (referred to as ET-30 in this paper). Unfortunately, use of the ET(30) scale has been hindered by (a) the lack of a commercial source of the ET-30 dye and (b) the lack of an English language synthetic procedure. Here we discuss recent applications of the ET(30) scale to analytical techniques, as well as a simplified procedure for the synthesis of ET-30.