Über Pyridinium‐ N ‐phenolat‐Betaine und ihre Verwendung zur Charakterisierung der Polarität von Lösungsmitteln, XIV. Versuche zur Herstellung eines chiro‐solvatochromen Pyridinium‐ N ‐phenolat‐Betainfarbstoffs

Pyridinium N ‐Phenoxide Betaines and Their Application for the Characterization of Solvent Polarities, XIV. — Attempted Synthesis of a Chiro‐Solvatochromic Pyridinium N ‐Phenoxide Betaine Dye Synthesis and UV/VIS spectroscopic properties of the negatively solvatochromic, chiral, ( S , S )‐configurated betaine dye 8 are described. There is a linear correlation between the E T′ values of 8 and the E T ( 30 ) values of the standard betaine dye 1 (Figure 1). Unfortunately, ( S , S )‐ 8 , dissolved in enantiomeric pure ( R )‐ and ( S )‐configurated alcohols and amines, does not show a measurable chiro‐solvatochromism (Table 2).