Synthesis, properties and quantum chemical evaluation of solvatochromic pyridinium-phenyl-1,3-thiazol-4-olate betaine dyes
作者:Roberto Menzel、Stephan Kupfer、Ralf Mede、Helmar Görls、Leticia González、Rainer Beckert
DOI:10.1016/j.tet.2012.12.016
日期:2013.2
The syntheses and characterizations of four zwitterionic betaines are presented. These dyes possess an uncommon heterocyclic 1,3-thiazol-4-olate donor moiety. The natures of the HOMO/LUMO transitions and of the intramolecular charge-transfer state were assigned with the help of quantum chemical calculations. Multiple intermolecular solute/solvent interactions were discussed using linear solvation energy relationship (LSER) with Kamlet-Taft and Catalan parameters. The dyes show a pronounced negative solvatochromism ranging from lambda(max) 392 nm in TFE to 820 nm in THF (Delta lambda=428 nm or 1.65 eV). The X-ray structures of one of the tetrafluoroborate salts and of one of the betaines are discussed. (c) 2013 Elsevier Ltd. All rights reserved.