A new solvatochromic linear π-conjugated dye based on phenylene(poly)ethynylene as supersensitive low-level water detector in organic solvents

A novel class of phenylene-(poly)ethynylene-based dye Sensor 1 with remarkable properties of solvatochromism has been designed and synthesized. A long, coplanar and asymmetry electron-rich pi-conjugated structure endows Sensor 1 with maximum solvatochromic effect by intramolecular charge-transferstates (ICT). More importantly, The dye is found to serve as supersensitive fluorescent indicator for the quantitative detection of low-level water content in five common organic solvents with low detection limits. Furthermore, the development of easy-to-prepare test papers provides a convenient and reliable approach to qualitatively monitor water in organic solvents by naked eye. Results in this work not only provide a successful molecular design concept of the novel sensitive solvatochromic dye sensor for water in organic solvents, but also develop practical applications of the linear pi-conjugated molecule bearing phenylene-(poly)ethynylene in chemosensor field. (C) 2016 Elsevier Ltd. All rights reserved.