Fluoroponytailed Brooker's merocyanines: Studies on solution behavior, solvatochromism and supramolecular aggregation

In this investigation, influences on solution behavior and solvatochromism caused by the attachment of a 1H,1H,2H,2H-perfluorooctyl side chain onto derivatives well-known Brooker's Merocyanine (BM) chromophore are explored. Starting from either 4-picoline or 2-picoline, corresponding polyfluoroalkylated o- p-BM have been synthesized in three steps. For all dyes, UV–Vis measurements were conducted 21 different solvents. An attempted analysis solvatochromic properties applying linear fits according to Kamlet-Taft parameters turned out be partially inconclusive was only feasible for five novel dyes after careful examination their spectra. The observed changes spectral characteristics, combination with occurrence strong hypsochromic bathochromic shifts, too significant ascribable influence solvating medium. Additionally, maxima solvents exposed tendencies converge at specific wavelengths. Taking into account that both, merocyanines as well fluorosurfactants known formation supramolecular assemblies, we suggest aggregation is responsible phenomena, although controversially disputed preliminary literature concerning BM. To underline our proposal, concentration dependent supplemented.