Figure 1

Solvatochromism in Merocyanine dye, HB194. (a) Molecular structure of Merocyanine dye (HB194); (b) solvents used in this study to understand the solvatochromic behaviour of the dye; (c) absorption (solid lines) and fluorescence spectra (dashed lines) of HB194 in different solvents. The absorption spectra of HB194 solutions are shown in optical density (OD) unit, which are used for transient absorption studies. The fluorescence spectra are obtained after subjecting the sample solutions to excitation at 530 nm and then the spectra are normalized for comparison. The solvatochromic behaviour can clearly be seen from fluorescence spectra with an anomalously red-shifted spectrum in EG. Based on these steady state measurements, HB194 solutions are categorized into four different groups: HB194 (CYH), HB194 (THF, DCM), HB194 (DMK, MeCN) and HB194 (EG).