Negative solvatochromism of merocyanine dyes: Application as water content probes for organic solvents

Synthesis, Solvatochromic Performance, pH Sensing, Dyeing Ability, and Antimicrobial Activity of Novel Hydrazone Dyestuffs

“…Generally, a solvatochromic material can be defined as a chemical substance able to alter its color in solvents of different polarities due to a variation in its absorption or emission spectra in each solvent. ere is a variety of solvatochromic dyes that have been discovered recently, such as pyridinium, merocyanine, and stilbazolium dyes [9][10][11][12][13][14][15].…”

The application of 7H-indolo[1,2-a]quinolinium merocyanine as a new water sensor in organic solvents

“…Moreover, this method requires ex situ analysis, indicating its incapacity for real-time monitoring. Other methods which allow to determine the water in liquid and solid samples include gas chromatography (Iguchi et al 1988 ; Nubbaum et al 2000 ), liquid chromatography (Chen and Fritz 1989 ), infrared spectroscopy (Tran and Grishko 2004 ; Troshin et al 2008 ; Bampi et al 2013 ), refractometric method (Sanchez et al 2010 ), microwave accelerated Dean–Stark method (Villet et al 2009 ), electrochemical method (Gąsiorowska et al 2009 ), as well as absorption and fluorescence spectroscopy (Bai and Yang 2007 ; Cha et al 2011 ; Rahimi-Nasrabadi et al 2015 ; Shen et al 2016 ). Recently, the development of highly sensitive fluorescent and colorimetric molecular sensors seems to have great meaning.…”

“…These sensors make possible in situ analysis of water content in organic solvents with high sensitivity and precision and low detection limits. Their applicability in water determination results from the fact that the addition of water into an organic solvent leads to the changes in intensities of their emission or absorption spectra and/or the spectral shifts of the sensors (Langhals 1990 ; Pinheiro et al 2006 ; Cha et al 2011 ; Rananaware et al 2015a , b ; Jung et al 2016 ). Some examples of these compounds, as well as the mechanism of their action have been freshly described by Jung et al ( 2016 ).…”

“…As a consequence, in UV–Vis absorption spectra of a solvatochromic probe, a hypsochromic or bathochromic shift can be noticed. In most cases, the plot describing the relation between the position of the solvatochromic band maximum and the amount of water in an organic solvent is not linear in the whole range of water concentration (Langhals 1990 ; da Silva et al 2002 ; Pinheiro et al 2006 ; Cha et al 2011 ). The deviation from the linearity can be explained in terms of the preferential solvation of the solute S (the solvatochromic probe) by one of the components of binary water–organic solvent mixtures.…”

Signaling of water content in organic solvents by solvatochromism of a hydroxynaphthalimide-based merocyanine dye

“…The development of sensors based on fluorescent conjugated poly(m-aminobenzoic acid) [13], europium ternary complexes immobilized on glass surfaces [14], and acridine orange-based optical fiber [15] is also noteworthy. On the other hand, colorimetric sensors based on merocyanine dyes, such as various isomers of 4-[(4 0 -oxocyclohexa-2 0 ,5 0 -dienylidene)ethylidene]-1,4-dihydropyridine [16,17] and hydroxycoumarin derived dyes [18], and using their unique solvatochromism have been reported. In addition to these, other sensitive sensors derived from various unique materials such as europium-based luminescent nanospheres [19] and a turn-on-type luminescent flexible Mg 2þ metal-organic framework [20] have also been developed.…”