Liquid azo dyes

Survey, fluorescence spectra, and solubility of liquid cyanine dyes

“…Recently, we serendipitously discovered several neutral-type liquid dyes, coumarins, 13 (dialkylamino)perfluorophenazines, 14 and azo compounds. 15 Recently, much attention has been paid to ionic liquids, whose chemical structures consist of heteroaromatic cations and anions. They are used as reaction solvents, [16][17][18][19][20][21][22][23][24][25][26] electrolytes for secondary batteries [27][28][29][30] and in dye-sensitised solar cells.…”

Cold Crystallization and Polymorphism Triggered by the Mobility of the Phenyl Group in Alkyl Azo Dye Molecules

“…In the field of dyes and pigments, azo molecules are known to exhibit cold crystallization. 24,25 In this study, the alkyl derivatives of Sudan III (SD3-OCn, n = alkyl chain length; Figure 1), which is a red dye molecule possessing two azo groups and rotatable π-planes, exhibited a fascinating thermal behavior, including cold crystallization. SD3-OCn exhibits two types of molecular structures when both azo groups adopt a trans conformation.…”

“…The alkylation of small molecules possessing π-planes is a promising strategy to induce cold crystallization. − The assembled molecular structures and crystallization behavior are controlled by the alkyl chains according to their chain lengths. − Conversely, the π-planes may be assembled into stack structures because of the π–π interactions. − In previous studies, Schiff base compounds, Schiff base metal complexes, and alkylated diketopyrrolopyrrole (DPP) pigment molecules exhibited cold crystallization. ,,, It was suggested that the mobility of the π-plane could trigger supercooling, although clearer evidence is still required. In the field of dyes and pigments, azo molecules are known to exhibit cold crystallization. , In this study, the alkyl derivatives of Sudan III (SD3-OC n , n = alkyl chain length; Figure ), which is a red dye molecule possessing two azo groups and rotatable π-planes, exhibited a fascinating thermal behavior, including cold crystallization. SD3-OC n exhibits two types of molecular structures when both azo groups adopt a trans conformation.…”

Synthesis and properties of liquid pyrazine dyes

“…The syntheses of liquid dyes have been reported for several dye systems including coumarins [8], perfluorophenazines [9], fullerenes [10], and azo compounds [11] with various substituents such as linear or branched dialkylamino, alkoxy, and alkyl groups. In previous reports, the melting points of functionalised organic dyes have been shown to decrease with long flexible chain substituents, sometimes becoming viscous oils or fluids at room temperature.…”