Solvent-dependent fluorescence enhancement and piezochromism of a carbazole-substituted naphthopyran

• Published in: Journal of luminescence Vol. 165; pp. 159 - 166
• Main Authors: Liu, Lihui, Wang, Aixia, Wang, Guang, Munyentwari, Alexis, Zhou, Yihan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2015
• Subjects: Carbazole; Fluorescence; Naphthopyran; Photochromism; Piezochromism; solvent polarity; Piezochromism; Fluorescence; Naphthopyran; solvent polarity; Photochromism; Carbazole
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2015.04.026

A novel carbazole-substituted naphthopyran, 3,3-bis-(4-carbazolylphenyl)-[3H]-naphtho[2,1-b]pyran (CzNP) was designed and synthesized. The new compound exhibited normal photochromism in dichloromethane solution and the UV irradiation did not influence its fluorescence. On the contrary, the fluorescence of CzNP in N,N-dimethylformamide (DMF) was intensively enhanced to 29 times after 60min of the UV irradiation and this enhanced fluorescence can be quenched by addition of triethylamine (TEA). The study of enhanced extent of fluorescence of CzNP in solvents with different polarities and in mixed solvents demonstrated that the enhanced fluorescence is dependent on the polarity of solvents. The larger the polarity of solvent was, the stronger was the fluorescence of CzNP. CzNP also exhibited piezochromic performance and the pressure led to the cleavage of the C–O bond of pyran ring. •A carbazole-substituted photochromic naphthopyran was designed and synthesized.•The fluorescence was enhanced under the existence of DMF and UV irradiation.•The polarity of solvent was the dominating factor to affect the fluorescence.•The new compound also displayed piezochromic performance.