N-aryl-4-amino-1,8-naphthalimide Tröger's bases-based internal charge transfer (ICT) fluorescence ‘turn-on’ chemosensors for volatile organic amines

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2023-07, Vol.441, p.114727, Article 114727
• Main Authors: Mohan, Binduja, Sarkar, Dipanjana, Raja Lakshmi, Pandi, Umadevi, Deivasigamani, Shanmugaraju, Sankarasekaran
• Format: Article
• Language: English
• Subjects: 8-naphthalimide; Amino-1; Benzylamine sensor; Fluorescence sensors; Tröger’s base; Volatile organic amines
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2023.114727

Two cleft-shaped N-aryl-4-amino-1,8-naphthalimide Tröger’s bases have been designed and employed as fluorescent ‘turn-on’ and colorimetric chemosensors for the discriminative sensing of volatile organic amines with high selectivity for benzylamine. [Display omitted] •Two ‘cleft-shaped’ N-aryl-4-amino-1,8-naphthalimide derived Tröger's bases (TBNap-Ph and TBNap-Es) have been designed and used as fluorescence sensors for discriminative sensing of volatile organic amines (VOAs).•Both TBNap-Ph and TBNap-Es displayed discriminative fluorescence sensing characteristics for various VOAs with high selectivity for benzylamine.•TBNap-Ph and TBNap-Es can detect benzylamine at ppm level of sensitivity.•The experimentally observed discriminative sensing results were validated by computational calculations. The design of reliable sensor systems for quick sensing and monitoring the trace concentrations of volatile organic compounds (VOCs) has been a topical area of research in recent years due to their serious menace to living systems and environmental hazardousness. In this article, we report two unique ‘cleft-shaped’ N-aryl-4-amino-1,8-naphthalimide derived Tröger's bases (TBNap-Ph and TBNap-Es) as efficient, fast fluorescence sensors for discriminative sensing of volatile organic amines (VOAs). The fluorescence titration studies using TBNap-Ph and TBNap-Es demonstrated discriminative fluorescence sensing responses for VOAs with high selectivity for benzylamine detection. The initial emission intensity of TBNap-Ph and TBNap-Es was enhanced drastically upon the addition of benzylamine. However, similar titration studies using other VOAs such as n-propylamine, n-butylamine, diethylamine, isopropylamine, 3-dimethylamino-1-propylamine, triethylamine, and ethanolamine elicited poor to negligible changes in the fluorescence emission intensity. The selective ‘turn-on’ fluorescence sensing of benzylamine was also reflected by sharp color changes and these sensors can be used to detect benzylamine at the parts-per-millions (ppm) level of sensitivity. Furthermore, the experimentally observed discriminative fluorescence sensing property of TBNap-Ph and TBNap-Es towards VOAs was supported by computational calculations.