A peroxo‐Mo(VI)/Mo(VI)‐mediated redox synthesis of quinazolin‐4(3H)‐ones and their aggregation‐induced emission property and mechanism

• Published in: Journal of physical organic chemistry Vol. 35; no. 5
• Main Authors: Chi, Mei, Xiong, Wu‐Lin, Yang, Dong‐Zhao, Fan, Cong‐Bin, Shi, Rong‐Wei, Gong, Shan‐Shan, Sun, Qi
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01.05.2022
• Subjects: Agglomeration; AIE mechanism; crystallographic analysis; Crystallography; Dehydrogenation; Emission; Lewis acid; Mathematical analysis; Phosphomolybdic acid; quinazolin‐4(3H)‐one; theoretical calculation
• ISSN: 0894-3230; 1099-1395
• DOI: 10.1002/poc.4329

An efficient method based on peroxo‐Mo(VI)/Mo(VI) redox cycle for ambient‐temperature synthesis of quinazolin‐4(3H)‐ones has been developed. Catalytic phosphomolybdic acid (PMA) exhibits Lewis acid and oxidative dehydrogenation activities at different phases of the reaction, and the true oxidative catalytic species was identified as peroxo‐Mo(VI) Keggin cluster. Surprisingly, we found that aggregation‐induced emission (AIE) is a generic property that has long been neglected for quinazolin‐4(3H)‐ones. Theoretical calculation results well rationalized their photophysical behaviors and elucidated their AIE mechanism as restriction of access to dark state (RADS). The crystallographic analysis of two representative quinazolin‐4(3H)‐ones not only revealed their packing mode and weak intermolecular actions but also supported the molecular conformations obtained by theoretical calculations. An efficient peroxo‐Mo(VI)/Mo(VI)‐mediated redox catalytic method for synthesis of the quinazolin‐4(3H)‐ones simply at ambient temperature has been developed. More importantly, we found that aggregation‐induced emission (AIE) is a generic property that has long been neglected for quinazolin‐4(3H)‐ones. Theoretical calculations well rationalized their photophysical behaviors and elucidated their AIE mechanism as restriction of access to dark state. Single crystal data of two representative quinazolin‐4(3H)‐ones well supported the molecular conformations and AIE mechanism obtained by theoretical calculations.