Room Temperature Phosphorescence from Organic Materials: Unravelling the Emissive Behaviour of Chloro‐Substituted Derivatives of Cyclic Triimidazole. Issue 13 (6th April 2021)

• Record Type: Journal Article
• Authors: Giannini, Clelia; Forni, Alessandra; Malpicci, Daniele; Lucenti, Elena; Marinotto, Daniele; Previtali, Andrea; Carlucci, Lucia; Cariati, Elena
• Is Part Of: European journal of organic chemistry. Issue 13(2021)
• Page Start: 2041
• Page End: 2049
• Publication Date: 2021-04-06
• Subjects: Aggregation induced emission -- DFT and TDDFT calculations -- Mild chlorination -- Organic materials -- Phosphorescence; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.202100131
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: Purely organic luminophores that exhibit room temperature phosphorescence (RTP) are receiving an ever‐growing attention. The design of efficient RTP materials and the understanding of their emissive behaviour, however, remain a challenging task. Herein, to gain further insights into metal‐free RTP, we report the synthesis, characterization, and photophysical study of chloro‐derivatives of [1, 2‐ a :1′, 2′‐ c :1′′, 2′′‐ e ][1, 3, 5]triazine or cyclic triimidazole (TT ). Mono‐ (1Cl ), di‐ (2Cl ) and tri‐chloro‐TT (3Cl ) derivatives are prepared by mild chlorination with N ‐chlorosuccinimide (NCS). The three compounds are characterized by aggregation‐induced emission (AIE) comprising dual fluorescence and multiple phosphorescences, whose origin is disclosed by crystal structure analysis together with accurate DFT/TDDFT calculations. Comparison with previously reported bromine and iodine TT derivatives reveals the new chlorinated compounds as the best performing halogenated AIE members of the family. Abstract : Mild chlorination of cyclic triimidazole with N ‐chlorosuccinimide affords the new mono‐, di‐ and tri‐chloro‐derivatives characterized by aggregation‐induced emission comprising dual fluorescence and multiple phosphorescences. The origin of the emissive behavior of these compounds is analyzed by means of DFT/TDDFT calculations, crystal structure analysis, and comparison with previously reported members of this family.