Aromatic Amides: A Smart Backbone toward Isolated Ultralong Bright Blue-Phosphorescence in Confined Polymeric Films.
Angew Chem Int Ed Engl 2023;
62:e202300927. [PMID:
36862068 DOI:
10.1002/anie.202300927]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/25/2023] [Accepted: 03/01/2023] [Indexed: 03/03/2023]
Abstract
Represented herein is heavy-atom-free aromatic amides enabling population of 3(п,п*) configuration for bright long-lived blue phosphorescence. Isolated inherent deep-blue (0.155, 0.056) to sky-blue (0.175, 0.232) phosphorescence with high quantum yield (up to 34.7%) in confined films are achieved. Spectroscopic study and theoretical calculation demonstrated the strong spin-orbit coupling of 1(п,п*)/3(n,п*) and 1(n,п*)/3(п,п*) states within the aromatic amides (4-ethoxy-N-(pyridin-4-yl)benzamide (P1), 3,4-dimethoxy-N-(yridine-4-yl)benzamide (P2), 4-(dimethylamino)-N-(pyridin-4-yl)benzamide (P3)), as well as the robust hydrogen bonding with polyvinyl alcohol to suppress vibrational relaxation and stacking-induced quenching. The blue afterglow films can last for several seconds showcasing in information display, anti-counterfeiting and white light afterglow. The high population of emissive 3(п,п*) states and facile accessibility of aromatic amide skeleton provide an important molecular design prototype to manipulate triplet excited states for ultralong phosphorescence at blue and other regions.
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