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Room Temperature Phosphorescent (RTP) N‐Acetylphenothiazines
Author(s) -
Sarkar Tanmay Kumar,
Sarkar Samir Kumar,
Thilagar Pakkirisamy
Publication year - 2020
Publication title -
chemphotochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.13
H-Index - 18
ISSN - 2367-0932
DOI - 10.1002/cptc.201900296
Subject(s) - phosphorescence , intersystem crossing , excited state , photochemistry , acceptor , chemistry , triplet state , moiety , substituent , molecule , fluorescence , singlet state , stereochemistry , atomic physics , physics , organic chemistry , optics , condensed matter physics
Herein we disclose a series of purely organic molecules ( 1 – 4 ) with a donor‐acceptor architecture (phenothiazine donor (D) and the acyl acceptor (A)) exhibiting room temperature dual phosphorescence (RTDP) characteristics. Detailed computational and photophysical studies revealed that the dual RTP bands with different wavelengths and lifetimes in these compounds originate from excited triplet states of different energies. In particular, the electronic nature of the substituent on the acceptor acyl unit has a significant effect on the energy of the ICT state, hybridization of excited states, as well as the rate of intersystem crossing. Compound 1 with an electron‐deficient CF 3 −CO acceptor moiety exhibit RTDP in the longer wavelength region. In contrast, compounds 2 , 3 and 4 with weaker acceptors ( 2 ; CH 3 −CO, 3 ; CH 3 −CH 2 −CO and 4 ; (CH 3 ) 2 −CH−CO) exhibit RTDP in a shorter wavelength region.