In:
Angewandte Chemie International Edition, Wiley, Vol. 58, No. 38 ( 2019-09-16), p. 13297-13301
Abstract:
Phenothiazine derivatives based on the 10‐phenyl‐10H‐phenothiazine ( NAS ) chromophore, namely 7‐phenyl‐7 H ‐benzo[c]phenothiazine ( NAS‐1 ) and 12‐phenyl‐12H‐benzo[a]phenothiazine ( NAS‐2 ), were designed and synthesized. NAS‐1 and NAS‐2 are constitutional isomers with different steric strains imposed on the phenothiazine core moiety. In solution, the more‐strained NAS‐2 possesses a bent structure and undergoes photoinduced structural planarization (PISP). In the crystal, despite the absence of PISP, bent NAS‐2 exhibits prominent excimer emission as well as emission mechanochromism, which is not observed in the planar‐like NAS and NAS‐1 . This unconventional observation results from the bent core structure facilitating π–π stacking of the peripheral naphthalene moieties. Two‐photon‐coupled depth‐dependent emission shows spectral differences between the surface and kernel of the NAS‐2 crystal, and is believed to be a general phenomenon, at least in part, for materials exhibiting emission mechanochromism.
Type of Medium:
Online Resource
ISSN:
1433-7851
,
1521-3773
DOI:
10.1002/anie.201906083
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
2011836-3
detail.hit.zdb_id:
123227-7
