Dibenzoarsepins: Planarization of 8π‐Electron System in the Lowest Singlet Excited State. (24th July 2019)

• Record Type: Journal Article
• Authors: Kawashima, Ikuo; Imoto, Hiroaki; Ishida, Masatoshi; Furuta, Hiroyuki; Yamamoto, Shunsuke; Mitsuishi, Masaya; Tanaka, Susumu; Fujii, Toshiki; Naka, Kensuke
• Is Part Of: Angewandte Chemie. Volume 131:Number 34(2019)
• Page Start: 11812
• Page End: 11816
• Publication Date: 2019-07-24
• Subjects: Angeregte Zustände -- Aromatizität -- Arsepine -- Baird-Regel; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201904882
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Dibenzo[b, f]arsepins possessing severely distorted cores compared to those of other heteropins were synthesized. These derivatives exhibited dual photoluminescence in the green‐to‐red region (500–700 nm) and the near‐ultraviolet region (<380 nm), which could be attributed to the planarization of the arsepin core in the lowest singlet excited (S1 ) state. The computational approach for the assessment of the aromatic indices revealed that the dibenzoarsepins studied show aromaticity (8π system) in the S1 states in line with Baird's rule. The lone pair electrons of the arsenic atoms play a crucial role in the aromaticity in the S1 states. Abstract : Aromatizität im angeregten Zustand : Dibenzoarsepine mit formalen 8π‐Elektronensystemen zeigen hoch gebogene Strukturen in den Grundzuständen, während quasiplanare Strukturen in den angeregten Singulettzuständen begünstigt sind. Die drastische konformative Veränderung bei Photoanregung ist in Einklang mit der Baird‐Regel.