Broadening the Horizon of the Bell–Evans–Polanyi Principle towards Optically Triggered Structure Planarization. Issue 13 (24th February 2021)

• Record Type: Journal Article
• Authors: Chen, Yi; Chang, Kai‐Hsin; Meng, Fan‐Yi; Tseng, Sheng‐Ming; Chou, Pi‐Tai
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 13(2021)
• Page Start: 7205
• Page End: 7212
• Publication Date: 2021-02-24
• Subjects: azepine -- Bell–Evans–Polanyi principle -- dual emission -- excited-state aromaticity -- photoinduced structural planarization; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202015274
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Finding a relationship between kinetics and thermodynamics may be difficult. However, semi‐empirical rules exist to compensate for this shortcoming, among which the Bell–Evans–Polanyi ( B‐E‐P ) principle is an example for reactions involving bond breakage and reformation. We expand the B‐E‐P principle to a new territory by probing photoinduced structure planarization (PISP) of a series of dibenz[ b, f ]azepine derivatives incorporating bent‐to‐planar and rotation motion. The latter involves twisting of the partial double bond character, thereby inducing a barrier that is substituent dependent at the para N ‐phenyl position. The transition‐state structure and frequency data satisfy and broaden the B‐E‐P principle to PISP reactions without bond rearrangement. Together with dual emissions during PISP, this makes possible harnessing of the kinetics/thermodynamics relationship and hence ratiometric luminescence properties for excited‐state structural transformations. Abstract : The Bell–Evans–Polanyi principle was used to probe photoinduced structure planarization of a series of dibenz[ b, f ]azepine (DBA ) derivatives incorporating bent‐to‐planar and rotation motion. A saddle point was calculated for all PDBAs along the structural transition pathway. A relationship was elucidated between kinetics and thermodynamics, providing insight into the ratiometric luminescence properties of excited‐state structural transformations.