Premium
Unusually Long‐Wavelength Emissions of Cyclopropanes: New Insight into C−C Bond Homolysis
Author(s) -
Abe Manabu,
Kanahara Kousei,
Kadowaki Norito,
Tan ChunJui,
Tsai HuiHsu Gavin
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201800671
Subject(s) - homolysis , diradical , ab initio , singlet state , chemistry , chemical bond , chemical physics , computational chemistry , excited state , atomic physics , physics , radical , organic chemistry
Bond homolysis (BHo) is a fundamental concept in chemical‐bonding phenomena. To date, research studies on the BHo concept have provided crucial information for understanding the nature of chemical bonding and reactions. Two potential‐energy minima, a σ‐bonding isomer and a singlet‐diradical isomer, have been known to exist in carbon–carbon BHo. Herein, a third isomer, that is, a puckered singlet diradical exhibiting unstructured long‐wavelength fluorescence beyond 460 nm, was first observed in the excited states of 1,4‐diarylbicyclo[2.1.0]pentane derivatives. The careful selection of appropriate substituents in the bicyclic structures enabled direct spectral detection. State‐of‐the‐art ab initio quantum chemical calculations quantitatively reproduced the experimental observations. This new finding provides new insight into carbon–carbon bond‐breaking and ‐forming processes.