Bulky Substituent Effect on Reactivity of Localized Singlet Cyclopentane‐1, 3‐diyls with π‐Single Bonding (C‐π‐C) Character. Issue 23 (23rd October 2019)

• Record Type: Journal Article
• Authors: Akisaka, Rikuo; Abe, Manabu
• Is Part Of: Chemistry, an Asian journal. Volume 14:Issue 23(2019)
• Page Start: 4223
• Page End: 4228
• Publication Date: 2019-10-23
• Subjects: enthalpy-entropy compensation -- Kinetic stabilization -- laser flash photolysis -- singlet diradicals -- steric effect; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201901253
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: Thorough investigation of key intermediates, such as long‐lived singlet diradicals, is essential to understand the homolytic bond cleavage reactions. In this study, we evaluate the effect of bulky substituents at the meta ‐position of the phenyl ring on the bond formation process in singlet 2, 2‐diethoxy‐1, 3‐diarylcyclopentane‐1, 3‐diyls. The bulky groups have significant influence on the diradical lifetime, as such, when the triisopropylphenyl group was used, the lifetime was 45 times longer than that of the parent diradical in benzene at 293 K. Abstract : The effect of bulky substituents at the meta ‐position of the phenyl ring on the bond formation process in singlet diradicals has been evaluated. When the triisopropylphenyl group is introduced, the lifetime is found to be 40 times longer than that of the parent diradical in benzene at 293 K.