Solvent reordering of low lying triplet states in some aromatic carbonyls

✍ Scribed by J.B Gallivan; J.S Brinen

• Book ID: 103013760
• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 675 KB
• Volume: 10
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(71)80333-0

✦ Synopsis

Various pa&meters of the phosphorescent state of chrornoke, 4-chromanone and 3',4'dime&acetophenenone were examined ih solvents of very different polarities. Phcndmena examined tiere phosph&cence emission and excitation spectra, polarized phosphorescence specki; phosphoiesccncq lifetimes, singkt-triplet absorption under oxygen pressure, and EPR spectra'kf !jte triplet state. Analysis of the combined data from these studies indicate that Iow lying n,n* and X,R* triplet gates of chromone and 3',4'dimethyfac.&ophenone are nearly iso-enexgetic, very strongly mixed, and can be reordered by changing solvents. No such r!zordering of states was indicated for 4-chromanone, suggesting a timewhat greater energy gap between the n,n* and n,k* states.