Mechanism of singlet oxygen interaction with solvent removing prohibition of the radiative 1Δg → 3Σ−g transition in oxygen

✍ Scribed by Alexander P. Darmanyan

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 564 KB
• Volume: 215
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)85705-s

✦ Synopsis

The values of relative 0s ('A,) luminescence rate constant (kp ) in thirty-two solvents with ionization potentials IP = 8-l 1 eV are satisfactorily described by a linear dependence of log (kp /n 2, versus IP with a slope of -0.30 eV-i. Singlet oxygen acting as an electron acceptor forms a loose exciplex with a partial charge transfer with solvents acting as electron donors; CT interactions remove the prohibition on the radiative '4 + 22; transition in oxygen. In the region IP p> 11 eV, the solvents are very poor electron donors at least for strong electron acceptors such as Ccl, and chloroform and also for as weak an electron acceptor as water a reverse electron transfer should occur from oxygen to the solvent molecule.