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The contact charge transfer absorption spectrum of dimethylsulphoxide with oxygen

1995; Elsevier BV; Volume: 51; Issue: 4 Linguagem: Inglês

10.1016/0584-8539(94)00173-9

1873-3557

Martin M. F. Choi, Peter Hawkins,

Analytical Chemistry and Sensors

Dimethylsulphoxide (DMSO) produces a strong ultraviolet contact charge transfer (CCT) absorption band with oxygen (O2) with an intensity directly proportional to the partial pressure of the applied O2 and the mole percentages of DMSO in a DMSO/acetonitrile solvent mixture. The CCT absorption spectrum is similar to, but much weaker than, that of the superoxide (O2−) ion in DMSO. Superoxide ions are also produced by adding a small amount of sodium hydroxide (NaOH) to DMSO. Electron spin resonance spectroscopy confirms the presence of O2− ions in a 5 mmol dm−3 NaOH, 1% (v/v) water in DMSO solution but no spectrum is observed in an oxygenated DMSO solution at 77 K.