Singlet Sigma: The "Other" Singlet Oxygen in Solution

Singlet Oxygen

Singlet oxygen (O2) is a higher energy state molecular oxygen species. It is one of the most active intermediates involved in chemical and biochemical reactions. To fully appreciate the reactivity of O2, it is necessary to understand its physical and chemical nature. This paper reviews the generation, quenching and detection of O2. Its properties, possible chemical reactions are presented as we...

Singlet Oxygen Trapping Porphyrins

Singlet oxygen mediated photooxidation of penciclovir in aqueous solution

Photodegradation of an aqueous solution of Penciclovir (PC, 1) in phosphate buffer (pH 7) under aerobic condition was studied with light of wavelength>270 nm. Three major oxidation products were detected by means of spectroscopic measurements. The products were 4-hydroxy-(3-Hydroxymethyl) butyl spiro imino dihydantion (2), 4[4-hydroxy(3hydroxymethyl)butylamino]-2-imino-1,2-dihydroimidazol-5-one...

Fiber-optic Singlet Oxygen

Traditionally, Type II heterogeneous photo-oxidations produce singlet oxygen via external irradiation of a sensitizer and external supply of ground-state oxygen. A potential improvement is reported here. A hollow-core fiber-optic device was developed with an ‘‘internal’’ supply of light and flowing oxygen, and a porous photosensitizer-end capped configuration. Singlet oxygen was delivered throu...

Singlet Oxygen-Induced Arrhythmias

In a study of aerobically perfused rat hearts, the in situ photoactivation (530-590 nm) of rose bengal (a process that leads to the production of singlet oxygen and superoxide) has been shown to lead to the rapid development of electrocardiographic abnormalities and arrhythmias. With rose bengal concentrations of 1,000, 500, 250, 100, and 50 nmol/l (n =6/group), photoactivation (3,600 lx) led t...