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Laser-based and solution-phase emission experiments are performed to study the chemical reactivity of singlet sigma oxygen (b1-sigma-g+) in solution. The experiments are carried out at various quencher excitation levels using deuterated and halogenated quenchers. Spectroscopic data reveals that the removal of b1-sigma-g+ from a solution phase system by chemical reaction does not compete effectively with both quencher- and solvent-induced physical deactivation channels that produce the lowest excited electronic state of oxygen.

The photodegradation of poly(2,5-bis(5,6-dihydrocholestanoxy)-1,4- phenylenevinylene) (BCHA-PPV) in solid films and liquid solutions involve a chain cleavage of BCHA-PPV and leads to the production of a reactive singlet oxygen intermediate. The transfer of energy from the BCHA-PPV triplet state to the ground state oxygen leads to the formation of the singlet oxygen. The polymer degradation reaction takes place by adding a singlet oxygen in a Pi2 + Pi2 cycloaddition reaction to the double bond that unites phenylene groups in the macromolecule.

A study investigated the effect of solvent on the O2(b1Sigma subg supra+) - O2(a1Deltag) fluorescent emission spectrum. The dependence of O2(b1Sigma subg supra+) - O2(a1Deltag) and O2(a1DDeltag) - O2(X3Delta subg supra1) emission band maxima on the solvent refractive index n and the functions of n shows that the respective transition energies are affected in a similar manner by solvent perturbations. The electronic response of the solvent is also a significant component of the oxygen-solvent interaction. Other results are discussed.

Presents spectroscopic data for the chemical reactions of singlet sigma oxygen. Ground state of molecular oxygen; Excited electronic states of oxygen; Singlet oxygen quenchers; Quencher- and solvent-induced physical deactivation channels that produce oxygen.