Photophysical properties of (O-2((1)Delta(g)))(2) and O-2((1)Sigma(+)(g)) in solution phase

Using the C-60 fluorescence as a reference in combination with the direct spectroscopic observation of O-1(2) visible emission, the photophysics of O-1(2) dimol (((1) Delta(g))(2)) and O-2((1) Sigma(g)(+)) states in solution has been studied. The quantum yield of O-2 (1) Sigma(g)(+)-->(3) Sigma(g)(-) (765 nm) emission has been measured to be 1.94 x 10(-7), and consequently, the radiative decay rate of (1) Sigma(g)(+)-->(3) Sigma(g)(-), transition was determined to be 1.55 +/- 0.04 s(-1) which, within the experimental error, is consistent with the previous report of 0.46 s(-1).(4) Further determination of the ratio between radiative decay and dissociation rates of the (1) Delta(g), dimol has been achieved by comparing the dimol ((1) Delta(g))(2)-->((3) Sigma(g)(-))(2) emission intensity with the tetra-tert-butylphthalocyanine delayed fluorescence induced by a two-step energy transfer from the O-2((1) Delta(g)) state. As a result, the lower limit of the dissociation rate constant of the dimol was estimated to be (2.6 +/- 0.3) x 10(10) s(-1) in CCl4.