Figure 5.

Panel A: Kinetics of O₂(¹Δ_g) luminescence after excitation by laser pulse (wavelength 308 nm and pulse width ~28 ns): SF on steel immersed in air-saturated chloroform (a); extract from SC-500 in air-saturated chloroform before (b) and after addition of methanol (c); standard anthracene in air-saturated chloroform (d); and extract from SC-500 in argon-saturated chloroform (e, no generation of singlet oxygen) for comparison. Red lines are single exponential fits into experimental data. Individual traces are offset. Panel B: UV–Vis spectrum of the extract from SC-500 in chloroform, arrow designates excitation wavelength.