Spectral and kinetic characteristics of cycloalkyl radicals in the liquid phase

The C₅–C₁₀ cyclolakyl radicals have a weak light absorption in the 240–300 nm wavelength range that is due to Rydberg transition to the 3s orbital. The extinction coefficients at 250 nm are in the range of 350–900 mol^–1 dm³ cm^–1. At this wavelength for the C₆–C₁₀ radicals a local maximum appears. The radical decay obeys second order kinetics. The kinetic characteristics of the cyclic and linear radicals are generally similar, indicating that the rings are flexible and can easily overcome steric constraints in the termination process. Both the light absorption and decay characteristics of the cyclopentyl radical are somewhat different from those of the other radicals that are attributed to the special co-planar arrangement.