Figure 4.

a) Selected UV spectra of the thermal relaxation of the meso diazocine 3 in THF at 233 K after irradiation at 385 nm. b) UV spectra of the n–π* transition of the diazocines 3 (top) and 4 (bottom) before and after irradiation at 385 nm in THF at 298 K. The UV spectra of the pure trans isomers 3 and 4 were obtained through extrapolation.