Photochemical generation of high-spin nitrenes from 4,6-diazido-N-(4,6-diazido-1,3,5-triazin-2-yl)-1,3,5-triazin-2-amine in solid argon

The photolysis of 4,6-diazido-N-(4,6-diazido-1,3,5-triazin-2-yl)-1,3,5-triazin-2-amine in argon matrices at 5 K has been studied, using X-band EPR spectroscopy in combination with modern line-shape spectral simulations and density functional theory computations. It was found that the photolysis of the model tetraazide occurs selectively to give only triplet 4-azido-6-nitreno-N-(4,6-diazido-1,3,5-triazin-2-yl)-1,3,5-triazin-2-amine (D =1.45 cm(-1), E = 0.0045 cm(-1)) and quintet 4,6-dinitreno-N-(4,6-diazido-1,3,5-triazin-2-yl)-1,3,5-triazin-2-amine (D = 0.276 cm(-1), E = 0.058 cm(-1)). The latter does not undergo further photolysis in the argon matrices since inappropriate spatial orientation of the second diazido-substituted triazine ring toward the UV source. The results obtained provide new data on photochemistry of aromatic tetraazides, formulating more strict requirements to the starting compounds as potential precursors of high-spin polynitrenes.