Photochemie diarylsubstituierter 2H‐Tetrazole. II. Zum Einfluß der Substituenten auf die Absorptionseigenschaften diarylsubstituierter Nitrilimine

Photochemistry of Diarylsubstituted 2H‐Tetrazoles. II. The Influence of the Substituents on the Absorption Properties of Diarylsubstituted Nitrilimines Irradation of 2,5‐diaryl‐2H‐tetrazoles in an EPA‐glass (ether: i‐pentan: ethanol=5:5:2) or in an i‐pentan glass at 77‐80 K with UV‐light of wavelength 290 nm yields diarylnitrilimines by the extrusion of nitrogen. The photoreactions investigated show spectroscopic unity. 22 diarylnitrilimines are included in the discussion with regards to the influence of substituents on the absorption maxima. The influence of substituents is interpreted by a LFE‐relationship. An intramolecular charge transfer as the reason for the relatively strong dependence of ν‐values on substituents is discussed.