Synthesis of new pyrazolyl-1,3-diazabicyclo[3.1.0]hexe-3-ene derivatives

•A series of 1,3-diazabicyclo[3.1.0]hex-3-enes containing pyrazole moiety have been prepared.•The structures characterized by IR, 1H NMR, 13C NMR, and UV–Vis spectra.•Photochromic behavior in the both solid and solution phases.•1,3-Diazabicyclo[3.1.0]hex-3-enes containing thiophene fragment have been synthesized.

A series of new of photochromic 1,3-diazabicyclo[3.1.0]hex-3-ene derivatives based on the skeleton of five-membered pyrazole moiety have been synthesized and characterized by spectral techniques, as well as their photochromic properties were examined under UV light irradiation in various solutions. All these newly synthesized compounds showed good photochromic properties in the both solution and solid states. The UV–Visible spectral analysis of the corresponding pyrazolyl bicyclic aziridines established structure-photochromic behavior relationships.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide