New tetrazines substituted by heteroatoms including the first tetrazine based cyclophane: Synthesis and electrochemical properties

New tetrazines substituted by heteroatomic substituents have been prepared, and their physicochemical properties investigated. In particular, a cyclophane containing three tetrazine units was synthesised and its crystal structure demonstrated. The electrochemical and fluorescence properties of these new compounds were investigated, as well as the sensing ability of the cyclophane toward several electron-rich and hydroxy substituted compounds. Interactions between the anion-radical of the tetrazine compounds and the phenol derivative were evidenced through spectroscopic and electrochemical measurements. In the case of the cyclophane compounds, these interactions occur probably through H-bonding, whereas proton transfer is evidenced in the case of the linear bisbutanedioxy substituted tetrazine.