Synthesis Of New Tetrazines Functionalized With Photoactive And Electroactive Groups

In this thesis, we have been prepared different groups of s-tetrazine derivatives for the electrochemical and fluorescence studies.In the first part, we discuss the s-tetrazine derivatives as the ion pair receptor. This type of interactions between ion pairs and s-tetrazines has been seldom observed in solution. The formation of complex between the ammonium salt (C8H17NH3+·Br-and C8H17NH3+·I-) and s-tetrazines (80,81and82) is demonstrated by NMR titration experiments. It is also proved that receptor82binds stronger to ammonium salt than the shorter equivalents80and81by NMR and fluorescence titration. Furthermore, both of them give the same selectivity order to receptors is I-> Br-> Cl-. Taking fully into account the UV-vis absorption, NMR and fluorescence titration experiments, we proposed the mechanism, including the process of the formation the complex and the side reaction products:I2or Br2.In the second part, in order to understand deeply the physico-chemcal properties of s-tetrazine, various s-tetrazines with different types of substituents have been prepared. It is clear that the electrochemical property depends on the electron affinity of the substituent, not on its size. Furthermore, the electron donor group quenches the fluorescence of s-tetrazine (compound124and125) even if they are not directly linked (97,135and137). A new type of s-tetrazines has been obtained through an unexpected reactivity of chloro-s-tetrazine. This reaction could give unsymmetrical s-tetrazine bearing one heteroatom and one alkyl chain which is useful in the fluorescence and electroactivity research.In the last part, but it is also the important part in this thesis, we talk about the improved s-tetrazines dyads. Base on energy transfer from the donor part (naphthalimide or benzimidazole) to acceptor core (tetrazine), these compounds own good fluorescence quantum yields, longer life time and higher brightness. Besides the excellent fluorescence properties, compound112owns two stable (one is reversible, and the other is less reversible) and independent anion-radicals which is useful accompany with fluorescence behavior.