Characterizations of crystalline structure and catalytic activity of zwitterionic imidazole derivatives

S. Yebdri (1) , O. Nehar (1) , R. Mahboub (1) , T. Roisnel (2) , L. Boukli-Hacene (1) , S. Louhibi (1)

1 Université Aboubekr Belkaid - University of Belkaïd Abou Bekr [Tlemcen]
2 ISCR - Institut des Sciences Chimiques de Rennes

The zwitterion ligand L1 has been synthesized and characterized by single-crystal X-ray diffraction, and spectroscopic techniques (1H, 13C NMR, FT-IR, ESI-MS, and UV–Vis). The crystal structure shows that L1 molecules are planar and are connected via intermolecular N-H——O and intramolecular N-H——O interactions. The NMR analysis shows the presence of two mesomeric forms of L1 zwitterion and ketone-imidazolidine. The kinetic study of in situ complexes is followed by UV–vis spectroscopy and revealed a binuclear structure built from square base pyramidal geometry and octahedral one. In situ complexes obtained from L1 with different copper (II) salts are studied for their catecholase activities using 3,5-di-tert-butylcatechol. The obtained 3,5-di-tert-butylquinone was characterized by single-crystal X-ray diffraction,. The results show that the catalytic activity depends on the nature of the metal salt anion. From Michaelis-Menten model, we have evaluated the dissociation constant and the bond constant which are in good agreement with those of literature. The structure-activity relationship show that the high rate of catalytic oxidation depends on the presence of copper ion in the complex.

Keywords: Zwetterionic form; X-Ray; Catechol oxidase; Imidazole derivative

Domains: Chemical Sciences; Catalysis; Chemical Sciences; Cristallography

S. Yebdri, O. Nehar, R. Mahboub, T. Roisnel, L. Boukli-Hacene, et al.. Characterizations of crystalline structure and catalytic activity of zwitterionic imidazole derivatives. Journal of Molecular Structure, 2019, 1193, pp.45-52. ⟨10.1016/j.molstruc.2019.05.020⟩. ⟨hal-02161326⟩