Synthesis, crystal structures and electrochemical properties of ferrocenyl imidazole derivatives

Abstract

Six ferrocenyl imidazole derivatives substituted with -Cl, -NO2 and -CH3 on the 2-position of the 1H-imidazole ring have been synthesized. Of the six compounds, the di-substituted ferrocenes, i.e. compounds 4 (1,1′-ferrocenylmethyl(2-chloroimidazole)), 5 (1,1′-ferrocenyl(2-nitroimidazole)), and 6 (1,1′-ferrocenylmethyl(2-methylimidazole)) are reported for the first time. The structure-property relationships of compounds 4, 5 and 6 were investigated by means of UV-visible, FTIR, 1H-NMR, 13C-NMR spectroscopy and electrochemical studies. UV-visible analysis in acetonitrile showed that the π -π* band of compounds 2 (1-ferrocenylmethyl(2-nitroimidazole)) and 5 appeared at longer wavelength compared to 1 (1-ferrocenylmethyl(2-chloroimidazole)), 3 (1-ferrocenylmethyl(2-methylimidazole)), 4 and 6. This phenomenon is due to the different electronics around the imidazole moieties. In cyclic voltammetry analysis, all compounds exhibited a quasi-reversible redox wave for the ferrocenyl and imidazole moieties. Density functional theoretical (DFT) calculations with the B3LYP/6-311+G(d) basis set were performed on compounds 1–6, and the calculated HUMO-LUMO band gap energies correlated with those obtained from electrochemical and spectroscopic data. The X-ray crystallographic analysis highlighted the effect of electron-withdrawing and electron-donating substituents on the conformation of the cyclopentadienyl rings attached to the ferrocenyl moiety.

Ferrocene‐modified imidazoles: One‐pot oxalyl chloride‐assisted synthesis, HPLC enantiomeric resolution, and in vivo antitumor effects

“…Therefore, the above method turned out to be suitable for the synthesis of ferrocenylalkyl derivatives of nitroimidazoles, with yields up to 60%–70%, [ 31 ] and perfluoroalkyl benzimidazoles, with yields up to 90%. [ 26 ] Fc‐alkylation of imidazoles and their alkyl derivatives can be carried out in 65% acetic acid [ 38 ] or in the acetone–trifluoroacetic acid. [ 30 ] The target compound yields are good and reach 74%.…”

Novel Fluorescent Tetrahedral Zinc (II) Complexes Derived from 4-Phenyl-1-octyl-1H-imidazole Fused with Aryl-9H-Carbazole and Triarylamine Donor Units: Synthesis, Crystal Structures, and Photophysical Properties

“…Examples of N-heterocyclic systems, such as imidazole and its derivatives, have piqued the curiosity of researchers interested in developing hybrid organic-inorganic systems for various applications [2,[14][15][16][17][18]. The unique properties of imidazole-based complexes, such as excellent electrochemical and photoluminescent properties, excellent thermal properties, and ease of modification, were taken into account in the design of various host materials such as electron transport, fluorescent, or phosphorescent molecules [19][20][21][22][23]. Over the years, several articles have reported the coordination of imidazole-based synthons with a variety of metal ions, including cobalt, nickel, iron, zinc, copper, and iridium, leading to the preparation of stable organic metal complexes [9][10][11][12][13][24][25][26][27].…”

Linkage between Fluorescence and Electrochemical Properties of Imidazolium Compounds in Acetonitrile Solution

“…Association of different approaches, as X‐ray diffraction analysis, NMR and IR spectroscopies, electrochemistry, photophysical and theoretical chemistry methodologies are very fruitful in knowing the electronic density distribution and its relationship with the molecular structure and conformation . The imidazolium derivatives have been used as starting material for the design of catalyzers in organic synthesis .…”