Strong proton-shared hydrogen bonding in a methyl imidazole···HCl complex: evidence from matrix isolation infrared spectroscopy and ab initio computations was written by Sarkar, Shubhra;Sruthi, P. K.;Ramanathan, N.;Sundararajan, K.. And the article was included in New Journal of Chemistry in 2020.Recommanded Product: 3034-41-1 This article mentions the following:
Me imidazole (M-Imid)···HCl (1 : 1) complexes were studied using matrix isolation IR spectroscopy and ab initio computations. Computations using the MP2 level of theory with the aug-cc-pVDZ basis set predicted three complexes, where the global min. had a strong hydrogen-bonded N···H···Cl interaction with a binding energy of ~12 kcal mol-1 (complex A). The first local min. had an H···π interaction (complex B) and the second local min. (complex C) was stabilized through combined hydrogen, halogen and pnicogen bonding (with a nitrogen atom as the pnicogen) interactions. Of the three complexes, the hydrogen-bonded complex A alone possesses exptl. significance. Experiments were performed by co-depositing M-Imid and HCl sep. in an N2 matrix at a low temperature of ~12 K. The annealing of the low temperature matrix encouraged the formation of M-Imid-HCl complex A, which was subsequently probed using IR spectroscopy. Exptl., the vibrational shift of ~1720 cm-1 was observed for the N2 matrix, while harmonic frequency calculations indicated a shift of 1063 cm-1 in the H-Cl stretching region of the strong hydrogen-bonded complex A. The inclusion of anharmonicity in the calculations red-shifted the H-Cl stretching frequency further down to 1650 cm-1, which was almost close to the exptl. value. It is inferred from this large exptl. red-shift of the stretching frequency of the proton donor that proton-shared hydrogen bonding is facilitated in the M-Imid-HCl system exptl. Using atoms in mols., energy decomposition and natural bond orbital analyses, the uniqueness of this strong proton-shared hydrogen bonding is established with respect to conventional hydrogen bonding. In the experiment, the researchers used many compounds, for example, 1-Methyl-4-nitroimidazole (cas: 3034-41-1Recommanded Product: 3034-41-1).
1-Methyl-4-nitroimidazole (cas: 3034-41-1) belongs to imidazole derivatives. Among the different heterocyclic compounds, imidazole is better known due to its broad range of chemical and biological properties. Imidazole has become an important synthon in the development of new drugs. Many drugs contain an imidazole ring, such as certain antifungal drugs, the nitroimidazole series of antibiotics, and the sedative midazolam.Recommanded Product: 3034-41-1
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem