Abstract

L. Ushakumari¹, C.Yohannan Panicker¹*, Hema Tresa Varaghese², Haseena¹, A.V. Vaidyan³, Nisha Sudhakaran³ And K. Raju⁴

A substituted amide of pyrazine-2-carboxylic acid was prepared and the IR spectrum is recorded and analysed. The vibrational wavenumbers of the title compound have been computed using the Hartree-Fock level of theory using 6-31G* basis set and compared with the experimental data. The first hyperpolarizability, Infrared intensities and Raman activities are reported. The red shift of the NH stretching wavenumber indicates the weakening of the NH bond. Methyl substitution affects all the carbon-nitrogen and carbon-carbon bond lengths of the pyrazine ring of the title compound in comparison with the corresponding bonds of pyrazine. Increase in conjugation, enhances the infrared intensity of the carbonyl stretching vibration. The splitting of NH stretching bond is due to Davidov coupling between neighbouring units.

Amides of pyrazine carboxylic acid; IR; Hartree-Fock ab initio calculations; hyperpolaziability

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