Electronic Structure and Biological Activity of Pyrazine and Its Alkyl Derivatives by Quatum-Chemical Calculations

摘要

3-21G ab initio and PM3 semiempirical calcultions of the equilibrium geometry and the electronic structure of pyrazine and its alkyl derivatives,tetramethylpyrazine,triethylpyrazine,and tetraethyl-pyrazine,were performed.Indices of electronic structure were found,that correlate with the biological activity of teh compounds studied: charges on teh nitrogen atoms and energies of teh highest occupied molecular orbitals.It was shown that the biological activity of the compounds in study is adequately described by the semiempirical calculations.