G3XMP2 INVERSION STUDIES OF HETEROAROMATIC AMINES, N-ANILINE AND N, N-ANILINE DERIVATIVES
Objective: Nitrogen inversion in aniline and hetero aromatic amines are contrary in nature and hence inversion dynamics of the above two compounds are investigated by G3XMP2 theory to determine the configuration of the amine group. Besides, the structure and dynamics of N-aniline and N,N-aniline derivatives are also studied in this report.
Methods: All the hetero aromatic compounds and N-aniline & N,N-aniline derivatives were optimized at DFT B3LYP/6-31G (2df, p) level of theory using the Gaussian 03 program. The inversion barriers of all the compounds were computed using the G3XMP2 theory.
Results: The amine inversion investigation divulges that the introduction of hetero atom in the ring significantly increases the planarity of the amine group by hyperconjugative effect and resonance effect. Hence pyridine and pyrimidine compounds attain planar configuration. Meanwhile N-methyl aniline and N,N-dimethyl aniline attains planar structure among all the N & N,N-aniline derivatives studied.
Conclusion: Introduction of hetero atom in the ring favours planar amine structure and hence, amino pyrmidines are more planar than the amino pyridine and aniline compounds. Likewise electropositive substituent like methyl group in N-methyl aniline & N,N-dimethyl aniline promotes planar amine structure.
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