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Ab initio studies on the nonplanarity of a peptide unit: Calculations on model compounds

✍ Scribed by A. Sawaryn; J. S. Yadav

Publisher
John Wiley and Sons
Year
1982
Tongue
English
Weight
521 KB
Volume
22
Category
Article
ISSN
0020-7608

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✦ Synopsis

Abstract

The nonplanarity of a peptide unit has been studied by the ab initio method (GAUSSIAN 76) considering both the pyramidal structure of nitrogen and the variation of the ω angle for the N‐methyl‐acetamide and N‐ethyl‐acetamide in their cis and trans conformations. Several semiempirical methods have also been used for the sake of completeness of this work. All methods except CNDO and PCILO support a nonpyramidal structure for the nitrogen. The distortions of the planarity of the peptide unit show for both cis and trans conformations of the model compounds a significant asymmetric shift of the minimum on the energy curve for the ω rotation.

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