Document Type : Original Paper


Department of Chemistry, Islamic azad university, mahshahr branch, Mahshahr, Iran


The internal strain in cyclic amides are explained as a factor of resonance that are effected on the bond length C-N  and are a major factor of rates of hydrolysis. The cyclic amides in this study are optimized by Gaussian program and the bond length of C-N in the rings are studied by HF/6-31G*.