Inter- and intramolecular hydrogen bonds – Structures of 1-methylpyrrole-2-carboxamide and 1-hydroxypyrrole-2-carboxamide

The structures of 1-methylpyrrole-2-carboxamide (MPCA) and 1-hydroxypyrrole-2-carboxamide (HPCA) are analyzed, for both structures B3LYP/6-311++G(d,p) calculations were performed on s-cis and s-trans conformations and on monomeric and dimeric forms of these conformers. N–H⋯O hydrogen bonds exist for dimers. The X-ray crystal structure of MPCA is also analyzed; centrosymmetric dimers of syn conformers connected through N–H⋯O hydrogen bonds exist in crystal structure as well as C–H⋯O intramolecular interactions possessing some of characteristics typical for hydrogen bond.