Infrared, density-functional theory, and atoms in molecules method studies on conformers of some 2-substituted 1H-pyrroles

Methyl pyrrole-2-carboxylate (MPC), pyrrole-2-carbaldehyde (PC), methyl N-methylpyrrole-2-carboxylate (MPC-NMe), and N-methylpyrrole-2-carbaldehyde (PC-NMe) are investigated. The experimental and theoretical results show that for all the species investigated, the s-cis conformer is dominant in solution, and it is more stable than the s-trans conformer.