Heteronuclear intermolecular resonance-assisted hydrogen bonds. The structure of pyrrole-2-carboxamide (PyCa).
The crystal and molecular structure of pyrrole-2-carboxamide (PyCa) determined by single crystal X-ray diffraction is presented. Molecular conformations of PyCa are also analyzed by FT-IR and NMR techniques. Additionally DFT calculations at the B3LYP/6-311++G(d,p) level of approximation are performed for dimers of PyCa and for related species. The existence of two tautomeric forms for the analyzed dimers differing in H-bond motifs, N-H...O or O-H...N, is studied. The geometrical and energetic features of such H-bonds show that these interactions may be classified as intermolecular resonance-assisted hydrogen bonds. Additionally the Bader theory is applied to determine and to analyze bond critical points.
Department of Crystallography and Crystal Chemistry, University of Lodź, ul. Pomorska 149/153, 90-236 L-odź, Poland.
Sławomir J
SJ
Grabowski
Alina T
AT
Dubis
Marcin
M
Palusiak
Jerzy
J
Leszczynski