Intra- and intermolecular hydrogen bonding and conformation in 1-acyl thioureas: An experimental and theoretical approach on 1-(2-chlorobenzoyl)thiourea

AAMER SAEED; ASMA KHURSHID; MICHAEL BOLTE; ADOLFO C. FANTONI; MAURICIO F. ERBEN

SPECTROCHIMICA ACTA A: MOLECULAR AND BIOMOLECULAR SPECTROSCOPY

ELSEVIER

Lugar: Amsterdam; Año: 2015 vol. 143 p. 59 - 66

0584-8539

The vibrational analysis (FT-IR and FT-Raman) for the new 1-(2-chlorobenzoyl)thiourea species suggeststhat strong intramolecular interactions affect the conformational properties. The X-ray structure deter-mination corroborates that an intramolecular N?H∙∙∙O=C hydrogen bond occurs between the carbonyl(?C=O) and thioamide (?NH2) groups. Moreover, periodic system electron density and topologicalanalysis have been applied to characterize the intermolecular interactions in the crystal. ExtendedN?H∙∙∙S=C hydrogen-bonding networks between both the thioamide (N?H) and carbamide (NH2) groupsand the thiocarbonyl bond (C=S) determine the crystal packing. The Natural Bond Orbital (NBO) popula-tion analysis demonstrates that strong hyperconjugative remote interactions are responsible for both,intra and intermolecular interactions. The Atom in Molecule (AIM) results also show that the N?H∙∙∙Clintramolecular hydrogen bond between the 2-Cl-phenyl ring and the amide group characterized in thefree molecule changes to an N∙∙∙Cl interaction as a consequence of crystal packing