Investigation of C–H⋯X (X=N, O, S) intramolecular hydrogen bond in 1-vinyl-2-(2′-heteroaryl)pyrroles by ab initio calculations

• Published in: Journal of molecular structure. Theochem Vol. 680; no. 1; pp. 127 - 135
• Main Authors: Afonin, A.V., Toryashinova, D-S.D., Schmidt, E.Yu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.07.2004
• Subjects: Ab initio; Chemical shifts; Intramolecular hydrogen bonding C–H⋯X; Intramolecular hydrogen bonding C–H⋯X; Ab initio; Chemical shifts
• ISSN: 0166-1280; 1872-7999
• DOI: 10.1016/j.theochem.2004.02.020

The C–H⋯X (X=N, O, S) intramolecular hydrogen bond between the α-hydrogen of the vinyl group and the corresponding heteroatom in the series of 1-vinyl-2-(2′-heteroaryl)pyrroles was examined by ab initio calculations at the B3LYP/6-311(d,p) level. It was shown that the C–H⋯N hydrogen bond is stronger than the C–H⋯O hydrogen bond and the latter is, in turn, stronger than the C–H⋯S hydrogen bond. This conclusion is supported by calculations of 1H NMR chemical shieldings.