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Investigation of intramolecular sulfur‐nitro interactions in 2‐(2′‐pyridylthio)‐3‐nitropyridine by 13 C‐NMR spectroscopy and x‐ray crystallography
Author(s) -
Kimura Michio,
Simonsen Stanley H.,
Caldwell Steven R.,
Martin Gary E.
Publication year - 1981
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570180306
Subject(s) - chemistry , intramolecular force , crystallography , molecule , ring (chemistry) , pyridine , nitro , crystal structure , nuclear magnetic resonance spectroscopy , protonation , relaxation (psychology) , hydrogen bond , stereochemistry , medicinal chemistry , organic chemistry , ion , social psychology , psychology , alkyl
The single crystal X‐ray diffraction structure of 2‐(2′‐pyridylthio)‐3‐nitropyridine is reported. A non‐bonded interaction was observed between the sulfur atom and one of the oxygen atoms of the nitro group with an interatomic distance of 2.678 A. Examination of the molecule's behavior in solution by 13 C‐nmr spin‐lattice (T 1 ) relaxation measurements showed the non‐nitro bearing pyridyl ring to reorient anisotropically about the C2′‐C5′ bond axis. In contrast, the nitro substituted pyridine ring did not appear to exhibit anisotropic reorientation about the corresponding C2‐C5 bond axis. Rather, approximately equivalent relaxation times were noted for all protonated ring carbons, indicating that the relaxations of this portion of the molecule were governed by the overall isotropic reorientation of the system. Based on these observations, it was concluded that the intramolecular sulfur‐nitro interaction also operates in the solution state and is sufficiently strong to prevent free rotation of the substituted portion of the molecule about the C2‐S bond axis.