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Solid State and Solution Structures of O ‐Alkyl‐ and of O ‐Acyl Derivatives of 1‐Hydroxypyridine‐2(1 H )‐thione
Author(s) -
Hartung Jens,
Hiller Margit,
Schwarz Michaela,
Svoboda Ingrid,
Fuess Hartmut
Publication year - 1996
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199619961222
Subject(s) - chemistry , alkyl , solid state , differential scanning calorimetry , molecule , crystallography , carbon 13 nmr , medicinal chemistry , stereochemistry , organic chemistry , thermodynamics , physics
Although Barton's radical precursors, the O ‐acyl derivatives of 1‐hydroxypyridine‐2(1 H )‐thione 2 , have been studied in detail for more than a decade, to date nothing has been reported on the solid state or the solution geometries of these molecules or the analogous oxo derivatives, the pyridones 7, 8 . In view of this, selected O ‐alkyl and O ‐acyl derivatives of pyridinethiones and of 2‐(1 H )pyridones have been prepared and investigated by X‐ray diffraction and NMR (COSY, NOE) experiments. The X‐ray data indicate alternating bond lengths in the carbon framework of the heterocycles 2d, 3b, 7b , and 8 and long NO bonds [1.394(4)–1.398(2) Å]. In all the compounds studied, the O ‐alkyl and the O ‐acyl groups are twisted out of the plane of the heterocycles, which is in accord with the VSEPR concept. Further, the thermal stabilities of thiohydroxamic acid derivatives 2, 3 and of substituted pyridones 7, 8 were studied by differential scanning calorimetry (DSC).