19 research outputs found
Crystal structures and Hirshfeld surfaces of two 1,3-benzoxathiol-2-one derivatives
Acknowledgements We thank the EPSRC National Crystallography Service (University of Southampton) for the X-ray data collections.Peer reviewedPublisher PD
Crystallographic and computational study of t-butyl N-[3-hydroxy-1-phenyl-4-(pyridin- 2-ylsulfanyl)butan-2-yl]carbamate and its pyrimidin-2-yl analogue
Abstract
The crystal structure analysis of the biologically-relevant title compound (1) shows the carbonyl-O2 and amide-H atoms to be anti, and perpendicular relationships between the carbamate residue and the pyridyl ring [dihedral angle=84.60(10)°] and between the carbamate and aryl ring [74.84(11)°]; the rings are approximately co-planar [12.07(17)°]. An intramolecular hydroxyl-O–H···N(pyridyl) hydrogen bond that closes a S(7) loop is noted. Of interest is the observation that this hydrogen bond is not found in the structure of the pyrimidinyl analogue (2) which was characterised as a monohydrate, i.e. 2·H2O, in an earlier study. Density-functional theory calculations show the observed conformation in 1 is 2.0 kcal/mol more stable than the conformation where the intramolecular hydrogen bond is absent. This energy difference reduces to ca 0.5 kcal/mol in the case of 2. The differences in molecular conformations found for 1 and 2 are therefore ascribed to the dictates of overall molecular packing, in particular due to the influence of lattice water in 2·H2O.</jats:p
tert-Butyl N-[3-hydroxy-1-phenyl-4-(pyrimidin-2-ylsulfanyl)butan-2-yl]carbamate monohydrate
In the title hydrate, C19H25N3O3S·H2O, the configuration at each chiral centre in the organic molecule is S, with the hydroxy and carbamate substituents being anti [O—C—C—N torsion angle = −179.3 (3)°]. The thiopyrimidyl and carbamate residues lie to one side of the pseudo-mirror plane defined by the C5S backbone of the molecule; this plane approximately bisects the benzene ring at the 1- and 4-C atoms. The dihedral angle formed between the terminal rings is 5.06 (18)°. In the crystal, supramolecular tubes aligned along the b axis are found: these are sustained by a combination of O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds
N-{(2S)-3-Hydroxy-4-[(5-methyl-1,3,4-thiadiazol-2-yl)sulfanyl]-1-phenyl-2-butyl}-4-methylbenzenesulfonamide
The thiadiazoyl and sulfonyl-benzene rings in the title compound, C20H23N3O3S3, are aligned to the same side of the molecule, forming a twisted ‘U’ shape [dihedral angle = 77.6 (5)°]. The benzyl-benzene ring is orientated in the opposite direction from the molecule but projects approximately along the same axis as the other rings [dihedral angle between benzene rings = 28.2 (5)°] so that, overall, the molecule has a flattened shape. The hydroxy and amine groups are almost syn which enables the formation of intermolecular hydroxy-OH⋯N(thiadiazoyl) and amine-H⋯O(sulfonyl) hydrogen bonds leading to a supramolecular chain aligned along the a axis
Four substituted benzohydrazides: hydrogen-bonded structures in one, two and three dimensions
The molecules of 2,6-dichloro-benzohydrazide, C7H6Cl2N2O, are linked into simple chains by a single N-H center dot center dot center dot O hydrogen bond, while in the isomeric compound 2,4-dichloro-benzo-hydrazide, the molecules are linked by N-H center dot center dot center dot N and N-H center dot center dot center dot O hydrogen bonds into complex sheets comprising an inner polar layer sandwiched between two non-polar layers. In 4-amino-2-chloro-benzohydrazide monohydrate, C7H8ClN3O center dot H2O, the components are linked into a three-dimensional framework by a combination of O-H center dot center dot center dot O, O-H center dot center dot center dot N, N-H center dot center dot center dot N and N-H center dot center dot center dot O hydrogen bonds, and in 2-nitro-benzohydrazide, C7H7N3O3, a three-dimensional framework is formed by a combination of N-H center dot center dot center dot N and N-H center dot center dot center dot O hydrogen bonds.</p