In the biologically active title compound, C26H26O5, the pyran ring of the chromene unit adopts a half-chair conformation. The C=C double bond of the propenone unit exhibits a trans conformation and the carbonyl group is syn conformation to the double bond. The dihedral angle between the benzene ring and the benzopyran-one moiety is 31.54 (4)°. The mol-ecular structure is stabilized by an intra...

By combining quantum-mechanical analysis of small model peptides and statistical surveys of high-resolution protein structures, a systematic conformational dependence of bond lengths in polypeptide backbones has been unveiled which involves both the peptide bond (C-O and C-N) and those bonds centred on the C(α) atom. All of these bond lengths indeed display a systematic variability in the ψ ang...

In the title compound C18H20N2O2, the morpholine ring adopts a chair conformation with the exocyclic N-C bond in an equatorial orientation. The N atom of the morpholine ring and the C atom of the carbonyl group are in an anti conformation about the central C-C bond [torsion angle = -162.92 (11)°] and the dihedral angle between the planes of the benzene ring and the pyridine ring is 83.30 (5)°. ...

In the title compound, C17H11Cl2NO, the dihedral angle between the planes of the naphthalene ring system and the benzene ring is 28.88 (11)°. The main twist in the mol-ecule occurs about the N-Cb (b = benzene ring) bond, as indicated by the C=N-Cb-Cb torsion angle of 31.0 (4)°. An intra-molecular O-H⋯N hydrogen bond closes an S(6) ring. In the crystal, inversion dimers linked by pairs of very w...

In the title compound, C(17)H(14)BrClN(4)O(2), the pyrazole ring is almost coplanar with the benzene ring [dihedral angle = 0.5 (2)°], whereas the pyrazole ring is close to perpendicular to the 3-chloro-pyridine ring [dihedral angle = 73.7 (2)°]. An intra-molecular C-H⋯O hydrogen bond occurs. The dominant inter-action in the crystal packing is an N-H⋯N hydrogen bond, which generates a chain alo...

In the title compound, C(13)H(10)N(2)O(5)S, the C=O bond in the -SO(2)-NH-CO- segment is anti to the meta-nitro group in the benzoyl ring, while the N-C bond has gauche torsions with respect to the S=O bonds. The molecule is twisted at the N atom with a dihedral angle of 79.9 (2)° between the sulfonyl benzene ring and the -SO(2)-NH-CO- segment. Furthermore, the dihedral angle between the benzen...

In the crystal structure of the title compound, C(13)H(11)NO(3)S, the conformation of the N-H bond in the C-SO(2)-NH-C(O)-C segment is anti to the C=O bond. The molecule is twisted at theN atom with a dihedral angle of 86.5(1)° between the sulfonyl benzene ring and the -SO(2)-NH-C=O segment. Furthermore, the dihedral angle between the two benzene rings is 80.3(1)°. The crystal structure feature...

In the cation of the title mol-ecular salt, C13H20NO(+)·C7H5ClNO2 (-), the five-membered ring adopts a twisted conformation about one of the C-N bonds. The exocyclic N-C bond has an equatorial orientation. The dihedral angle between the five-membered ring (all atoms) and the benzene ring is 76.56 (19)°. In the anion, the dihedral angle between the carboxyl-ate group and the benzene ring is 18.5...

In the crystal structure of the title compound, C14H14N2O4S, the N-H bond is syn to the ortho-nitro group in the sulfonyl benzene ring and anti to the ortho- and syn to the meta-methyl groups in the aniline ring. The mol-ecule is twisted at the S-N bond with a torsion angle of 71.41 (18)°. The dihedral angle between the planes of the benzene rings is 51.07 (8)°. In the crystal, pairs of N-H⋯Osu...

The molecule of the title compound, C(32)H(48)O(4)P(2)S(2), has 2 symmetry, the mid-point of the S-S bond being located on a twofold rotation axis. The two tetra-hedral P units are linked by a S-S bond with a P-S-S-P torsion angle is 131.19 (6)°. The dihedral angle between two phenyl rings is 12.66 (13)°. The cyclo-hexane ring of the menthoxyl group displays a chair conformation. Weak inter-mol...