ABSTRACT
The title compound, C23H24N2O9, is a tetra-substituted pyrrolidine derivative with a twisted conformation, with the twist evident in the C-C bond bearing the adjacent acet-yloxy substituents. These are flanked on one side by a C-bound 4-meth-oxy-phen-yl group and on the other by a methyl-ene group. The almost sp 2-N atom [sum of angles = 357°] bears a 4-nitro-benzyl-oxycarbonyl substituent. In the crystal, ring-methyl-ene-C-Hâ¯O(acet-yloxy-carbon-yl) and methyl-ene-C-Hâ¯O(carbon-yl) inter-actions lead to supra-molecular layers lying parallel to (01); the layers stack without directional inter-actions between them. The analysis of the calculated Hirshfeld surfaces indicates the combined importance of Hâ¯H (42.3%), Hâ¯O/Oâ¯H (37.3%) and Hâ¯C/Câ¯H (14.9%) surface contacts. Further, the inter-action energies, largely dominated by the dispersive term, point to the stabilizing influence of Hâ¯H and Oâ¯O contacts in the inter-layer region.
ABSTRACT
The title compound, C13H19NO8, is based on a tetra-substituted pyrrolidine ring, which has a twisted conformation about the central C-C bond; the Cm-Ca-Ca-Cme torsion angle is 38.26â (15)° [m = methyl-carboxyl-ate, a = acet-yloxy and me = methyl-ene]. While the N-bound ethyl-carboxyl-ate group occupies an equatorial position, the remaining substituents occupy axial positions. In the crystal, supra-molecular double-layers are formed by weak methyl- and methyl-ene-C-Hâ¯O(carbon-yl) inter-actions involving all four carbonyl-O atoms. The two-dimensional arrays stack along the c axis without directional inter-actions between them. The Hirshfeld surface is dominated by Hâ¯H (55.7%) and Hâ¯C/Câ¯H (37.0%) contacts; Hâ¯H contacts are noted in the inter-double-layer region. The inter-action energy calculations point to the importance of the dispersion energy term in the stabilization of the crystal.
ABSTRACT
The title pyrrolidine compound, C18H23NO7, is a tetra-substituted species in which the five-membered ring has a twisted conformation with the twist occurring in the C-C bond bearing the adjacent acet-yloxy substituents; the Cm-Ca-Ca-Cp torsion angle is -40.76â (18)° [m = methyl-ene, a = acet-yloxy and p = phen-yl]. The N atom, which is sp 2-hybridized [sum of bond angles = 359.4°], bears an ethyl-carboxyl-ate substitutent and is connected to a methyl-ene-C atom on one side and a carbon atom bearing a 4-meth-oxy-phenyl group on the other side. Minor disorder is noted in the ethyl-carboxyl-ate substituent as well as in one of the acet-yloxy groups; the major components of the disorder have site occupancies of 0.729â (9) and 0.62â (3), respectively. The most notable feature of the mol-ecular packing is the formation of helical, supra-molecular chains aligned along the b-axis direction whereby the carbonyl-O atom not involved in a disordered residue accepts C-Hâ¯O inter-actions from methyl-ene-H and two-C atom separated methine-H atoms to form a six-membered {â¯HCCCHâ¯O} synthon.
ABSTRACT
In the title compound, C12H12N2O4, the di-hydro-pyrrole ring is almost planar (r.m.s. deviation = 0.0049â Å) and is nearly coplanar with the adjacent C2O2 residue [dihedral angle = 4.56â (9)°], which links to the 4-nitro-benzene substituent [dihedral angle = 4.58â (8)°]. The mol-ecule is concave, with the outer rings lying to the same side of the central C2O2 residue and being inclined to each other [dihedral angle = 8.30â (7)°]. In the crystal, supra-molecular layers parallel to (10-5) are sustained by nitro-benzene-C-Hâ¯O(carbon-yl) and pyrrole-C-Hâ¯O(nitro) inter-actions. The layers are connected into a three-dimensional architecture by π(pyrrole)-π(nitro-benzene) stacking [inter-centroid separation = 3.7414â (10)â Å] and nitro-Oâ¯π(pyrrole) inter-actions.
ABSTRACT
In the title compound, C28H34N2O5, the adjacent ester and nitro-benzene substituents are connected via an intra-molecular methyl-ene-C-Hâ¯π(nitrobenzene) inter-action and the mol-ecule approximates to a U-shape. The di-hydro-pyrrole ring (r.m.s. deviation = 0.003â Å) is almost co-planar with the carboxyl-ate residue [Cm-N-C1-Oc (m = methine, c = carbox-yl) torsion angle = 1.8â (4)°] but is orthogonal to the 4-meth-oxy-benzene ring [dihedral angle = 84.34â (17)°]. In the crystal, methyl-ene-C-Hâ¯O(carbon-yl) inter-actions lead to linear supra-molecular chains along the b-axis direction, which pack without directional inter-actions between them. The analysis of the calculated Hirshfeld surface points to the importance of weak inter-atomic Hâ¯H, Oâ¯H/Hâ¯O and Câ¯H/Hâ¯C contacts in the crystal.
ABSTRACT
In the title furan-carboxamide derivative, C11H8N2O4, the benzene and furan rings are rotated from the mean plane of the central fragment by 2.68â (5) and 7.03â (4)°, respectively. The nitro group forms a dihedral angle of 10.15â (5)° with the adjacent benzene ring. In the crystal, mol-ecules are linked by weak C-Hâ¯O inter-actions, forming helical chains running along [010].
ABSTRACT
In the title mol-ecule, C13H7N3O8, the phenyl and benzene rings are rotated from the mean plane of the central ester group by 18.41â (9) and 81.80â (5)°, respectively. The dihedral angle between the rings is 80.12â (14)°. In the crystal, mol-ecules are linked by weak C-Hâ¯O inter-actions, forming helical chains along [010].
ABSTRACT
In the title mol-ecule, C(10)H(11)BrClNO, there is a twist between the mean plane of the amide group and the benzene ring [C(=O)-N-C-C torsion angle = -27.1â (3)°]. In the crystal, inter-molecular N-Hâ¯O and weak C-Hâ¯O hydrogen bonds link the mol-ecules into chains along [010].
ABSTRACT
In the title mol-ecule, C(11)H(14)BrNO, there is twist between the mean plane of the amide group and the benzene ring [C(=O)-N-C C torsion angle = -31.2â (5)°]. In the crystal, inter-molecular N-Hâ¯O and weak C-Hâ¯O hydrogen bonds link mol-ecules into chains along [100]. The methyl group H atoms are disordered over two sets of sites with equal occupancy.