Chemistry

In the title compound, C 12 H 13 N 3 O 4 S, the nitro group is slightly twisted [6.58 (11) ] from the benzene ring plane. The morpholine ring adopts a chair form. In the crystal, intermolecular N-HÁ Á ÁO hydrogen bonds link the molecules into chains along [110]. There are alsocontacts [centroidcentroid distance = 3.8301 (11) Å ] and C-HÁ Á Á interactions to stack neighbouring benzene rings and link the chains into a three-dimensional network. C-HÁ Á ÁO and C-HÁ Á ÁS interactions are also observed.

The dihedral angle between the two benzene rings in the title compound, C 15 H 15 NO 2 , is 65.28 (12). The crystal structure is stabilized by N-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds, leading to the formation of supramolecular chains along the aaxis direction.

The molecule of the title compound, C 14 H 16 N 2 O 2 , is located on a crystallographic twofold rotation axis. The central O-CC -O bridge adopts a gauche conformation. One of the amine H atoms is disordered over two equally occupied positions. The crystal structure is stabilized by N-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonds.

The title compound, C 22 H 28 N 2 O 6 , crystallizes with four halfmolecules in the asymmetric unit: each molecule is located about a crystallographic inversion centre. The central methylene groups of two molecules are disordered over two sets of equally occupied sites. The crystal packing is characterized by sheets of molecules parallel to (114).

In the title compound, C 17 H 11 NO 4 , the dihedral angle between the two benzene rings is 8.66 (3). The nitro group is twisted by 4.51 (9) out of the plane of the aromatic ring to which it is attached. The presence of intermolecular C-HÁ Á ÁO contacts in the crystal structure leads to the formation of chains along the c axis.

The crystal structure of the title compound, C14H15NO·0.5H2O, features N—H...O and O—H...N hydrogen bonds between the amino group and water molecule of crystallization, which generate a chain along the c axis. The water molecule lies on a twofold rotation axis. A C—H...π interaction is observed between the phenyl and aniline rings. The angle between the mean planes of the phenyl rings is 72.51 (7)°.

The title compound, C 14 H 11 NO 4 , crystallizes with two molecules in the asymmetric unit. The major conformational difference between these two molecules is the dihedral angle between the aromatic rings, namely 36.99 (5) and 55.04 (5). The nitro groups are coplanar with the phenyl rings to which they are attached, the ON -CC torsion angles being À1.9 (3) and 1.0 (3) in the two molecules. Related literature For background to the applications of aromatic esters containing nitro groups in their aromatic rings, see: Jefford & Zaslona (1985); Jefford et al. (1986); Schauble et al. (1971). For related structures, see: Adams & Morsi (1976); Shibakami & Sekiya (1995). Experimental Crystal data C 14 H 11 NO 4 M r = 257.24 Orthorhombic, P2 1 2 1 2 1 a = 11.4748 (7) Å b = 14.3608 (8) Å c = 14.5944 (9) Å V = 2405.0 (2) Å 3 Z = 8 Mo K radiation = 0.11 mm À1 T = 173 K 0.48 Â 0.43 Â 0.42 mm Data collection Stoe IPDS II two-circle diffractometer Absorption correction: none 8396 measured reflections 2536 independent reflections 2233 reflections with I > 2(I) R int = 0.032

The two phenyl rings of the biphenyl unit of the title compound, C 18 H 13 NO 3 , are almost coplanar [dihedral angle 6.70 (9) ]. The nitrophenyl ring, on the other hand, is significantly twisted out of the plane of the these two rings, making dihedral angles of 68.83 (4) with the middle ring and 62.86 (4) with the end ring. The nitro group is twisted by 12.1 (2) out of the plane of the phenyl ring to which it is attached. Related literature The title compound is a precursor of amine which is a useful curing agent of epoxy resins. For the properties and applications of epoxy resins, see:

The title compound, C 17 H 18 N 2 O 6 , crystallizes with two molecules in the asymmetric unit. In both molecules, one of the CC bonds of the pentamethylene chain connecting the two aromatic rings is in a trans conformation and another displays a gauche conformation. The aromatic rings within each molecule are nearly coplanar [dihedral angles = 3.36 (9) and 4.50 (9) ] and the nitro groups are twisted slightly out of the planes of their attached rings [dihedral angles = 8.16 (3)/ 6.6 (2) and 4.9 (4)/3.8 (3) ]. Related literature For general background and synthetic aspects of thermally stable polymers, see:

The title compound, C12H17NO4, features an almost planar molecule (r.m.s. deviation for all non-H atoms = 0.070 Å). All methylene C—C bonds adopt an antiperiplanar conformation. In the crystal structure the molecules lie in planes parallel to (1\overline{1}2) and the packing is stabilized by O—H...O hydrogen bonds.