5-Methyl-1,2,3,3a-tetra-hydro-benzo[e]pyrrolo-[2,1-b][1,3]oxazepin-10(5H)-one.

The asymmetric unit of the title compound, C(13)H(15)NO(2), the main product of a photoreaction, contains two crystallographically independent mol-ecules. In both mol-ecules, the conformation of the seven-membered ring is twist sofa and that of the five-membered rings is envelope. In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O hydrogen bonds.

Poly[dimethyl-ammonium [aquadi-µ(2)-oxalato-samarate(III)] trihydrate].

In the title complex, {(C(2)H(8)N)[Sm(C(2)O(4))(2)(H(2)O)]·3H(2)O}(n), the Sm(III) atom is chelated by four oxalate ligands and one water mol-ecule forming a distorted tricapped trigonal-prismatic geometry. Each oxalate ligand chelates to two Sm(III) atoms, generating a three-dimensional anionic network with cavities in which the ammonium cations and lattice water mol-ecules reside. Various O-H⋯O, N-H⋯O and C-H⋯O hydrogen-bonding inter-actions further stablize the crystal structure.

Poly[dimethyl-ammonium [aquadi-µ(2)-oxalato-yttriate(III)] trihydrate].

The title complex, {(C(2)H(8)N)[Y(C(2)O(4))(2)(H(2)O)]·3H(2)O}(n), was obtained accidentally under hydro-thermal conditions. The Y(III) atom is chelated by four oxalate ligands and one water mol-ecule resulting in a distorted tricapped trigonal-prismatic geometry. Each oxalate ligand bridges two Y(III) atoms, thus generating a three-dimensional network with cavities in which the ammonium cations and lattice water mol-ecules reside. Various O-H⋯O and N-H⋯O hydrogen-bonding inter-actions stabilize the crystal structure. The title complex is isotypic with the Eu and Dy analogues.

5-p-Tolyl-1,2,3,3a-tetra-hydro-benzo[e]pyrrolo-[2,1-b][1,3]oxazepin-10(5H)-one.

The structure of the title compound, C(19)H(19)NO(2), contains a seven-membered ring, which is fused to one five- and one six-membered ring, and carries a tolyl substituent. The two benzene rings are oriented relative to each other at a dihedral angle of 86.90 (7)°. In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O hydrogen bonds.

(3aR*,5R*)-5-(4-Chloro-phen-yl)-1,2,3,3a-tetra-hydro-benzo[e]pyrrolo-[2,1-b][1,3]ox-azepin-10(5H)-one.

The title compound, C(18)H(16)ClNO(2), is the main product of a photoreaction. The two benzene rings make a dihedral angle of 86.40 (2)° with each other. The 1,3-oxazepine C atom to which the 4-chloro-phenyl group is attached and the C atom of the 4-chloro-phenyl group attached to the 1,3-oxazepine ring are chiral C atoms, but the crystal is a racemate in which the enanti-omers are linked by a pair of weak inter-molecular C-H⋯O hydrogen bond, forming an inversion dimer.

catena-Poly[[(1,10-phenanthroline-κN,N')cadmium(II)]-µ-oxalato-κO,O:O,O].

In the title complex, [Cd(C(2)O(4))(C(12)H(8)N(2))](n), the Cd(II) atom has a distorted octa-hedral coordination, defined by four O atoms from two symmetry-related oxalate ligands and by two N atoms from a bidentate 1,10-phenanthroline ligand. Each oxalate ligand bridges two Cd(II) atoms, generating a zigzag chain structure propagating along [100]. The packing of the structure is consolidated by non-classical C-H⋯O hydrogen-bonding inter-actions.

Bis(melaminium) tartrate dihydrate.

In the title compound, 2C(3)H(7)N(6) (+)·C(4)H(4)O(6) (2-)·2H(2)O, in which the complete anion is generated by crystallographic twofold symmetry, there are O-H⋯O, N-H⋯O and N-H⋯N hydrogen-bonding inter-actions between neighbouring moieties, forming layers parallel to the bc plane. In addition, π-π contacts [centroid-centroid distance = 3.6541 (9) Å] between the six-membered rings of the melamine cations are observed.