5a-Butyl-1,3,8,10-tetra-chloro-7,13-bis-(4-nitro-benzo-yl)-5a,6a,12a,12b-tetra-hydro-7H,13H-thieno[2,3-b:4,5-b']bis-(1,4-benzoxazine).

The title compound, C(34)H(24)Cl(4)N(4)O(8)S, is a linear penta-cyclic system formed of two substituted benzoxazinyl groups fused to 2-n-butyl-tetra-hydro-thio-phene. The oxazine ring, which is fused to the n-butyl-substituted side of the thio-phene ring, is in a boat conformation. The other fused oxazine ring and the tetra-hydro-thiene ring are each in an envelope conformation.

2-(1,2,3,4-Tetra-hydro-phenanthren-1-yl-idene)malononitrile.

In the title complex, C(17)H(12)N(2), the non-aromatic six-membered ring adopts an envelope conformation. The dihedral angle between the eight-membered plane containing the malononitrile group and the aromatic system is 25.88 (4)°.

A 3,5-dinitro-benzoyl derivative of a stereoisomer of glycerol menthonide.

The title compound, [(2S,5R,6S,9R)-6-isopropyl-9-methyl-1,4-dioxaspiro-[4.5]dec-2-yl]methyl 3,5-dinitro-benzoate, C(20)H(26)N(2)O(8), was synthesized as part of a study of three-carbon stereochemical systems. The crystallographic assignment of the absolute stereochemistry is consistent with having started with (-)-menthone, the acetal carbon is R and the secondary alcohol is S.

4,5-Dichloro-2H-1,3-oxazine-2,6(3H)-dione.

In the title compound, C(4)HCl(2)NO(3), the essentially planar (maximum deviation = 0.023 Å for the ring O atom) mol-ecules form N-H⋯O hydrogen bonds between mol-ecules lying about inversion centers, forming eight-membered rings with an R(2) (2)(8) motif in graph-set notation.

4-Bromo-2H-1,3-oxazine-2,6(3H)-dione.

The title compound, C(4)H(2)BrNO(3), is one of a series of three substituted oxauracils prepared as precursors in the preparation of 1-aza-1,3-butadienes. Although each structure has identical potential for N-H⋯O inter-molecular hydrogen bonds, each forms a distinctive inter-molecular network. In the title compound, there are two independent mol-ecules in the asymmetric unit, with a non-crystallographic twofold screw-like relationship between them.

4-Methyl-2H-1,3-oxazine-2,6(3H)-dione.

In the title compound, C(5)H(5)NO(3), the planar (maximum deviation = 0.075 Å for the ring O atom) mol-ecules form N-H⋯O hydrogen bonds in a zigzag chain (C-O⋯N bond angle ≃ 140°) between glide-related mol-ecules.

Redetermination of cis-diaqua-diglycolato-zinc(II).

The title complex, [Zn(C(2)H(3)O(3))(2)(H(2)O)(2)], was prepared and the crystal structure determined as part of a (67)Zn solid state nuclear magnetic resonance study. In the title complex, the Zn atom has a disorted octa-hedral coordination comprising two bidentate glycolate ligands and two water mol-ecules. The water mol-ecules are cis to each other; one is trans to a carboxyl-ate O atom and the other trans to an alcohol O atom.

Correlation of a Solution-State Conformational Change between Mercuric Chloride Complexes of Tris[(2-(6-methylpyridyl))methyl]amine with X-ray Crystallographic Structures.

Solution-state NMR and X-ray crystallography were used to investigate the complexation of HgCl(2) by the potentially tetradentate ligand tris[(6-methyl-2-pyridyl)methyl]amine (TLA) in acetonitrile. A change in the ligand conformation as a function of the metal-to-ligand ratio could be indirectly monitored through large changes in (3)J((1)H(199)Hg) to the methylene protons at -40 degrees C. The solution-state NMR were correlated with two solid-state structures.