Key indicators: single-crystal X-ray study; T = 120 K; mean (C-C) = 0.005 Å; R factor = 0.050; wR factor = 0.110; data-to-parameter ratio = 12.7.The molecule of (-1,4-dithiane-2 , lies on an inversion center, with a CuÁ Á ÁCu distance of 8.130 (1) Å . The Cu II centers have square-pyramidal coordination geometry, with Cu-O distances in the range 1.905 (2)-1.925 (2) Å and a Cu-S distance of 2.8088 (10) Å . The host binuclear complex is distorted from a rectangular shape. The inversion symmetry of the molecule requires that the two coordination planes be parallel. However, they are 'slipped': the normals to the two coordination planes at the Cu atoms are 1.865 (1) Å apart. Another measure of this 'slipping' is provided by the four CH 2 groups, whose C atoms form a parallelogram with interior angles of 87.2 (3) and 92.8 (3) . The two chelate rings tilt differently from the coordination plane, with one Cu atom lying only 0.0131 (5) Å out of one C 3 O 2 mean plane, but 0.4416 (5) Å out of the other. Those two chelate planes form a dihedral angle of 11.2 (4) . This relatively large deviation is believed to be due to the large size of the 1,4-dithiane guest. CommentOur group has previously prepared binuclear metal complexes derived from polydentate liands, which have been shown to intramolecularly bind bridging substrate molecules, similar to those produced by several other flexible binucleating macrocycles. This work was undertaken in an attempt to associate and quantify the binding between di-sulfur bases and their previously studied nitrogen analogues, see Related Literature section.The molecule is centrosymmetric, and inclusion of the 1,4-dithiane molecule organizes the host such that the Cu···Cu distance, 8.130 (1) Å, is longer than in complexes with other guests, see Related Literature section. Several distortions take place in this organization. The Cu 2 (NBA) 2 unit is not rectangular, but slipped such that the four CH 2 groups (C6, C17 and

In the title compound, C12H18O5, the ring has a chair conformation, with endocyclic torsion angle magnitudes in the range 47.7 (3)–66.7 (2)°. The OH group donates an intermolecular hydrogen bond to a C=O group with an O...O distance of 2.791 (3) Å, forming chains.

Key indicators: single-crystal X-ray study; T = 100 K; mean (C-C) = 0.002 Å; R factor = 0.041; wR factor = 0.113; data-to-parameter ratio = 18.9.The title compound, C 11 H 16 O 4 , was produced when pentane-2,4-dione (acacH) was treated with formaldehyde in a ca 2.16:1 molar ratio. The compound exists in the solid state as the keto tautomer, although the enol tautomer also exists in solution. The C O distances are in the range 1.2097 (18)-1.2169 (18) Å . Intermolecular C OÁ Á ÁC O interactions exist, the shortest having a CÁ Á ÁO distance of 3.378 (2) Å . organic compounds o3108 # 2007 International Union of Crystallography

No abstract