A cofacial binuclear copper(II) complex with a bridging 1,4-dithiane ligand

Abstract

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

Hierarchical assembly of discrete copper(ii) metallo-structures from pre-assembled dinuclear (bis-β-diketonato)metallocycles and flexible difunctional co-ligands

“…[{Cu 2 (L 1 ) 2 } 2 (thiomorph) 4 ]•3thiomorph. Both the C (18) and C (21)-containing tertiary butyl groups are disordered over two positions and each was modelled with identical thermal parameters. The encapsulated thiomorpholine ligand is disordered across a symmetry position in two equal occupancy positions.…”

“…3 We, and others, have found that ligands incorporating more than one β-diketone motif react with selected metal ions to yield an array of metallo-supramolecular architectures with the products in many instances exhibiting a significant degree of predictability. 1,3,10 Structures generated with these ligands include helicates, [11][12][13][14] tetrahedra, 15,16 boxes, 17 capsules 18 and an unprecedented universal 3-ravel; 14 for example, the well defined coordination vectors of ligands L 1-3 produce neutral planar metallocyclic species of type [M 2 (L 1 ) 2 ] (1) 11,13,[19][20][21] [M 3 (L 2 ) 3 ] (2) 16,22 and the larger [M 3 (L 3 ) 3 ] (3) 23,24 upon reaction with selected divalent transition metals.…”

Redetermination of the crystal structure of 1,4-dithiane, at 200 K – Analysis of intermolecular forces, C4H8S2

“…Incorporating two donor atomsinto a cyclic compound offers an additional level of confinement that might give rise to interestingc oordination patterns.1 ,4-Dichalcogeno derivatives of cyclohexane appeared as interesting bondingp artnersa st he variation in conformation could easily turn them from mono-into bidentate ligands. 1,4-Dithiane was chosen to act as astarting point in an upcoming study about the coordination behaviour of the aforementionedc ompounds as it has been found to realize avariety of coordination modes: it has been found to act as ap urely monodentate ligand [1], as a monodentate, m 1 bridging ligand [2],asamonodentate, m 2 bridging ligand [3] and as bidentate chelating ligand [4].I ts crystal structurehas been reported earlier, however,atroom temperature only with [5]and without [6] hydrogen atom positions localized or as aprivate communication at low temperature [7]sothat no discussion of metricalparameters is at hand forthese latter conditions. The present study is intended to close this gap and to enable the comparison of metrical parameters in envisioned coordination compounds whose structures will be determined at low temperature as well.…”