Koordinationspolymere 1, 2-Dithiooxalato- und 1, 2-Dithioquadratato-Komplexe. Synthese und Strukturen von [BaCr2(bipy)2(1, 2-dtox)4(H2O)2], [Ni(cyclam)(1, 2-dtsq)]·2DMF, [Ni(cyclam)Mn(1, 2-dtsq)2(H2O)2]·2H2O und [H3O][H5O2][Cu(cyclam)]3[Cu2(1, 2-dtsq)3]2

Abstract

Inhaltsübersicht. 1,2-Dithiooxalat-und 1,2-Dithioquadratationen haben je ein Paar harter und weicher Donoratome und können damit koordinationspolymere Verbindungen bilden. Über die Strukturen vier solcher Verbindungen wird berichtet: In [BaCr 2 -(bipy) 2 (1,2-dtox) 4 (H 2 O) 2 ] sind zehnfach von Sauerstoffatomen koordinierte Bariumionen über Paare von Cr(bipy)(1,2-dtox) 2 -Einheiten kettenförmig verbunden. [Ni(cyclam)(1,2-dtsq)]·2DMF hat ebenfalls eine Kettenstruktur. Der Ni···Ni-Abstand beträgt 8.532 Å . In [Ni(cyclam)Mn(1,2-dtsq) 2 (H 2 O) 2 ]·2H 2 O liegen Zick-

Origin of Weak Magnetic Coupling in a Dimanganese(II) Complex Bridged by the Tetrathiafulvalene-Tetrathiolate Radical

“…The distortion is likely due to the chelate rings of the TPA ligand, and similar distortions are observed in another dinuclear Mn complex with TPA capping ligands . The Mn–S bond lengths range from 2.470(2) to 2.548(2) Å, which are similar to those reported in other Mn­(II)–dithiolene structures. − The central C–C bond lengths of the bridging TTFtt moiety are 1.36(2) and 1.37(2) Å, which are also similar to the values in Sn­(IV) and Ni­(II) complexes bridged by TTFtt 3–• . TTFtt π–π stacking interactions are not observed in 1 , contrary to previously reported square planar Ni­(II) complexes, which may reasonably be attributed to the steric effect from the chelating TPA ligands.…”

Lights and shadows in the challenge of binding acyclovir, a synthetic purine-like nucleoside with antiviral activity, at an apical–distal coordination site in copper(II)-polyamine chelates

“…in the cation [Cu(cyclam)(H 2 O) 2 ] 2+ [38][39][40][41] or related compounds where the trans-apical ligands are other molecular solvents (N,Ndimethylformamide [42,43] and acetonitrile [44][45][46]) or anionic ligands such as cyanide [47] and azide [48,49]. Nevertheless, square based pyramidal (type 4 + 1) complexes [50] and the square-planar [Cu(cyclam)] 2+ cation [51] have also been reported. According to these data, the Cu(II)-cyclam chelate could be considered as an appropriate receptor for the apical coordination of one (or even two) acv ligand(s), coordinated via its N7-donor and assisted by an intramolecular interligand interaction (cyclam)N-H⋯O6(acv).…”

Crystal structure of poly[μ2-aqua-aqua(μ2-4-nitro-2,5,6-trioxo-1,2,5,6-tetrahydropyridin-3-olato)hemi-μ4-oxalato-barium(II)]

“…1), the tenfold coordination of the Ba1 atom (Table 1) is formed by the O2, O5, O1 and O2 atoms of two 4-nitro-2,3,5,6tetraoxopyridine-4-ide anions (L), the O7, O8 and O7A atoms of two oxalate anions, and the O9, O9A and O10 atoms of water molecules. The Ba-O bond lengths fall in the range 2.698 (3)-2.978 (3) Å , which is typical for ten-coordinate barium complexes containing oxalate anions (Viciano-Chumillas et al, 2010;Heinl et al, 2002;Marinescu et al, 2005;Belombe et al, 2003Belombe et al, , 2012Larsson, 2001;Bouayad et al, 1995;Iveson et al, 2011). The L anion has a flattened skeleton.…”