Bis­(azido‐κN)[(6R,7S,8S,14S)‐(–)‐sparteine‐κ2N,N′]copper(II)

In the title compound, [Cu(N₃)₂(C₁₅H₂₆N₂)], the chiral alkaloid (−)‐l‐sparteine (Sp) acts as a bidentate ligand, with two azide ligands occupying the remaining coordination sites, forming a distorted CuN₄ tetrahedron. The dihedral angle between the N_Sp—Cu—N_Sp and N_azide—Cu—N_azide planes is 55.3 (2)°. Principal dimensions include Cu—N_Sp = 2.011 (6) and 2.025 (5) Å, and Cu—N_azide = 1.939 (6) and 1.934 (7) Å. The mid‐point of the N_Sp⋯N_Sp line does not lie exactly in the N_azide—Cu—N_azide plane, but is tilted towards one of the N_Sp atoms by 0.026 Å.     

Bis[1,1‐di­methyl­biguanide(1–)‐κ2N2,N5]copper(II) monohydrate

The crystal structure of the title compound, [Cu(C₄H₁₀N₅)₂]·H₂O, contains two independent copper N,N‐di­methyl­biguanide complex units, each with square‐planar coordination of the Cu atom by four N atoms. The two complexes have different symmetry, with one Cu atom lying on an inversion centre and the other on a twofold rotation axis. The Cu—N bond lengths are 1.923 (2) and 1.950 (2) Å in the centrosymmetric complex, and 1.928 (2) and 1.938 (2) Å in the non‐centrosymmetric complex. The crystal structure is stabilized by N—H⋯O, O—H⋯N and N—H⋯N hydrogen bonds; each water mol­ecule forms four hydrogen bonds involving three different Cu complexes.     

Dibromo(pyridoxal semicarbazone‐κ3N1,O3,O3′)copper(II)

The title compound, di­bromo(3‐hydroxy‐5‐hydroxy­methyl‐2‐methyl‐4‐pyridine­carbox­aldehyde semicarbazone‐κ³N¹,O³,O^3′)copper(II), [CuBr₂(C₉H₁₂N₄O₃)], consists of discrete complex units with the tridentate pyridoxal semicarbazone ligand as a zwitterion in an almost planar configuration. The Cu^II ions are in a distorted square‐pyramidal coordination, with the equatorial Br atom at a distance of 2.4017 (6) Å and the apical Br atom at a distance of 2.6860 (6) Å.     

(2,2′‐Biquinoline‐κ2N,N′)bis(nitrato‐κ2O,O′)copper(II)

In the title monomer, [Cu(NO₃)₂(C₁₈H₁₂N₂)], the six‐coordinated Cu^II atom lies on a twofold axis which bisects one of the ligands (a chelating biquinoline) and duplicates the remaining ligand, a chelating nitrate. The latter binds in a very asymmetric way, consistent with a Jahn–Teller distortion in the coordination polyhedron which, due to the triple chelation, is extremely distorted and difficult to describe in terms of any regular model.     

Diaquabis(quinoxaline‐2‐carboxylato‐κ2N1,O)copper(II)

In the title compound, [Cu(C₉H₅N₂O₂)₂(H₂O)₂], the Cu^II ion lies on an inversion centre and has an elongated centrosymmetric octahedral environment, equatorially trans‐coordinated by two N,O‐bidentate quinoxaline‐2‐carboxylate ligands and axially coordinated by two water O atoms. Symmetry‐related molecules are linked by strong O—H...O hydrogen bonds, involving the uncoordinated carboxyl O atom of the carboxylate group and the coordinated water molecules, to form a two‐dimensional network. Weak intermolecular C—H...N interactions also stabilize the crystal structure.     

Bis(acesulfamato‐κ2N3,O4)bis­(2‐amino­pyrimidine‐κN1)copper(II)

In the crystal structure of the title compound, bis­(2‐amino­pyrimidine‐κN¹)bis­[6‐meth­yl‐1,2,3‐oxathia­zin‐4(3H)‐one 2,2‐dioxide(1−)‐κ²N³,O⁴]copper(II), [Cu(C₄H₄NO₄S)₂(C₄H₅N₃)₂], the first mixed‐ligand complex of acesulfame, the Cu^II centre resides on a centre of symmetry and has an octa­hedral geometry that is distorted both by the presence of four‐membered chelate rings and by the Jahn–Teller effect. The equatorial plane is formed by the N atoms of two amino­pyrimidine (ampym) ligands and by the weakly basic carbonyl O atoms of the acesulfamate ligands, while the more basic deprotonated N atoms of these ligands are in the elongated axial positions with a strong misdirected valence. The crystal is stabilized by pyrimidine ring stacking and by inter­molecular hydrogen bonding involving the NH₂ moiety of the ampym ligand and the carbon­yl O atom of the acesulfamate moiety.     

A novel titanium–μ‐O–zirconium complex: bis(μ‐methyliminodiethanolato‐1κ3O,N,O′;1:2κ2O)(methyliminodiethanolato‐2κ3O,N,O′)dipropanolato‐1κO,2κO‐titanium(IV)zirconium(IV)

The title compound, [TiZr(C₅H₁₁NO₂)₃(C₃H₇O)₂], contains three methyl­imino­diethano­late ligands, two in different μ‐oxo bridging coordination modes and one bound only to the Ti atom. The Ti and Zr atoms have distorted octahedral and pentagonal–bipyramidal coordinations, respectively, which share edges. As well as some conformational disorder in the carbon chains, there is chemical disorder at one Ti site, with a mix of n‐ and isopropanolate ligands.