Synthesis, crystal structure, and DNA binding of a new oxalato-bridged binuclear zinc(II) complex

A new binuclear Ni(II) complex, an effective A3-coupling catalyst in solvent-free condition

A newly binuclear nickel(II) complex, [Ni2(en)4(ox)](ClO4)2 (1) (where en = ethylenediamine, and ox = oxalate), has been isolated from a reaction of NiCl2·6H2O, ethylenediamine, ammonium oxalate and sodium perchlorate in water and its crystal structure has been determined by X-ray crystallography and infra-red techniques. Compound 1 was successfully employed to promote the one-pot reaction of aldehydes, amines and acetylenes for the construction of corresponding propargylamines under solvent-free media with fine yields. Further studies reveal this catalytic system can be refreshed and used again in five runs.

Towards oxalate-bridged iron(ii), cobalt(ii), nickel(ii) and zinc(ii) complexes through oxotris(oxalato)niobate(v): an open air non-oxidizing synthetic route

Oxalate release by [Nb^VO(C₂O₄)₃]^3– is a suitable strategy to prepare oxalate-bridged dimetal(ii) complexes that exhibit antiferromagnetic interactions.

μ-Oxalato-κO,O:O,O-bis-[diaqua-(2,2'-bipyridyl-κN,N')zinc] bis-[2-(1H-benzotriazol-1-yl)acetate] hexa-hydrate

The asymmetric unit of the title compound, [Zn₂(C₂O₄)(C₁₀H₈N₂)₂(H₂O)₄](C₈H₆N₃O₂)₂·6H₂O, contains one half of the centrosymmetric binuclear cation, one anion and three water mol­ecules. In the cation, the oxalate ligand bridges two Zn^II ions in a bis-bidentate fashion, so each Zn^II ion is coordinated by two O atoms from the oxalate ligand, two N atoms from two 2,2′-bipyridine ligands and two water mol­ecules in a distorted octa­hedral arrangement. The mean planes of the oxalate and 2,2′-bipyridine ligands form a dihedral angle of 80.0 (1)°. An extensive three-dimensional hydrogen-bonding network formed by classical O—H⋯O and O—H⋯N inter­actions consolidates the crystal packing.

μ-Oxalato-bis-[bis-(2,2'-bipyridine)-manganese(II)] bis(perchlorate) 2,2'-bipyridine solvate

The unit cell of the title compound, [Mn(2)(C(2)O(4))(C(10)H(8)N(2))(4)](ClO(4))(2)·C(10)H(8)N(2), consists of a binuclear cation, two perchlor-ate anions, and one solvent 2,2'-bipyridine (bpy) mol-ecule. In the complex cation [Mn(2)(C(2)O(4))(C(10)N(2)H(8))(4)](2+), two Mn(II) atoms are bridged by a bis-(bidentate) oxalate ligand, each Mn(II) atom being further coordinated by two bpy ligands in a distorted octa-hedral geometry. The distance between the two six-coordinated metal atoms is 5.583 (1) Å. π-π stacking inter-actions [inter-planar distances between bpy rings = 3.739 (1) Å] are essential to the supramolecular assembly. There are extensive inter-ionic C-H⋯O inter-actions between the cations and between the cation and anion. Three of the four perchlorate O atoms are disordered over two sets of sites with occupancy ratios of 0.852 (6):0.148 (6).