Two new coordination polymers differentiated by CH⋯O hydrogen bonding — synthesis and crystal structure of [(oxa)M(DPA)]

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.

Synthetic, structural and magnetic implications of introducing 2,2′-dipyridylamide to sodium-ferrate complexes

Establishing transamination as an efficient method to access novel heterobimetallic complexes, this study provides magnetic and structural insights of 2,2-dipyridylamide based sodium ferrate complexes.

(Di-2-pyridylamine-κ2N,N′)[hydrotris(3,5-diphenylpyrazol-1-yl-κN2)borato]nickel(II) bromide dichloromethane monosolvate

In the title compound, [Ni(C₄₅H₃₄BN₆)(C₁₀H₉N₃)]Br·CH₂Cl₂, the Ni^II atom is five-coordinated by the tridentate hydro­tris­(3,5-diphenyl­pyrazol­yl)borate ligand and a bidentate di-2-pyridyl­amine ligand in a distorted square-pyramidal geometry. In the crystal, inter­molecular N—H⋯Br and C—H⋯Br hydrogen bonds link the Ni complex cations and the Br⁻ ions, forming a chain along the c axis.

catena-Poly[[[diaqua-(di-2-pyridylamine-κN,N')nickel(II)]-μ-fumarato-κO:O] tetra-hydrate]

In the crystal structure of the title compound, {[Ni(C(4)H(2)O(4))(C(10)H(9)N(3))(H(2)O)(2)]·4H(2)O}(n), zigzag chains are built up from cis-[Ni(dpya)(H(2)O)(2)](2+) cations (dpya is di-2-pyridylamine) linked by bis-monodentate coordinated bridging fumarate ligands. The Ni(II) atom is coordinated by one chelating dpya ligand, two aqua ligands in trans positions and two monodentate fumarate ligands in cis positions in the form of a deformed octa-hedron. The water mol-ecules, O atoms of the fumarate carboxyl-ate groups and the amine group of the dpya ligand are involved in an extended network of intra- and inter-molecular O-H⋯O hydrogen bonds. Moreover, π-π inter-actions between the pyridine rings of the dpya ligand contribute to the stability of the structure. Two of the five uncoordinated water molecules are half-occupied.

Synthesis, Structure, and Magnetic Properties of (A)[FeIII(oxalate)Cl2] (A = Alkyl Ammonium Cations) with Anionic 1D [FeIII(oxalate)Cl2]- Chains

The use of alkyl ammonium cations resulted in four compounds of (A)[FeIII(ox)Cl2] (A = Et3NH+ (1a, 1b), Me4N+ (2), and n-Bu4N+ (3); ox = oxalate), whose structures and magnetic properties were characterized. In all cases, the metal Fe(III) ions are six-coordinated by four oxygen atoms from two bischelating oxalate ligands and the two terminal Cl- ions in the cis position. Thus they form similar anionic 1D [FeIII(ox)Cl2]- chains. The chains are separated by alkyl ammonium cations in the lattice, and the cation size seems to control the interchain separation and packing patterns in the solid. A parallel arrangement of the [FeIII(ox)Cl2]- chains is observed for 1a, 2, and 3, while a crossed one is observed for 1b, which is a polymorph of 1a. Magnetic studies reveal the antiferromagnetic intrachain interactions in all compounds. The last three compounds, 1b, 2, and 3, show spin canting below 14.5, 9.5, and 3.8 K, respectively. The dipolar interaction over the interchain distance is proposed to be the result of 3D magnetic ordering in the materials.

A coordination π–π framework exhibits spontaneous magnetization

A pi-pi scaffolding framework that was assembled as a one-dimensional chain structure comprising alternating Delta- and Lambda-iron(II) chiral building units, [Fe(II)(Delta)Fe(II)(Lambda)(ox)2(phen)2]n, reveals spontaneous magnetization that gives rise to pronounced hysteresis loops below 10 K.

Transition Metal-Organic Polycarboxylate Coordination Polymer Chemistry. Hydrothermal Synthesis and Structural Characterization of a One-Dimensional Coordination Polymer [Fe(bzta)2(ox)]n (bzta = benzotriazole, ox = oxalato)

Complex [Fe(bzta)2(ox)]n (1) was synthesized from K3[Fe(ox)3]·3H2O and benzotriazole. Single-crystal X-ray diffraction study of complex 1 has established a novel structure containing several kinds of secondary bonding interactions. All these interactions make it display a three-dimensional supramolecular network.