Azide, water and adipate as bridging ligands for Cu(II) : synthesis, structure and magnetism of (μ4-adipato-κ-O)(μ-aqua)(μ-azido-κN1,N1)copper(II) monohydrate

The Distinguished Scientist Fellowship Program (DSFP) at King Saud University is gratefully acknowledged. The authors are grateful to the Algerian MESRS (Ministère de l’Enseignement Supérieur et de la Recherche Scientifique), the Université Ferhat Abbas Sétif 1, the KSU DSFP program and the Spanish MINECO (CTQ2014-52758-P and MAT2014-56143-R) and the Generalitat Valenciana (PrometeoII/2014/076) for financial support.The synthesis, characterization, single crystal structure and magnetic properties of the compound [(CuN3(OH2))2(adp)]n (1) are presented, in which adp stands for the adipate(2-) anion. This compound consists of layers containing chains of six-coordinated Cu(II) ions; the chains are connected by μ4adipate anions. The magnetically interesting part of the compound is the Cu(II) chain, built from 3 bridging ligands, i.e. a water ligand, an azide anionic ligand bridging by using a terminal N atom to connect 2 Cu(II) ions, and one symmetrically bridging carboxylato group of adipate; the other end of the tetradentate adipate anions symmetrically connect the chains, forming the layers. From the magnetic point of view the compound is considered as a Cu(II) chain with a quite unusual, symmetrical water bridge, the μ-syn-syn carboxylate and the μ-N3 bridge. The bridging water also hydrogen bonds to a terminal N of a nearby azido ligand. Magnetic susceptibility measurements show that 1 presents moderate ferromagnetic intrachain interactions (Jchain = +38.4 cm-1) with a metamagnetic behaviour for the inter-chain interaction with a critical field of 0.7 T.PostprintPeer reviewe

Bis(2,2′-bi-1H-imidazole)­copper(II) bis­(1,1,3,3-tetra­cyano-2-eth­oxy­propenide)

In the title compound, [Cu(C6H6N4)2](C9H5N4O)2, the Cu2+ ion (site symmetry ) is coordinated by two N,N′-bidentate 2,2′-biimidazole (H2biim) ligands, generating a square-planar CuN4 geometry. The dihedral angle between the aromatic rings in the ligand is 0.70 (9)°. In the polynitrile 1,1,3,3-tetra­cyano-2-eth­oxy­propenide (tcnoet) anion, the C—N, C—C and C—O bond lengths indicate extensive electronic delocalization. An alternative description for the metal-ion geometry is an extremely distorted CuN6 octa­hedron, with two N-bonded tcnoet anions completing the coordination. In the crystal, the components are linked by N—H⋯N and C—H⋯N inter­actions

Redetermination of the crystal structure of bis(tri-2-pyridylamine)iron(II) bis(perchlorate), and a new refinement of the isotypic nickel(II) analogue : treatment of the perchlorate anion disorder

The authors are indebted to the Algerian DG–RSDT (Direction Générale de la Recherche Scientifique et du Développement Technologique) and Université Ferhat Abbas Sétif 1 for financial support.The redetermination of the structure of the title compound, [Fe(C15H12N4) 2](ClO4)2, (I), confirms the structure previously reported [Kucharski it et al. (1978a). Aust. J. Chem. 31 , 53-56], but models the perchlorate over four sets of atomic sites, rather than using just one set of sites as in the original report. The supramolecular assembly, not reported previously, takes the form of a complex three-dimensional framework built from C—H···O hydrogen bonds. The isotypic nickel(II) analogue, [Ni(C15H12N4)2](ClO4)2, (III), has been refined using the original data set [Wang it et al. (2011). Acta Cryst. E 67 , m78], again using a four-component disorder model for the anion, rather than a two-component model as in the original report, leading to more satisfactory Cl—O distances and O—Cl—O angles.Publisher PDFPeer reviewe

Coexistence of Spin Canting and Metamagnetism in a One-Dimensional Mn(II) Compound Bridged by Alternating Double End-to-End and Double End-On Azido Ligands and the Analog Co(II) Compound

Two new compounds of general formula [M(N3)2(dmbpy)] in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized and characterized structurally and magnetically. The structures consist of zig-zag polymeric chains with alternating bis-µ(azide-N1)2M and bis-µ(azide-N1,N3)2M units in which the cis-octahedrally based coordination geometry is completed by the N,N’-chelating ligand dmbpy. The molecular structures are basically the same for each metal. The Mn(II) compound has a slightly different packing mode compared to the Co(II) compound, resulting from their different space groups. Interestingly, relatively weak interchain interactions are present in both compounds and this originates from π–π stacking between the dmbpy rings. The magnetic properties of both compounds have been investigated down to 2 K. The measurements indicate that the manganese compound shows spin-canted antiferromagnetic ordering with a Néel temperature of TN = 3.4 K and further, a field-induced magnetic transition of metamagnetism at temperatures below the TN. This finding affords the first example of an 1D Mn(II) compound with alternating double end-on (EO) and double end-to-end (EE) azido-bridged ligands, showing the coexistence of spin canting and metamagnetism. The cobalt compound shows a weak ferromagnetism resulting from a spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 16.2 K

Crystal structure of tetraaqua[2-(pyridin-2-yl)-1H-imidazole-kappa N-2(2),N-3]iron(II) sulfate

In the title compound, [Fe(C8H7N3)(H2O)(4)]SO4, the central Fe-II ion is octahedrally coordinated by two N atoms from the bidentate 2-(pyridin-2-yl)-1H-imidazole ligand and by four O atoms of the aqua ligands. The largest deviation from the ideal octahedral geometry is reflected by the small N-Fe-N bite angle of 76.0 (1)degrees. The Fe-N coordination bonds have markedly different lengths [2.1361 (17) and 2.243 (2) angstrom], with the shorter one to the pyrimidine N atom. The four Fe-O coordination bond lengths vary from 2.1191 (18) to 2.1340 (17) angstrom. In the crystal, the cations and anions are arranged by means of medium-strength O-H center dot center dot center dot O hydrogen bonds into layers parallel to the ab plane. Neighbouring layers further interconnect by N-H center dot center dot center dot O hydrogen bonds involving the imidazole fragment as donor group to one sulfate O atom as an acceptor. The resulting three-dimensional network is consolidated by C-H center dot center dot center dot O, C-H center dot center dot center dot pi and pi-pi interactions

Synthesis, structure, and magnetic properties of a dinuclear antiferromagnetically coupled iron(II) complex

The authors acknowledge the Algerian DGRSDT (Direction Générale de la Recherche Scientifique et du Développement Technologique) and Université Ferhat Abbas Sétif 1 for financial support.A new dinuclear Fe(II) complex with the general formula [Fe2(1,4-tpbd)(dca)4(H2O)2] ( 1 ) (in which 1,4-tpbd = N,N,N′,N′-tetrakis(2-pyridylmethyl)benzene-1,4-diamine; dca = dicyanamide, [N(CN)2]−), has been prepared under hydrothermal conditions and fully characterized by elemental analysis, infrared spectroscopy, X-ray diffraction, and magnetic measurements. The compound crystallizes in the triclinic system and P-1 space group with Z = 1 and the following unit cell parameters: a = 8.165(5) Å, b = 10.236(5) Å, c = 13.105(5) Å, α = 81.421(5)°, β = 78.810(5)°, γ = 72.941(5)°, and V = 1022.2(9) Å3. The Fe(II) ions are six-coordinated, in distorted octahedral fashion, by three N atoms of tpbd ligand, one water oxygen atom and two N atoms of two dicyanamide anions. The intra-dinuclear Fe⋯Fe distance via the bridged μ2-tpbd ligand is 8.293(8) Å. In the molecular arrangement, the combination of OH⋯N and CH⋯N hydrogen bonds links the title complex to form a three-dimensional supramolecular structure. Magnetic susceptibility measurements (2–300 K) show that 1 presents weak antiferromagnetic exchange between the two nearest Fe2+ ions with the coupling constant J = −1.05 cm−1.PostprintPeer reviewe

Crystal structure and Hirshfeld surface analysis of tris(2,2′-bipyridine)nickel(II) bis(1,1,3,3-tetracyano-2-ethoxypropenide) dihydrate

International audienceThe title compound, [Ni(C10H8N2)3](C9H5N4O)2·2H2O, crystallizes as a racemic mixture in the monoclinic space group C2/c. In the crystal, the 1,1,3,3-tetracyano-2-ethoxypropenide anions and the water molecules are linked by O—H...N hydrogen bonds, forming chains running along the [010] direction. The bpy ligands of the cation are linked to the chain via C—H...π(cation) inter­actions involving the CH3 group. The inter­molecular inter­actions were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots

Bis[tris(pyridin-2-yl)amine]iron(II) tris(dicyanomethylidene)methanediide

FS gratefully acknowledges the Algerian MESRS (Ministere de l’Enseignement Superieur et de la Recherche Scientifique), the DGRSDT (Direction Generale de la Recherche Scientifique et du Developpement Technologique), as well as the Universite Ferhat Abbas Setif 1 for financial support.In the title compound, [Fe{(C5H4N)3N}2][C{C(CN)2}3], both ions lie across centres of inversion, with the anion being statistically disordered over two sets of atomic sites having equal occupancy. The cation and anion have approximate 3 and 32 symmetry, respectively, and the Fe---N bond lengths indicate low-spin FeII. A combination of two-centre C—H···N and three-centre C—H···(N)2 hydrogen bonds link the ions into complex sheets. Several low-occupancy water molecules are present, whose H atoms could not be located: accordingly, the reflection data were subjected to the SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9-18].Publisher PDFPeer reviewe