A new polymorph of aqua-bis-(1,10-phenanthroline-κ(2) N,N')copper(II) dinitrate.

The title mol-ecule, [Cu(C12H8N2)2(H2O)](NO3)2, is a new polymorph of a compound which up to now has been reported to crystallize space groups in C2/c and Cc. The crystal studied was twinned by non-merohedry (final BASF factor of 0.40043) with the structure being solved and refined in P-1. The Cu(II) atom is coordinated by four N atoms from two 1,10-phenanthroline ligands and an O atom from a water mol-ecule in an approximate trigonal-bipyramidal geometry. Discrete entities of one cation and two nitrate anions are formed by water-nitrate O-H⋯O hydrogen bonds. The components are further assembled into a three-dimensional network by C-H⋯O hydrogen bonds.

Bis(2,2'-bipyridyl-κ(2) N,N')chloridonickel(II) nitrate trihydrate.

In the title hydrated salt, [NiCl(C10H8N2)2](NO3)·3H2O, the Ni(2+) ion is coordinated by two 2,2'-bipyridyl (2,2'-bpy) ligands and a chloride ion in a trigonal-bipyramidal geometry. The chloride ion occupies an equatorial site and the dihedral angle between the 2,2'-bpy ring systems is 72.02 (6)°. In the crystal, the components are linked by C-H⋯O and O-H⋯O hydrogen bonds and aromatic π-π stacking inter-actions [shortest centroid-centroid separation = 3.635 (2) Å], generating a three-dimensional network.

Bis(acetyl-acetonato-κ(2)O,O')bis-(pyridine-κN)nickel(II) dihydrate.

The title compound, [Ni(C(5)H(7)O(2))(2)(C(5)H(5)N)(2)]·2H(2)O, crystallizes with two half-mol-ecules in the asymmetric unit. The Ni(II) ion of each unique complex mol-ecule lies on an inversion centre and has an octa-hedral coordination geometry. The crystal structure features weak O-H⋯O hydrogen bonds, which form chains running parallel to the a axis.

Poly[[diaqua-bis-(µ2-4,4'-bipyrid-yl)cobalt(II)] dinitrate tetra-hydrate].

The title compound, {[Co(C10H8N2)2(H2O)2](NO3)2·4H2O} n , (C10H8N2 = 4,4'-bipyridine = 4,4'-bpy) is a layered coordination polymer built up from a cationic square grid extending in (101) enclosing uncoordinating nitrate ions and water mol-ecules. The Co(II) ion has site symmetry 2 and one of the 4,4'-bpy ligands is generated by twofold symmetry [two N atoms and two C atoms lie on the rotation axis and the dihedral angle between the pyridine rings is 45.66 (5)°]. The other 4,4'-bpy ligand is generated by a crystallographic inversion center. The Co(II) ion exhibits a slightly distorted octa-hedral coordination geometry defined by two O atoms of two coordinating water mol-ecules and four N atoms from four bridging 4,4'-bpy ligands. The structure is consolidated by O-H⋯O, C-H⋯O and C-H⋯N hydrogen bonds.

Bis[2-(5-methyl-sulfanyl-1,3,4-oxadiazol-2-yl-κN(3))phenolato-κO(1)]copper(II).

In the title complex, [Cu(C(9)H(7)N(2)O(2)S)(2)], the Cu(II) ion, located on an inversion center, adopts an N(2)O(2) square-planar coord-ination. The 2-(5-methyl-sulfanyl-1,3,4-oxadiazol-2-yl)phenolate ligand is chelated to the central Cu(II) ion in an N,O-bidentate manner.

N,N,N',N'-Tetra-methyl-phthalamide.

The title compound, C(12)H(16)N(2)O(2), crystallized from toluene with two independent mol-ecules in the asymmetric unit. The dihedral angles between the amide groups and the benzene ring are 60.87 (11) and 54.08 (11)° in one independent molecule and 60.13 (11) and 64.64 (11) in the other. The crystal structure features weak C-H⋯O hydrogen bonds and C-H⋯π inter-actions.

Aqua-bis-[N'-(1,3-dithio-lan-2-ylidene)-2-hy-droxy-benzohydrazidato(0.5-)-κ(2)N',O]sodium(I).

The title compound, [Na(C(10)H(9.5)N(2)O(2)S(2))(2)(H(2)O)], is a mol-ecular sodium complex with N'-(1,3-dithio-lan-2-yl)-2-hy-droxy-benzohydrazide ligands with the negative charge spread evenly over both, and a water mol-ecule. The Na(I) ion coordination is distorted trigonal-bipyramidal, formed by two N and three O atoms, with the Na(I) ion lying on a twofold rotation axis. Intra-molecular N-H⋯O hydrogen bonds occur. Mol-ecules pack as discrete units and the crystal packing is stabilized by strong O-H⋯O hydrogen bonds, which give rise to chains along [010]; the chains are inter-linked by strong O-H⋯O hydrogen bonds.

Synthesis, crystal structure and Hirshfeld surface analysis of aqua-(3-meth-oxy-cinnamato-κO)bis-(1,10-phenanthroline-κ2 N,N')cobalt(II) nitrate.

The title compound, [Co(C10H9O3)(C12H8N2)2(H2O)]NO3 (I), crystallizes in the triclinic space group P with a monomeric [Co(3-meo-cin)(phen)2(H2O)]+ cation and a nitrate anion (3-meo-cin = 3-meth-oxy cinnamic acid) in the asymmetric unit. The CoII ion is coordinated by four N atoms from two 1,10-phenanthroline ligands and two O atoms, the first from a meth-oxy cinnamate ligand and the second from a coordinated water mol-ecule, forming a distorted octa-hedral geometry. Discrete entities of the cation and nitrate anion are formed by water-nitrate O-H⋯O and phen-nitrate C-H⋯O hydrogen bonds. The components are further assembled into chains along the c-axis direction. Layers are than formed by slipped π-π stacking inter-actions parallel to the bc plane. The inter-molecular inter-actions in the crystal structure were qu-anti-fied and analysed using Hirshfeld surface analysis.

Bis(2,2'-bi-1H-imidazole)-copper(II) bis-(1,1,3,3-tetra-cyano-2-eth-oxy-propenide).

In the title compound, [Cu(C(6)H(6)N(4))(2)](C(9)H(5)N(4)O)(2), the Cu(2+) ion (site symmetry ) is coordinated by two N,N'-bidentate 2,2'-biimidazole (H(2)biim) ligands, generating a square-planar CuN(4) geometry. The dihedral angle between the aromatic rings in the ligand is 0.70 (9)°. In the polynitrile 1,1,3,3-tetra-cyano-2-eth-oxy-propenide (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 CuN(6) octa-hedron, with two N-bonded tcnoet anions completing the coordination. In the crystal, the components are linked by N-H⋯N and C-H⋯N inter-actions.

Synthesis, structure and magnetic properties of a series of dinuclear heteroleptic Zn2+/Ln3+ Schiff base complexes: effect of lanthanide ions on the slow relaxation of magnetization.

We report an investigation on the synthesis, structure and magnetic properties of a series of heteroleptic Zn2+/Ln3+ complexes of the general formula [ZnLClLn(o-van)(H2O)(NO3)]·H2O (H2L = N,N'-bis(3-methoxysalicylidene)-1,2-diaminoethane; o-van = o-vanillinate; Ln = Tb (1), Dy (2), Er (3)). All the compounds exhibit a slow relaxation of their magnetization and the dysprosium analogue shows one of the highest anisotropic barriers for ZnDy complexes.

A luminescent Schiff-base heterotrinuclear Zn2Dy single-molecule magnet with an axial crystal field.

We report here the synthesis and investigation into the magnetic properties of a luminescent trinuclear Zn2Dy Schiff-base complex that exhibits a zero-field single-molecule magnet behaviour. Magneto-structural correlation confirms that the axial crystal-field is generated by the phenoxide moieties while the characteristic Dy3+-based luminescence is observed.

Synthesis, structure and magnetic investigations of dinuclear lanthanide complexes based on 2-ethoxycinnamate.

A series of dinuclear lanthanide complexes incorporating the 2-ethoxycinnamate ligand have been synthesized and characterized using elemental analyses, infra-red spectroscopy, X-ray diffraction and magnetic measurements. Depending on the nature of the lanthanide ion, three different isostructural series of respective formulas, [Ln(L)3(DMSO)(H2O)]2 (Ln = Ce (1), Nd (2)), [Ln(L)3(DMSO)x(DMF)y(H2O)]2 (Ln = Gd (3), Dy (5) and Er (6)) and [Tb(L)3(DMF)(H2O)]2 (4) have been obtained. Investigations of their magnetic properties reveal a genuine single-molecule magnet behaviour observed for the dysprosium based compound 5, while a field-induced slow relaxation of the magnetization is found for compounds 1, 2 and 3.

A new copper(II) coordination polymer containing chains of interconnected paddle-wheel antiferromagnetic clusters.

The construction of supramolecular architectures based on inorganic-organic coordination frameworks with weak noncovalent interactions has implications for the rational design of functional materials. A new crystalline binuclear copper(II) one-dimensional polymeric chain, namely catena-poly[[[tetrakis(µ-4-azaniumylbutanoato-κ2O:O')dicopper(II)(Cu-Cu)]-µ-chlorido-[diaquadichloridocopper(II)]-µ-chlorido] bis(perchlorate)], {[Cu3Cl4(C4H9NO2)4(H2O)2](ClO4)2}n, was obtained by the reaction of 4-aminobutyric acid (GABA) with CuCl2·2H2O in aqueous solution. The structure was established by single-crystal X-ray diffraction and was also characterized by IR spectroscopy and magnetic measurements. The crystal structure consists of [{Cu2(GABA)4}{CuCl4(H2O)2}]+ cations and isolated perchlorate anions. Two symmetry-related CuII centres are bridged via carboxylate O atoms into a classical paddle-wheel configuration, with a Cu...Cu distance of 2.643 (1) Å, while bridging Cl atoms complete the square-pyramidal geometry of the metal atoms. The Cl atoms connect the paddlewheel moieties to a second CuII atom lying on an octahedral site, resulting in infinite helical chains along the c axis. The packing motif exhibits channels containing free perchlorate anions. The crystal structure is stabilized by hydrogen bonds between the perchlorate anions, the coordinated water molecules and the ammonium groups of the polymeric chains. The magnetic analysis of the title compound indicates a nontrivial antiferromagnetic behaviour arising from alternating weak-strong antiferromagnetic coupling between neighbouring CuII centres.

Cinnamic acid derivative rare-earth dinuclear complexes and one-dimensional architectures: synthesis, characterization and magnetic properties.

Discrete and extended architectures based on the association of lanthanide ions with two derivatives of cinnamic acid (2-methoxycinnamic acid and 3-methoxycinnamic acid) have been synthesized and characterized by IR spectroscopy, elemental analyses, X-ray diffraction and magnetic measurements. The use of the 2-methoxycinnamic ligand enables the synthesis of a series of dinuclear complexes (Ce3+ (1), Nd3+ (2), Gd3+ (3), Dy3+ (4)), while the presence of 3-methoxycinnamic acid induces the formation of one-dimensional coordination polymers (Ce3+ (5), Nd3+ (6), Dy3+ (7)). Investigations of the magnetic properties of the complexes reveal that they all exhibit field-induced slow relaxation of the magnetisation, mainly induced by Raman and direct relaxation processes.

Tris(2,2'-bipyridine)iron(II) bis(1,1,3,3-tetracyano-2-ethoxypropenide) dihydrate: chiral hydrogen-bonded frameworks interpenetrate in three dimensions.

In the title compound, [Fe(C10H8N2)3](C9H5N4O)2·2H2O, the chiral cations lie across twofold rotation axes in the space group C2/c. The anions and the water molecules are linked by two independent O-H···N hydrogen bonds to form C2(2)(8) chains, and these chains are linked by the cations via C-H···N and C-H···O hydrogen bonds to form two interpenetrating three-dimensional frameworks, each of which contains only one enantiomeric form of the chiral cation.

1,1'-Diethyl-4,4'-bipyridine-1,1'-diium bis(1,1,3,3-tetracyano-2-ethoxypropenide): multiple C-H...N hydrogen bonds form a complex sheet structure.

In the title salt, C14H18N2(2+) · 2C9H5N4O(-), the 1,1'-diethyl-4,4'-bipyridine-1,1'-diium dication lies across a centre of inversion in the space group P21/c. In the 1,1,3,3-tetracyano-2-ethoxypropenide anion, the two independent -C(CN)2 units are rotated, in conrotatory fashion, out of the plane of the central propenide unit, making dihedral angles with the central unit of 16.0(2) and 23.0(2)°. The ionic components are linked by C-H...N hydrogen bonds to form a complex sheet structure, within which each cation acts as a sixfold donor of hydrogen bonds and each anion acts as a threefold acceptor of hydrogen bonds.

Mg2Ru2Cl10O.16H2O.

Mg2Ru2Cl10O.16H2O {dimagnesium mu-oxo-bis[pentachlororuthenate(IV)] hexadecahydrate} crystallizes in the monoclinic system (space group P2(1)/c). The structure consists of layers of [Ru2Cl10O]4- anions, [Mg(H2O)6]2+ cations and water molecules stacked along the a axis. Only the O atom bonded to Ru occupies the 2a site with -1 symmetry. All the other atoms occupy general 4e sites. The crystal structure is stabilized by O-H...O and O-H...Cl interactions.

Synthesis, structure and magnetic properties of chiral and nonchiral transition-metal malates.

Carboxylate-bridged complexes of transition metals, M(II)=Mn(II), Fe(II), Co(II), Ni(II), Zn(II), were synthesised by reaction of M(II) salts with dl-malate and L-malate under hydrothermal conditions. These complexes form four series of compounds, which have been fully characterised structurally, thermally and magnetically. The crystal structures of the new chiral compounds, [Mn(L-mal)(H(2)O)] (1), [Fe(L-mal)(H(2)O)] (2), [Co(L-mal)(H(2)O)] (3) and [Zn(L-mal)(H(2)O)] (4) as well as those of the bimetallic analogues [Mn(0.63)Co(0.37)(L-mal)(H(2)O)] (5) and [Mn(0.79)Ni(0.21)(L-mal)(H(2)O)] (6) have been solved by single-crystal X-ray diffraction. The six L-malate monohydrates crystallise in the chiral space group P2(1)2(1)2(1) and consist in a three-dimensional network of metal(II) centres in octahedral sites formed by oxygen atoms. These structures were compared to those of the chiral trihydrate compounds [Co(L-mal)(H(2)O)]2 H(2)O (7), [Ni(L-mal)(H(2)O)]2 H(2)O (8) and [Co(0.52)Ni(0.48)(L-mal)(H(2)O)]2 H(2)O (9), which exhibit helical chains of M(II) centres, and those of dl-malate dihydrates [Co(dl-mal)(H(2)O)]H(2)O (10) and [Ni(dl-mal)(H(2)O)H(2)O (11) and trihydrate [Mn(L-mal)(H(2)O)]2 H(2)O (12) highlighting the great flexibility of the coordination by the malate ligand. UV/Vis spectroscopic results are consistent with octahedral coordination geometry of high-spin transition-metal centres. Extensive magnetic characterisation of each homologous series indicates rather weak coupling interaction between paramagnetic centres linked through carboxylate bridges. Curie-like paramagnetic, antiferromagnetic, ferromagnetic or weak ferromagnetic behaviour is observed and discussed on the basis of the structural features. The bimetallic compounds 5 and 6 represent new examples of chiral magnets.