Adel Beghidja

An approach to chiral magnets using α-hydroxycarboxylates

Carboxylate-bridged complexes of transition metals, MII = MnII, FeII, CoII, NiII, CuII, were synthesized by reaction of MII salts with (R)-mandelic acid ((R)-2-hydroxyphenylacetic acid), methoxymandelic acid (racemic) (2-methoxyphenylacetic acid) and (R)-malic acid ((R)-2-hydroxybutanedioic acid) under hydrothermal conditions. A wide variety of structures has been obtained, with various dimensionalities: 3D networks when the malic diacid is used, 2D networks with the mandelic acid, 1D isolated chains organised in planes for the Co and Cu compounds with MeOmandelic acid and monomers for the Ni analogue. These complexes have been fully characterized structurally and magnetically. During the reaction process, the (R)-mandelic ligand undergoes a racemisation reaction but the compounds obtained with (R)-malic acid are chiral and exhibit metal-centred circular dichroism. Extensive magnetic characterization of all compounds indicates rather weak coupling interactions between paramagnetic centres linked through carboxylate bridges. Curie-like paramagnetic, antiferromagnetic, ferromagnetic or weak ferromagnetic behaviour was observed and is discussed on the basis of the structural features. The bimetallic compounds Mn0.63Co0.37(R)-malate monohydrate (12) and Mn0.79Ni0.21(R)-malate monohydrate (13) are new examples of chiral magnets.

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.

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.

Bis[3‐acetyl‐6‐methyl‐2H‐pyran‐2,4(3H)‐dionato]bis­(dimethyl sulfoxide)copper(II)

Laboratoire d0Electrochimie des Matériaux Moléculaires et Complexes, Département de Génie des Procédés, Faculté des Science de l0Ingénieur, Université Farhat Abbes de Setif, DZ-19000 Sétif, Algeria, Département de Chimie, Faculté des Sciences et Sciences de l0Ingénieur, Université A. Mira de Béjaia, Route Targua Ouzmour 06000 Béjaia, Algeria, and Laboratoire de Chimie Moléculaire, du Contrôle de l0Environnement et de Mesures Physico-Chimiques, Département de Chimie, Faculté des Sciences, Université Mentouri 25000, Constantine, Algeria

A new polymorph of aqua­bis­(1,10-phenanthroline-κ2N,N′)copper(II) dinitrate

The title molecule, [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 CuII atom is coordinated by four N atoms from two 1,10-phenanthroline ligands and an O atom from a water molecule 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.

N,N,N′,N′-Tetra­methyl­phthalamide

The title compound, C12H16N2O2, crystallized from toluene with two independent molecules 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 interactions.

Naphthalene-1,5-diammonium dichloride

In the title compound, C10HI2N2+·2CI−, the naphthalene-1,5-diammonium ion lies on an inversion center; the asymmetric unit contains half of the cation and one Cl− anion. The structure can be described as consisting of alternating layers of C10HI2N2+ and CI− ions perpendicular to the a axis. The structure contains N—H⋯Cl hydrogen bonds, which build up a two-dimensional network.

Bis(2,2′-bipyridyl-κ2N,N′)chloridonickel(II) nitrate trihydrate

In the title hydrated salt, [NiCl(C10H8N2)2](NO3)·3H2O, the Ni2+ 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 interactions [shortest centroid–centroid separation = 3.635 (2) Å], generating a three-dimensional network.

Bis(acetyl­acetonato-κ2O,O′)bis­(pyridine-κN)nickel(II) dihydrate

The title compound, [Ni(C5H7O2)2(C5H5N)2]·2H2O, crystallizes with two half-molecules in the asymmetric unit. The NiII ion of each unique complex molecule lies on an inversion centre and has an octahedral coordination geometry. The crystal structure features weak O—H⋯O hydrogen bonds, which form chains running parallel to the a axis.

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(C10H9.5N2O2S2)2(H2O)], is a molecular sodium complex with N′-(1,3-dithiolan-2-yl)-2-hydroxybenzohydrazide ligands with the negative charge spread evenly over both, and a water molecule. The NaI ion coordination is distorted trigonal–bipyramidal, formed by two N and three O atoms, with the NaI ion lying on a twofold rotation axis. Intramolecular N—H⋯O hydrogen bonds occur. Molecules 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 interlinked by strong O—H⋯O hydrogen bonds.