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Research has been conducted on Fe(II) methylphosphonate. The crystal growth, X-ray single crystal structure and magnetic studies of this derivative are discussed.

Research demonstrates the synthesis and characterization of a new 'weak ferromagnet' iron(II) phenylphosphonate. The crystal structure reveals a lamellar structure with alternating inorganic and organic layers with phenyl groups dispersed on both ends of the stack and exhibit antiferromagnetic properties.

Results describe synthesis of a novel one-dimensional supramolecular compound containing iron(III) ions and TCNQ acceptor. Crystal structural data reveal semiconductor behavior of the compound.

A study on the synthesis, crystal structure and chemical properties of three different metallic fragments with (NiLN)(super 2+) and (TCNQ)(sub 2)(super 2-) is presented. The metallic fragments are (Ni(dien)2)(super 2+), (Ni(trien))(super 2+) and (Ni(cyclam))(super 2+). Results show that the interaction between TCNQ and the metallic fragments depends on the metal environment in the transition metal center. Hydrogen bonds between the TCNQ nitriles and the amine groups of the metal fragments stabilizes the supramolecular architecture.

Copper(II) halides coordinate with various polyfunctional sulfur-rich ligands to produce copper(II), copper(I) and mixed valence derivatives. Sulfur-rich donor, 1, 3-dithiolane-2-thione, gives only Cu(I) derivatives. Introduction of an additional CH(2) group in 1,3-dithiolane-2 thione ring leads to mixed valence derivatives. X-ray and EPR techniques are used for the analyses of structural and magnetic properties of these complexes.

The platinum(II) dithiosquarate anion is combined with bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) to obtain a new salt of formula (BEDT-TTF)2Pt(S2C4O2)2. The complex is then studied for its crystal and molecular structure by x-ray diffraction crystallography. Results show that the new compound exhibits a diamagnetic behavior and has energy bands which can be assigned to the electronic excitations of the platinum(II) dithiosquarate anion.

The synthesis and characterization of a new arene pi-complex (perylene)3(Bi4Br12) are described. The complex was prepared by the reaction of perylene with anhydrous bismuth bromide. Analysis showed that the structure of the complex is determined by bismuth-arene interactions and the pi-pi interactions between perylene molecules.

The X-ray single-crystal structure of the layered hybrid organic-inorganic compound is determined. A benefit of this is represented by the synthesis of a molecule-based compound that is polar and magnetic.

The new metal--organic compound nickel(II) 3,4;9,10-perylenediimide bis-phosphonate pentahydrate, i.e. Ni2[(PDI-BP)-(H20)2]-3H20 (1), has been synthesized and its structural and magnetic properties have been studied. Reaction of 3,4;9,10-perylenediimide bis-phosphonate (PDI-BP, hereafter) ligand and nickel chloride in water resulted in the precipitation of a red and poorly crystalline solid (1). As the solid shows a poor crystalline organization of aggregates, the energy dispersive X-ray diffraction analysis (EDXD) technique has been used to obtain short-range order structural information of the single nanoaggregates by radial distribution function analysis. The overall structure of the compound is characterized by layers containing perylene planes shifted in the direction perpendicular to the stacking axes in such a way that only the outer rings overlap. The edges of the perylene planes are connected to the phosphonate groups through an imido group. The oxygen atoms of the [--PO3]2 group and those of the water molecules are bonded to the nickel ions resulting in a [NiO6] octahedral coordination sphere. The Ni--O bond lengths are 0.21 ± 0.08 nm and the Ni--O--Ni angles of aligned moieties are 95 ± 2°. The oxygen atoms of the water molecules and the nickel atoms are nearly planar and almost perpendicular to the perylene planes forming chains of edge-sharing octahedra. Tlie magnetic properties of (1) show tlie presence of ¡ntiachain ferromagnetic Ni--Ni interactions and a long-range ferromagnetic order below 21 K with a canting angle and with a spin glasslike behavior due to disorder in the inorganic layer. Hysteresis cycles show a coercive field of ca. 272 mT at 2 K that decreases as the temperature is increased and vanishes at ca. 20 K. [ABSTRACT FROM AUTHOR]

The reaction of nickel chloride with phenyl phosphonic acid under hydrothermal conditions resulted in the isolation of yellow-green single crystals of Ni[(C6H5PO3)(H2O). The structure of the compound has been solved by X-ray single-crystal diffraction studies. Ni[(C6H5PO3)(H2O)] crystallizes in the orthorhombic space group Pmn21 and is isostructural with the Mn(Il), Fe(ll), and Co(ll) analogues. It presents the typical features of the hybrid 2D structures, consisting of alternating inorganic and organic layers. The former are formed by six-coordinated nickel(ll) ions bridged by oxygen atoms into the layers. The inorganic layers are capped by the phenyl phosphonate groups, with phenyl groups of two adjacent ligands forming a hydrophobic bilayer region, and van der Waals contacts are established between them. The magnetic properties investigated by means of dc and ac susceptibility measurements point to an AF exchange coupling between nearest neighboring Ni(ll) ions. Below 5 K, the compound orders magnetically showing the typical features of a canted antiferromagnet. The magnetic behavior and magnetic dimensionality of Ni[(C6H5PO3)(H2O)] have been fully analyzed and compared to those of the Ni(II) parent compounds Ni[(RPO3)(H2O)] (where R = CH3, C18H37), which exhibit different symmetries of the inorganic layers and lengths of the R groups. [ABSTRACT FROM AUTHOR]

Cr[(H[sub 3]N-(CH[sub 2])[sub 2]-PO[sub 3])(Cl)(H[sub 2]O)], a rare example of a polar organic-inorganic hybrid material containing Cr[sup 2+], was prepared from CrCl[sub 2], 2-aminoethylphosphonic acid, and urea in water and isolated as light-blue crystals. It crystallizes in the noncentrosymmetric monoclinic space group P2[sub 1], with a = 5.249(1) Å, b = 14.133(3) Å, c = 5.275(1) Å, and β = 105.55(2)°. The inorganic layer of the hybrid network is formed by C r(II) five-coordinated by three oxygen atoms from the phosphonates and one from the water molecule in a square pyramidal unit, whose apical position is occupied by the Cl[sup -] ion. Hydrogen bonds are established between the coordinating water molecule and the oxygen atoms of adjacent phosphonate ligands. The inorganic network is interspersed by ethylammonium groups, and the terminal ammonium moiety is linked to the apical Cl[sup -] ions through hydrogen bonds. Electrostatic interactions as well as hydrogen bonds and the coordinated chlorine atoms ensure the cohesion of the 3D structure. The lattice is polar (lack of inversion center), and this fact determines the magnetic behavior of the compound at low temperatures. The magnetic susceptibility data in the temperature range from 300 to 50 K show Curie-Weiss behavior, with C = 2.716 cm³ K mol[sup -1] and the Weiss constant θ = -2.2 K. The corresponding effective magnetic moment of 4.7 µ[sub B] compares well with the expected value for Cr[sup 2+] in d[sup 4] high-spin configuration. A slight decrease of the χ[sup T] product versus T observed at temperatures below 50 K indicates nearest-neighbor antiferromagnetic exchange interactions. On cooling below T = 6 K, the magnetic susceptibility increases sharply up to a maximum at ca. 5 K and then decreases again. Below T = 6 K, hysteresis loops taken at different temperatures show that Cr[(H[sub 3]N-(CH[sub 2])[sub 2]-PO[sub 3])(Cl)(H[sub 2]O)] behaves as a weak ferromagnet with the critical temperature T[sub N] at 5.5 K. The spin canting is responsible of the long-range magnetic ordering. The values of the coercive field, H[sub c], and of remnant magnetization, M[sub r], obtained from the hysteresis loop at T = 4.5 K (the lowest measured temperature) are 30 Oe and 0.08 µ[sub B], respectively. [ABSTRACT FROM AUTHOR]

Examines the compound (perylene)3[Bi4Br12), which is an arene ...-complex containing the [Bi4Br10] unit. How the compound was obtained; Observations of EPR signals; Electronic absorption spectrum of the compound.