Structural, Spectral, and Magnetic Properties of End-to-End Di-μ-thiocyanato-Bridged Polymeric Complexes of Ni(II) and Co(II). X-ray Crystal Structure of Di-μ-thiocyanatobis(imidazole)nickel(II)

Abstract

Thiocyanatonickel(II) and thiocyanatocobalt(II) complexes of the composition Ni(NCS)(2)(HIm)(2) (1) and Co(NCS)(2)(HIm)(2) (2), where HIm = imidazole, were prepared and studied. In particular, the crystal structure of Ni(NCS)(2)(HIm)(2) was determined by X-ray methods. This compound crystallizes in the monoclinic system, space group P2(1)/n, with a = 7.720(1) A, b = 5.557(1) A, c = 13.774(3) A, beta = 102.54(3) degrees, and Z = 2. Its structure consists of a one-dimensional polymeric chain in which nickel(II) ions are bridged by two thiocyanate groups bonding in an end-to-end fashion in a trans arrangement. The Ni...Ni distance is 5.557(1) A. The crystal packing is determined by the intermolecular hydrogen bonds and ring-stacking interactions. From their X-ray powder-diffraction patterns and IR spectra, the complexes 1 and 2 were found to be mutually isomorphous. The coordination compounds were identified and characterized using elemental analysis, magnetic measurements, and infrared and ligand-field spectra. Both complexes are first examples of ferromagnetically coupled one-dimensional polymeric compounds with double end-to-end thiocyanate bridges. The magnetic properties of the title compounds were investigated over the 1.9-290 K temperature range. The compounds exhibit long-range magnetic ordering with T(c) equal to 5.0 and 5.5 K for 1 and 2, respectively. Their isothermal magnetization was also studied. The magnetostructural properties of the nickel(II) compound obtained are discussed and compared to those of other double end-to-end thiocyanate-bridged nickel(II) complexes.

A 2D Thiocyanato‐Bridged Copper(II)‐Manganese(II) Bimetallic Coordination Polymer with Ferromagnetic Interactions

“…A certain number of polynuclear complexes have been synthesised with discrete 1-, 2-and 3D crystal structures and some of them exhibit interesting ferromagnetic coupling properties, e.g. the 1D uniform chain complexes [3] Co(NCS) 2 (Hlm) 2 and Ni(NCS) 2 (Hlm) 2 . The heterometallic species, however, are quite limited and show low-dimensional structures, [4Ϫ8] whereas large numbers of cyanato-bridged analogues have been reported and some exhibit interesting magnetic properties.…”

One‐Dimensional CdII Coordination Polymers: Solid Solutions with NiII, Thermal Stabilities and Structures

“…[The nickel() coordination polymer, Ni(NCS) 2 (imidazole) 2 , which contains double thiocyanate bridges has been shown to exhibit long-range magnetic ordering. [39] ]…”

“…[7Ϫ9] Such systems are often tunable by making subtle changes to the reaction conditions, such as the choice of counterion and solution pH, that allow the deliberate design of compounds with luminescent, [10] superconducting [11,12] or magnetic properties [13,14] and also compounds that can be used as nanofibres, [15] in catalysis, [16] in separation processes, [17,18] for gas and liquid storage [19] and in nonlinear optics. [20,21] We have prepared previously one-dimensional coordination polymers of Ni II with aminobenzonitrile isomers and thiocyanate ions as ligands.…”

Architecture of a new selenocyanato bridged one-dimensional polymeric complex of cadmium(II): synthesis, crystal structure and spectroscopic studies

“…In this respect the metal ion, Cd(II) is very well suited for construction of such material as its electronic configuration as well as size permits a wide variety of geometries and coordination numbers [9] Two types of ligands like, neutral organic, e.g., 4,4 0 -bipyridine, pyrazine, etc. [10-12] and anionic, e.g., thiocyanate, azide [8,[13][14][15][16] are generally used to synthesize coordination polymers of different nuclearities. Recently Teo et al has reported the anionic [Cd(XCN) 3 -] ?…”