Synthesis, Crystal Structures, Electronic Spectra, and Magnetic Properties of Thiolato-Bridged Trinuclear Cobalt(II) Complexes with N, N, S-Tridentate Thiolate Ligands

New trinuclear CoII complexes, [{Co(apaet)2}2Co]X2 (apaet– = 2-[(3-aminopropyl)amino]ethanethiolato; X = SCN (1), ClO4 (2), NO3 (3), Cl (4), Br (5), I (6)) and [{Co(apampt)2}2Co]X2 (apampt– = 1-[(3-aminopropyl)amino]-2-methylpropane-2-thiolato; X = NO3(7), ClO4 (8), Cl (9), Br (10), I (11)), and mononuclear CoIII complexes, [Co(apaet)2]X (X = ClO4 (12), NO3 (13)), were synthesized. Single-crystal X-ray crystallography of 1 and 7 confirmed that the trinuclear complexes have a linear arrangement of octahedral CoIIS2N4-tetrahedral CoIIS4-octahedral CoIIS2N4 chromophores where two thiolate ligands are coordinated to each terminal Co atom in a mer coordination mode and the two thiolato S atoms are further bound to the central Co atom, which is consistent with the electronic spectra and antiferromagnetic propertie

Tetra(n-butyl)ammonium salt of a ferrimagnetic complex based on mixed-valent dinuclear ruthenium pivalate and octacyanidotungstate(V)

International audienceA tetra (n-butyl)ammonium (n-Bu4N+) salt of Ru2–W complex consisting of dinuclear ruthenium (II,III) pivalate, ([RuIIRuIII(piv)4]+) (Hpiv = pivalic acid), and octacyanidotungstate(V), [n-Bu4N][{RuIIRuIII(piv)4}2(H2O){WV(CN)8}] (1), was synthesized and characterized by elemental analysis, infrared spectra, and temperature dependence of magnetic susceptibilities (2–300 K). The crystal structure of 1 revealed a zigzag one-dimensional chain molecule along the c axis with alternating arrangement of [RuIIRuIII(piv)4]+ and [WV(CN)8]3−, where another [RuIIRuIII(piv)4]+ unit is dangled from the [WV(CN)8]3− moiety. The magnetic susceptibilities and zero-field-cooled and field-cooled magnetization data showed that the present complex is ferrimagnetic with a Tc value of 5.5 K. The field dependence of magnetization exhibited a hysteresis with a coercive field of 150 Oe at 2 K

Geometrical Isomerism in Ru2Au Heterometal Assembly: Cis-Linking of Tetracyanidoaurate to Tetrakis(Μ-Butanoato)Diruthenium

A heterometal assembled complex of tetrakis(μ-butanoato)diruthenium(II,III) and tetracyanidoaurate(III) [RuIIRuIII(n-C3H7COO)4AuIII(CN)4]n was synthesized and characterized by the elemental analysis and infrared spectroscopy. The single-crystal X-ray structure analysis revealed that the complex consists of zigzag chain molecules of alternating arrangement of the Ru2(n-C3H7COO)4+ and Au(CN)4– units with cis-bridging mode of the Au(CN)4– units. The temperature dependence of the magnetic susceptibility data (4.5—300 K) showed that the magnetic interaction between the dinuclear RuIIRuIII units (S= 3/2) is negligibly small with a zero-field splitting parameter D value of 60 cm-1

Mixed-Valent Trinuclear CoIII-CoII-CoIII Complex with 1,3-Bis(5-chlorosalicylideneamino)-2-propanol

A mixed-valent trinuclear complex with 1,3-bis(5-chlorosalicylideneamino)-2-propanol (H3clsalpr) was synthesized, and the crystal structure was determined by the single-crystal X-ray diffraction method at 90 K. The molecule is a trinuclear CoIII-CoII-CoIII complex with octahedral geometries, having a tetradentate chelate of the Schiff-base ligand, bridging acetate, monodentate acetate coordination to each terminal Co3+ ion and four bridging phenoxido-oxygen of two Schiff-base ligands, and two bridging acetate-oxygen atoms for the central Co2+ ion. The electronic spectral feature is consistent with the mixed valent CoIII-CoII-CoIII. Variable-temperature magnetic susceptibility data could be analyzed by consideration of the axial distortion of the central Co2+ ion with the parameters Δ = –254 cm−1, λ = –58 cm−1, κ = 0.93, tip = 0.00436 cm3 mol−1, θ = –0.469 K, gz = 6.90, and gx = 2.64, in accordance with a large anisotropy. The cyclic voltammogram showed an irreversible reduction wave at approximately −1.2 V·vs. Fc/Fc+, assignable to the reduction of the terminal Co3+ ions