Trinuclear complexes of 1,3,5,7-tetraketonates. Synthesis, molecular structure, absorption spectra, and electrochemistry of several bis[1,7-diphenyl-1,3,5,7-heptanetetronato(3-)]bis[dioxouranium(VI)]metal(II)-4-pyridine complexes

Synthesis and characterization of homotrimetallic copper complexes derived from bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone

Copper (II) complexes [Cu(3)(nph)(μ(2)-X)(2)(H(2)O)(6)]·2H(2)O [X=Cl (1), (ClO(4)) (3)] and [Cu(3)(nph)(NO(3))(2)(H(2)O)(6)] (2) have been synthesized from bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone in methanol medium and characterized. The structures of the complexes have been discussed in the light of data obtained from analytical, thermoanalytical, mass spectral studies, molar conductance, magnetic moment, electronic, EPR, IR, FT-IR spectroscopic studies. The molar conductance values for the complexes fall in the region 0.5-0.9 Sm(2) mol(-1) in DMSO solution indicating that all of them are non-electrolyte. The magnetic moment values for the complexes suggest weak M-M interaction in the structural unit of the complexes. The dihydrazone ligand is present in enol form in all of the complexes. Copper centre has tetragonally distorted octahedral stereochemistry in chlorido and perchlorato complexes while in nitrato complex, copper has mixed square-pyramidal and distorted-octahedral stereochemistry. The EPR parameters of the complexes indicate that the copper centre has the doublet state as the ground state.

Interaction of neptunium(V) with picolinic, nicotinic and isonicotinic acids

The interaction of Np(V) with all isomers of pyridinemonocarboxylic acid has been investigated, stability constants have been calculated using NIR spectroscopy. Single crystals of [NpO2(Pic)(H2O)2] (1), Cs[NpO2(Pic)2(HPic)]·3H2O (2), [NpO2(Nic)(H2O)] (3), and [NpO2(iso-Nic)(H2O)] (4) have been synthesized. Compound1contains infinite chains; compound2consists of isolated Cs+, [NpO2(Pic)2(HPic)]-groups and water molecules. In both3and4neptunoyl-ion NpO2acts as monodentate ligand with one of the O atoms of NpO2group entering in coordination polyhedron of the adjacent Np atom. Compounds3and4have layered and three-dimensional topologies, respectively. Crystallographic data: [NpO2(Pic)(H2O)2], space groupP¯1, triclinic,a= 6.380(2),b= 7.733(2),c= 10.700(4) Å, α = 96.49(3), β = 106.78(3), γ = 103.83(3)°, andZ= 2 (1); Cs[NpO2(Pic)2(HPic)]·3H2O, space groupP¯1, triclinic,a= 8.707(2),b= 9.777(2),c= 14.640(3) Å, α = 76.633(15), β = 78.75(2), γ = 86.55(2)°, andZ= 2 (2); [NpO2(Nic)(H2O)], space groupP21/n, monoclinic,a= 11.901(4),b= 5.5628(15),c= 12.124(3) Å, β = 101.05(2)°, andZ= 4 (3); [NpO2(iso-Nic)(H2O)], space groupP212121, orthorhombic,a= 5.742(3),b= 8.550(5),c= 18.512(10) Å, andZ= 4 (4). Electron and IR spectra of solid compounds have been measured.

Largest Mixed Transition Metal/Actinide Cluster: A Bimetallic Mn/Th Complex with a [Mn10Th6O22(OH)2]18+ Core

A high-nuclearity mixed transition metal/actinide complex has been prepared from the reaction of a Mn(III)4 complex with Th(NO3)4 in MeCN/MeOH. The complex [Th6Mn10O22(OH)2(O2CPh)16(NO3)2-(H2O)8] is the largest such complex to date and the first Th/Mn species. It is rich in oxide groups, which stabilize all of the metals in the high Th(IV) and Mn(IV) oxidation levels. Magnetic characterization establishes that the complex has an S = 3 ground-state spin value.