The exploration of the NiX(2)/py(2)CO/Et(3)N (X = F, Cl, Br, I; py(2)CO = di-2-pyridyl ketone; Et(3)N = triethylamine) reaction system led to the tetranuclear [Ni(4)Cl(2){py(2)C(OH)O}(2){py(2)C(OMe)O}(2)(MeOH)(2)]Cl(2)·2Et(2)O (1·2Et(2)O) and [Ni(4)Br(2){py(2)C(OH)O}(2){py(2)C(OMe)O}(2)(MeOH)(2)]Br(2)·2Et(2)O (2·2Et(2)O) and the trinuclear [Ni(3){py(2)C(OMe)O}(4)]I(2)·2.5MeOH (3·2.6MeOH), [Ni(3){py(2)C(OMe)O}(4)](NO(3))(0.65)I(1.35)·2MeOH (4·2MeOH) and [Ni(3){py(2)C(OMe)O}(4)](SiF(6))(0.8)F(0.4)·3.5MeOH (5·3.5MeOH) aggregates. The presence of the intermediate size Cl(-) and Br(-) anions resulted in planar tetranuclear complexes with a dense hexagonal packing of cations and donor atoms (tetramolybdate topology) where the X(-) anions participate in the core acting as bridging ligands. The F(-) and I(-) anions do not favour the above arrangement resulting in triangular complexes with an isosceles topology. The magnetic properties of 1-3 have been studied by variable-temperature dc, variable-temperature and variable-field ac magnetic susceptibility techniques and magnetization measurements. All complexes are high-spin with ground states S = 4 for 1 and 2 and S = 3 for 3.
Cage-catenanes are chemical constructs where two or more cage-like molecules or assemblies are mechanically interlocked together. We report a new class of cage-catenanes where dimeric metal-organic cage-catenanes are linked into larger assemblies through additional bridging metal chloride links. These crystalline materials are obtained from the reaction of tris(nicotinoyl)cyclotriguaiacylene (L1) with Cu(II) salts, and all feature a tetramer of cages where two {Cu(L1)(X)} cages (X=anion) are mechanically interlocked, and link to each other and to another {Cu(L1)(X)} cage-catenane through a planar, linear tetranuclear {Cu(μ-Cl)Cl} cluster.
Novel palladium and nickel-sulfur clusters were synthesized using a diamidocarbene-derived carbon disulfide ligand. Structural characterization revealed a tetranuclear metal-sulfur cluster geometry with each metal center exhibiting square-planar coordination. The ligand was redox-active, accommodating oxidation states ranging from 0 to -2.
The electrochemical oxidation of anodic metals (M = nickel and palladium) in an acetonitrile solution of the thiosemicarbazone ligands ()-2-(1-(4-methoxyphenyl)ethylidene)-N-methylhydrazine-1-carbothioamide (a), ()-2-(1-(p-tolyl)ethylidene)hydrazine-1-carbothioamide (b), and ()-N-phenyl-2-(1-(p-tolyl)ethylidene)hydrazine-1-carbothioamide (c) yielded the homoleptic complexes [ML], , , , and and [ML], as air-stable solids. The crystal structures for , , , and show the ligands in a transoid disposition with the [S,S] and [N,N] donor atom pairs occupying positions on the nearly square planar coordination plane of the metal. The structure for of S4 symmetry comprises a tetranuclear palladacycle where the metalated ligands are arranged around a central PdS environment: a crown ring with alternating palladium and sulfur atoms.
A new tetranuclear copper(II) complex [Cu4L2(N3)2(CH3OH)2](NO3)2·4CH3OH (1) and a new trinuclear zinc(II) complex [Zn3L2(CH3COO)2] (2) have been prepared from the bis-Schiff base N,N'-bis(4-bromosalicylidene)-1,3-propanediamine (H2L) with copper nitrate and zinc acetate, respectively, in the presence of sodium azide. The complexes were characterized by elemental analysis, IR and UV-Vis spectroscopy. Molecular structures of both complexes were confirmed by single crystal X-ray determination.
State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
Polynuclear metal hydride clusters play important roles in various catalytic processes, with most of the reported polynuclear metal hydride clusters adopting a polyhedral three-dimensional structure. Herein, we report the first example of a planar tetranuclear uranium hydride cluster [(CpCMeCMeCp)U](μ-H)(μ-H) (UH). It was synthesized by reacting an ansa-bis(cyclopentadienyl) ligand-supported uranium chloride precursor [(CpCMeCMeCp)U](μ-Cl)(μ-Cl) with NaHBEt.
