Reactivity of the unsaturated dimolybdenum anion [Mo2(η-C5H5)2(μ-PCy2)(μ-CO)2] towards electrophiles based on p- and d-block elements

The 30-electron binuclear anion [Mo₂Cp₂(μ-PCy₂)(μ-CO)₂]⁻ reacts with the chlorophosphite ClP(OEt)₂ or the organotin chlorides Cl₂SnPh₂ or ClSnPh₃ to give compounds of the formula trans-[Mo₂Cp₂(μ-E)(μ-PCy₂)(CO)₂], (E = P(OEt)₂, SnPh₃, SnPh₂Cl). In contrast, this anion reacts with the organosilicon chlorides ClSiR₃ (R = Ph, Me) to give unstable silyloxycarbyne-bridged complexes [Mo₂Cp₂(μ-PCy₂)(μ-COSiR₃)(μ-CO)], which rapidly hydrolyze to give the known hydride [Mo₂Cp₂(μ-H)(μ-PCy₂)(CO)₂]. Two main types of products were also observed in the reactions of the title anion with different chlorocomplexes of the transition and post-transition metals. Thus, the reactions with [MCl₂Cp₂] (M = Ti, Zr) give moisture-sensitive isocarbonyl-bridged complexes of the type [Mo₂Cp₂(μ-COMClCp₂)(μ-PCy₂)(μ-CO)]. In contrast, softer metallic electrophiles such as [AuCl(PR₃)] (R = ⁱPr, ptol) react with the anion at the dimolybdenum site to form new trimetallic clusters of the formula [AuMo₂Cp₂(μ-PCy₂)(CO)₂(PR₃)], also retaining a Mo−Mo triple bond. Subsequent reactions of the latter products with the solvate complexes [Au(PR₃)(THF)][PF₆] give the tetranuclear clusters [Au₂Mo₂Cp₂(μ-PCy₂)(CO)₂(PR₃)₂][PF₆] (Mo−Mo = 2.5674(3) Å and Au−Au = 2.7832(2) Å when R = ⁱPr). Finally, the reaction of the title anion with HgI₂ gives the pentanuclear cluster [Hg{Mo₂Cp₂(μ-PCy₂)(CO)₂}₂] or the trinuclear cluster [Mo₂Cp₂(μ-HgI)(μ-PCy₂)(CO)₂] depending on the stoichiometry being actually used for the reaction. The trinuclear species is only stable in tetrahydrofuran (THF), and decomposes to give a mixture of the dimeric species [Mo₂Cp₂(μ-HgI)(μ-PCy₂)(CO)₂]₂ along with variable amounts of the known iodide-bridged complex [Mo₂Cp₂(μ-I)(μ-PCy₂)(CO)₂].     

Heterometallic M/Mn (M=Cu, Co, Zn) acetate complexes as precursors for binary oxides

A facile one-pot procedure, or so-called “direct synthesis,” was used to prepare the novel heterometallic complexes [M₂Mn(OAc)₆(bpy)₂], where M=Cu (1), Co (2), Zn (3), bpy=2,2′-bipyridyl, with high yields via oxidative dissolution of pure metals in a liquid phase. The complexes were characterized by an elemental analysis, single crystal X-ray diffraction method and FTIR. These complexes are proposed as precursors, whose thermal degradation may lead to the formation of solids possessing nano- to microsize levels of dispersity. The thermal behavior of the complexes obtained was studied by thermal analysis (TG/DTA/DTG) in both air and N₂ and also by TPD mass-spectrometry in vacuo. The FTIR, X-ray powder diffraction (PXRD) and thermoanalytical data were used for the identification of the solid products of thermal degradation. The morphology and microstructure of the solid residues were analyzed, using scanning electron microscopy with energy dispersive X-ray microanalysis (SEM/EDX) at mkm and sub-micro levels.     

Synthesis, structure, solid-state thermolysis, and thermodynamic properties of new heterometallic complex Li2Co2(Piv)6(NEt3)2

The reaction of lithium pivalate, polymeric cobalt pivalate [Co(Piv)₂]_n, and triethylamine in THF at 60 °С afforded the new heterometallic antiferromagnetic complex Li₂Co₂(Piv)₆(NEt₃)₂ (2). The molecular and crystal structure of complex 2 was established and its magnetic behavior was studied. The vaporization and solid-state thermolysis of 2 were investigated. The thermodynamic characteristics of complex 2 were determined. The results of the present study show that complex 2 can be used as a potential molecular precursor for the synthesis of thin films of lithium cobaltate LiCoO₂.     

Construction of optically active multimetallic systems of rhodium(I), palladium(II), and ruthenium(II) with a P-chiral tetraphosphine ligand

The treatment of optically P-chiral tetraphosphine, (3S,6R,9R,12S)-6,9-di-tert-butyl-2,2,3,12,13,13-hexamethyl-3,6,9,12-tetraphosphatetradecane (1), with rhodium(I), palladium(II), and ruthenium(II) complex precursors led to the selective formation of mono-, di-, or trinuclear homo- or heterometallic complexes, [Rh(1)]SbF₆ (4), [{Rh(nbd)}₂(1)](SbF₆)₂ (3), [{Pd(η³-allyl)}₂(1)](SbF₆)₂ (5), [{RuCl(η⁵-C₅(CH₃)₅)}₂(1)] (6), and [{RuCl₂(η⁶-benzene)}₂(PdCl₂)(1)] (8). These complexes were characterized by NMR and X-ray crystallographic analysis.     

Coordination polymer [Li2Co2(Piv)6(μ-L)2]n (L = 2-amino-5-methylpyridine) as a new molecular precursor for LiCoO2 cathode material

The solid-state thermolysis (420–450 °С) of the new heterometallic coordination polymer [Li₂Co₂(Piv)₆(μ-L)₂]_n (1, Piv is the anion of pivalic acid, L is 2-amino-5-methylpyridine) followed by annealing of the decomposition products at 500 °С was shown to afford LiCoO₂ in quantitative yield. Compound 1 was characterized by X-ray diffraction and magnetic measurements.     

Three Dicyanidometallate(I)‐based Complexes Incorporating Hydrogen‐bonding, π–π Packing and d10–d10 Interactions with Auxiliary 2,2′‐Bipyridyl‐like Ligands

To investigate the influence of the non‐covalent interactions, such as hydrogen‐bonding, π–π packing and d¹⁰–d¹⁰ interactions in the supramolecular motifs, three cyanido‐bridged heterobimetallic discrete complexes {Mn(bipy)₂(H₂O)[Ag(CN)₂]}[Ag(CN)₂] ( 1 ), {Mn(phen)₂(H₂O)[Au(CN)₂]}₂[Au(CN)₂]₂ · 4H₂O ( 2 ), and {Cd(bipy)₂(H₂O)[Au(CN)₂]}[Au(CN)₂] ( 3 ) (bipy = 2,2′‐bipyridine, and phen = 1,10‐phenanthroline), which are based on dicyanidometallate(I) groups with 1:2 stoichiometry of metal ions and 2,2′‐bipyridyl‐like co‐ligands were synthesized and structurally characterized. In compound 1 , hydrogen bonding and π–π interactions governed the supramolecular contacts. In compound 2 , the incorporation of aurophilic, hydrogen bonding and π–π interactions result in a 3D supramolecular network. In compound 3 , hydrogen bonding and π–π stacking interactions result in a 2D supramolecular layer. In the three complexes, hydrogen‐bonding, π–π packing and/or d¹⁰–d¹⁰ interactions can play important roles in increasing the dimensionality of supramolecular assemblies.     

Synthesis and crystal structure of a three-dimensional 3d-4f heterometallic supramolecular complex {Eu(DMF)4(H2O)2Cr(CN)6·;H2O} n

A lanthanide-transition heterometallic supramolecular complex {Eu(DMF)₄(H₂O)₂Cr(CN)₆·H₂O} _n (1) has been synthesized based on the reaction of K₃[Cr(CN)₆], N,N-dimethylformamide (DMF) and Eu(NO₃)₃·6H₂O. 1 crystallizes in the monoclinic space group P2(1)/c with a=13.130(6)Å, b=12.923(7)Å, c=19.184(9)Å and Z=4. In 1 each Eu(III) is eight-coordinate with six oxygen atoms from four DMF molecules and two H₂O molecules and two nitrogen atoms from two cis-bridging CN ligands to form a distorted dodecahedron. 1 has a three-dimensional network created by the incorporation of coordinative linkage, three inter-molecular and an intrachain hydrogen bond.     

Edta-linked 5p–4f trinuclear heterometallic complex: syntheses,X-ray structure and luminescent properties

A new heterometallic antimony–samarium complex, [Sb₂(edta)₂Sm(H₂O)₄]NO_3?·?3.55H₂O (edta?=?ethylenediaminetetraacetate) (1), has been synthesized and characterized by elemental analyses (EA), Fourier transform infrared spectroscopy, thermogravimetry-differential scanning calorimetry, and X-ray crystallography. The X-ray crystal structure analysis reveals that in 1 the bridging carboxylate-O,O′ of edta^4? connects samarium(III) and antimony(III) to form 2-D sheets. The 2-D sheets are further linked by bridging carboxylates from adjacent layers, resulting in 3-D coordination polymers. Complex 1 exhibits fluorescence in the solid state at room temperature.     

Synthesis,structure, DNA-binding,and nuclease activity of a 3d–4f mixed metal nitrosyl complex, [Pr(phen)2(MeOH)(H2O)2][Fe(CN)5(NO)] · (Phen)(DMF)(MeOH)(H2O)

A cyano-bridged heterometallic lanthanide-transition metal nitrosyl complex, [Pr(phen)₂(MeOH)(H₂O)₂][Fe(CN)₅(NO)]?·?(Phen)(DMF)(MeOH)(H₂O) (Phen?=?1,10-phenanthroline and DMF?=?dimethylformamide), has been synthesized from reaction of PrCl₃?·?6H₂O with 1,10-phenanthroline in methanol and sodium nitroprusside followed by crystallization from DMF. The crystal structure shows that the complex is a 1-D chain, stabilized by coordination, hydrogen-bonding, and π–π stacking interactions. The complex shows nuclease activity with pUC19 supercoiled DNA in DMF/Tris-HCl buffer in the presence of H₂O₂.     

Syntheses,structures and magnetic properties of isonicotinate-bridged heterometallic Ln(III)–Cu(II) coordination polymers

The heterometallic Ln(III)–Cu(II) coordination polymers [CuLn₂(IN)₈(H₂O)₄] _n (IN?=?isonicotinate, Ln?=?Gd (1), Dy (2), Er(3)) have been synthesized by hydrothermal reactions and characterized by elemental analysis, IR and single crystal X-ray diffraction. The compounds are isomorphous and crystallize in monoclinic space group P2₁/c, adopting a one-dimensional chain structure with alternately arranged [Ln₂(IN)₆(H₂O)₄] and [Cu(IN)₂] building blocks bridged by isonicotinates. Temperature-dependent magnetic susceptibility for complex 1 was studied, and a very weak ferromagnetic interaction between metal ions was observed.