New fulvalenium salts of bis(dicarbollide) cobalt and iron: Synthesis, crystal structure and electrical conductivity

New radical cation salts (BEDT-TTF)₂[3,3′-Co(1,2-C₂B₉H₁₁)₂] (1), (BEDT-TTF)₂[8-I-3,3′-Co(1,2-C₂B₉H₁₀)(1′,2′-C₂B₉H₁₁)] (2), (BMDT-TTF)[3,3′-Co(1,2-C₂B₉H₁₁)₂] (3) and (TMTSF)₂[3,3′-Fe(1,2-C₂B₉H₁₁)₂] (4) were synthesized and their crystal structures and electrical conductivities were determined. Compound 4 is isostructural to the earlier reported Co analogue. All the radical cation salts synthesized are semiconductors.     

Molecular conductors with 8,8′-diiodo cobalt bis(dicarbollide) anion

New molecular conductors on the base of 8,8′-diiodo cobalt bis(dicarbollide) anion (TTF)[8,8′-I₂-3,3′-Co(1,2-C₂B₉H₁₀)₂] (1), (BMDT-TTF)₄[8,8′-I₂-3,3′-Co(1,2-C₂B₉H₁₀)₂] (2) and (BEDT-TTF)₂[8,8′-I₂-3,3′-Co(1,2-C₂B₉H₁₀)₂] (3) were synthesized and their crystal structures and electrical conductivities were determined. All the radical cation salts prepared were found to be semiconductors. Some regularities in the crystal structures of the TTF-based radical cation salts with bis(dicarbollide) complexes of transition metals are discussed.     

Synthesis and characterization of sodium bis(trimethylstannyl) amide and bis(trimethylsilyl) bis(trimethylstannyl) -phospha-tetrazene

Sodium bis(trimethylstannyl)amide NaN(SnMe₃)₂, isolated by the reaction of trimethylstannyldiethylamine with sodium amide, reacts with tris(trimethylsilyl)hydrazino—dichloro-phosphine to form bis(trimethylsilyl)bis(trimethylstannyl)-2-phospha-2-tetrazene, (Me₃Si)₂N-N=P-N(SnMe₃)₂. Both the molecules have been isolated and characterized.     

Synthesis, crystal structure and magnetic behavior of two cobalt coordination polymers with 1,2-bis(1,2,4-triazol-1-yl)ethane and dicyanamide

Two cobalt(II) coordination polymers formed from bte (bte = 1,2-bis(1,2,4-triazol-1-yl)ethane), namely [Co(bte)₂(dca)₂]_n (1) and {[Co(bte)(dca)₂] · H₂O}_n (2), have been synthesized and characterized by elementary analyses, IR, thermogravimetric analyses, X-ray diffraction analyses and magnetic measurements. Compound 1 is a double-chain with Co(II) centers bridged by bte, containing metallocycles of [Co₂(bte)₂] and trans dca as termination ligands. In 2, each Co(II) center is bonded by two bridging bte ligands and four dca as μ-1,5-dca in different orientations in the 3D network.     

Constructions of a set of novel hydrogen-bonded supramolecules from reactions of cobalt(II) salt with bis(3,5-dimethylpyrazolyl)methane and different carboxylic acids

Reactions of CoX₂·6H₂O (X = Cl⁻, ClO₄⁻) with bis(3,5-dimethylpyrazolyl)methane (dmpzm) and formic acid, acetic acid, benzoic acid, salicylic acid, maleic acid, or fumaric acid under the presence of KOH solution produced a new family of Co(II)/dmpzm complexes, [Co(dmpzm)₂L]X·nH₂O (1: L = O₂CH, X = Cl, n = 2; 2: L = OAc, X = Cl, n = 3; 3: L = benzoate, X = ClO₄, n = 1/3; 4: L = salicylate, X = ClO₄, n = 1/3) and [Co₂(dmpzm)₄L](ClO₄)₂·nSolv (5: L = maleate, n = 3, Solv = H₂O; 6: L = fumarate, n = 2, Solv = MeOH). These compounds were structurally characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Compounds 1–4 are mononuclear while 5–6 are binuclear. Each cobalt atom of 1–6 is hexacoordinate, with a distorted octahedral CoN₄O₂ coordination geometry incorporating two N,N′-bidentate dmpzm ligands and one O,O′-bidentate carboxylate ligand. There are rich intra- and intermolecular hydrogen bonds in the crystals of 1–6, thereby forming either 2D hydrogen-bonded networks (1 and 2) or 3D hydrogen-bonded networks (3–6). In addition, the thermal behaviors of 1–6 were also investigated.     

Synthesis,characterization, electrochemical and crystal structure investigation of bis(2-((2-aminoethylimino)methyl)-6-methoxyphenolato) cobalt(III)

The mononuclear cobalt(III) complex [Co(L)₂]Cl ·?H₂O (1) (where L is H₂N(CH₂)₂N=CC₆H₃(OMe)(O^?)) has been prepared and characterized by IR, UV-Vis spectroscopy, conductivity measurements, elemental analysis, TGA, cyclic voltammetry and an X-ray structure determination. The cobalt(III) coordination sphere in [Co(L)2] is cis-CoN₄O₂ with the NNO ligands. Electrochemical studies of 1 using cyclic voltammetry indicate an irreversible cathodic peak (E _pc, ca ?0.60 V) corresponding to reduction of cobalt(III) to cobalt(II).     

Synthesis,crystal structure,and fluorescence of an unexpected dialkoxo-bridged dinuclear copper(II) complex with bis(salen)-type tetraoxime

An unexpected dinuclear Cu(II) complex, [Cu₂(L²)₂] (H₂L^2?=?3-methoxysalicylaldehyde O-(2-hydroxyethyl)oxime), has been synthesized via complexation of Cu(II) acetate monohydrate with H₄L¹. Catalysis by Cu(II) results in unexpected cleavage of two N–O bonds in H₄L¹, giving a dialkoxo-bridged dinuclear Cu(II) complex possessing a Cu–O–Cu–O four-membered ring core instead of the usual bis(salen)-type tetraoxime Cu₃–N₄O₄ complex. Every complex links six other molecules into an infinite-layered supramolecular structure via 12 intermolecular C–H?···?O hydrogen bonds. Furthermore, Cu(II) complex exhibits purple emission with maximum emission wavelength λ_max?=?417?nm when excited with 312?nm.     

Synthesis,crystal structure and catalytic performance of bis (imino)pyridyl nickel complexes

Two new Ni(II) complexes of 2,6-bis[1-(2,6-diethylphenylimino)ethyl]pyridine (L¹), 2,6-bis[1-(4-methylphenylimino)ethyl]pyridine (L² ) have been synthesized and structurally characterized. Complex Ni(L¹)Cl₂?·?CH₃CN (1), exhibits a distorted trigonal bipyramidal geometry, whereas complex Ni(L¹)(CH₃CN)Cl₂ (2), is six-coordinate with a geometry that can best be described as distorted octahedral. The catalytic activities of complexes 1, 2, Ni{2,6-bis[1-(2,6-diisopropyl-phenylimino)ethyl]pyridine} Cl₂?·?CH₃CN (3), and Ni{2,6-bis[1-(2,6-dimethylphenylimino) ethyl]pyridine}Cl₂?·?CH₃CN (4), for ethylene polymerization were studied under activation with MAO.     

Synthesis,crystal structure,and antibacterial activity of mononuclear nickel(II) and cobalt(III) Schiff-base complexes

Four new mononuclear complexes, [Ni(L¹)(NCS)₂] (1), [Ni(L²)(NCS)₂] (2), [Co(L¹)(N₃)₂]ClO₄ (3), and [Co(L²)(N₃)₂]ClO₄ (4), where L¹ and L² are N,N′-bis[(pyridin-2-yl)methylidene]butane-1,4-diamine and N,N′-bis[(pyridin-2-yl)benzylidene]butane-1,4-diamine, respectively, have been prepared. The syntheses have been achieved by reaction of the respective metal perchlorate with the tetradentate Schiff bases, L¹ and L², in presence of thiocyanate (for 1 and 2) or azide (for 3 and 4). The complexes have been characterized by microanalytical, spectroscopic, single crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1–4 are distorted octahedral geometries. The antibacterial activity of all the complexes and their constituent Schiff bases have been tested against Gram-positive and Gram-negative bacteria.     

Synthesis,crystal structure and magnetism of 1D cobalt(II) coordination polymer with thiocyanate as bridging ligand

A one-dimensional coordination polymer [Co(μ _1,3-NCS)₂(npdo)₂] _n (npdo?=?4-nitropyridine N-oxide) has been synthesized and structurally determined by X-ray crystallography. The complex crystallizes in the orthorhombic space group of Pbcn with a?=?22.688(5)?Å, b?=?7.2636(17)?Å, c?=?10.299(2)?Å. Adjacent Co(II) ions are coordinated by two μ _1,3-SCN^? bridging ligands, forming a one-dimensional chain along the c axis and the npdo coordinates to Co(II) ion as a terminal ligand. The thermal variation of the magnetic moments of the complex reflects the antiferromagnetic interaction between the bridged Co(II) ions above 20?K and the ferromagnetic transition or the strong short-range spin interaction below 20?K.     

Synthesis,characterization, and crystal structure of three cobalt(II) complexes with Schiff bases derived from rimantadine

By condensation of rimantadine and substituted salicylaldehyde, three new Schiff bases, HL¹, HL² and HL³, were synthesized. Then, a mixture of one of the new ligands and cobalt(II) chloride hexahydrate in ethanol led to 1, 2, and 3, respectively. These complexes were characterized by melting point, elemental analysis, infrared spectra, molar conductance, thermal analysis, and single-crystal X-ray diffraction analysis. X-ray diffraction analysis reveals that 1 crystallizes in the orthorhombic system, Pbcn space group; each asymmetric unit consists of one cobalt(II) ion, two deprotonated ligands, and one lattice water. The central cobalt is four coordinate via two nitrogens and two oxygens from the corresponding Schiff base ligand, forming a distorted tetrahedral geometry. Complexes 2 and 3 crystallize in the monoclinic system, P2₁/c space group; each asymmetric unit consists of one cobalt(II), two corresponding deprotonated ligands, one lattice water, and one methanol. The central cobalt is also four-coordinate via two nitrogens and two oxygens from the corresponding Schiff base ligand, forming a distorted tetrahedral geometry.     

Bridged bis(amidinate) lanthanide complexes: Synthesis,molecular structure and reactivity

The yttrium chloride with the bridged bis(amidinate) L (L = Me₃SiNC(Ph)N(CH₂)₃NC(Ph)NSiMe₃) LYCl(DME) (2) was synthesized and structurally characterized. Treatment of LLnCl(sol)_x (Ln = Yb, sol = THF, x = 2 1; Ln = Y, sol = DME, x = 1 2) with the dilithium salt Li₂L(THF)_0.5 afforded the novel bimetallic lanthanide complexes supported by three ligands, Ln₂(μ₂-L)₃ · DME (Ln = Yb 3, Y 4; DME = dimethylether), instead of the designed complex LLn(μ₂-L)LnL via the ligand redistribution reaction. Complexes 3 and 4 were fully characterized including X-ray analysis and ¹H NMR spectrum for 4. Reaction of LnCl₃ (Ln = Yb, Y) with 2 equiv. of Li₂L(THF)_0.5 gave the anionic complexes [Li(DME)₃][L₂Ln] (Ln = Yb 5, Y 6), which were confirmed by a crystal structure determination. The further study indicated that complexes 3 and 4 can also be synthesized by reaction of LnCl₃ (Ln = Yb, Y) with 1.5 equiv. of Li₂L(THF)_0.5 or reaction of 1 and 2 with anionic complexes 5 and 6. Complexes 3, 4, 5 and 6 were found to be high active catalysts for ring-opening polymerization of ε-caprolactone (CL).     

Synthesis,structure, and properties of a pentanuclear cobalt(III) coordination cluster

The synthesis, X-ray structure and properties of a pentanuclear cobalt(III) coordination cluster [{L(O₂CCH₃)Co₂O(OCH₃)₂}₂Co](ClO₄)₃ (1) (L^? = 2,6-bis((3-aminopropylimino)methyl)-4-methylphenolate) are described. The dinucleating L^? is coordinated with two cobalt(III) centers to form the {L(O₂CCH₃)Co₂O(OCH₃)₂} unit, where each metal center is in a distorted octahedral N₂O₄ environment. The oxo and the methoxo ligands of these two dinuclear units assemble a distorted octahedral O₆ coordination sphere around the central cobalt(III). Elemental analysis and spectroscopic (IR, NMR, UV–vis, and HRMS) features are consistent with the pentanuclear structure of the complex. The diamagnetic complex is a 1?:?3 electrolyte in solution. It is redox-active and displays a metal-centered reduction at E_1/2 = ?0.04 V (vs. Ag/AgCl).     

Synthesis,crystal structure,electronic structure and electrical conductivity of La3GeSb0.31Se7 and La3SnFe0.61Se7

The selenides La₃EM_1−xSe₇ (La₆E₂M_2−xSe₁₄) adopt the Ce₆Al_3.33S₁₄ structure type. La₃GeSb_0.31Se₇ and La₃SnFe_0.61Se₇ crystallize in the non-centrosymmetric space group P6₃ with La replacing Ce in the 6c site, E = Ge or Sn replacing Al in the 2b site and M = Fe or Sb replacing the other, deficient Al site (2a). The structure contains La atoms in square antiprisms of Se atoms, isolated distorted [ESe₄] tetrahedra, and face sharing distorted [MSe₆] octahedra forming a linear chain along the c-axis with short M–M distances. Band structure calculations predict semiconducting character with different gaps, which was demonstrated by electrical conductivity measurements and reflected in their different colors.     

Synthesis of functional derivatives of the [3,3′-Co(1,2-C2B9H11)2] anion

A series of various functional derivatives of the cobalt bis(1,2-dicarbollide) anion [8-XCH₂CH₂OCH₂CH₂O-3,3′-Co(1,2-C₂B₉H₁₀)(1′,2′-C₂B₉H₁₁)]⁻ (X=OH, NH₂, and CH(NH₂)COOH) were prepared by the ring-opening reactions of [8-O(CH₂CH₂)₂O-3,3′-Co(1,2-C₂B₉H₁₀)(1′,2′-C₂B₉H₁₁)] with different nucleophiles followed by functional group interconversion reactions. Acidic hydrolysis of [8-NCCH₂CH₂OCH₂CH₂O-3,3′-Co(1,2-C₂B₉H₁₀)(1′,2′-C₂B₉H₁₁)]⁻ resulted in the shorter-chain alcohol [8-HOCH₂CH₂O-3,3′-Co(1,2-C₂B₉H₁₀)(1′,2′-C₂B₉H₁₁)]⁻. Structures of (Bu₄N)[8-AcNHC(COOEt)₂CH₂CH₂OCH₂CH₂O-3,3′-Co(1,2-C₂B₉H₁₀)(1′,2′-C₂B₉H₁₁)] and [8-(1-C₅H₅N)CH₂CH₂OCH₂CH₂O-3,3′-Co(1,2-C₂B₉H₁₀)(1′,2′-C₂B₉H₁₁)] were determined by the single crystal X-ray diffraction method. Perspectives of application of functionalized cobalt bis(1,2-dicarbolide) derivatives in nuclear medicine are discussed.     

Synthesis and crystal structures of bis(cyclopentyl)gallium phenoxide dimer and bis (cyclopentyl) gallium naphthoxide dimer

Tricyclopentylgallium reacted with phenol, naphthol respectively to yield phenox-ide (or naphthoxide) of biscyclopentylgallium which have been characterized by elemental analysis, IR, 1H NMR and mass spectrometry. X-ray diffraction analysis of compound 1 indicated that it belongs to the monoclinic system, space groups P21/c, with cell constants 0=9.602(3), 6=14.365(7), c=11.256(4)A, and β=97.54(3)°, Z=2(dimers), R=0.0706. Compound 2 assigned to the triclinic system, space groups P1 with cell constants a=9.392(4), 6=9.928(7), c=11.263(7) A, a=112.48(5), β=104.74(4), γ=99.95(5)°, and Z=l(dimers), R=0.0526. The molecule of 1 or 2 contains an oxygen-bridged coplanar Ga2O2 four-membered ring respectively.     

Bis(dicarbollide) Complexes of Transition Metals as a Platform for Molecular Switches. Study of Complexation of 8,8′-Bis(methylsulfanyl) Derivatives of Cobalt and Iron Bis(dicarbollides)

Complexation of the 8,8′-bis(methylsulfanyl) derivatives of cobalt and iron bis(dicarbollides) [8,8′-(MeS)₂-3,3′-M(1,2-C₂B₉H₁₀)₂]⁻ (M = Co, Fe) with copper, silver, palladium and rhodium leads to the formation of the corresponding chelate complexes, which is accompanied by a transition from the transoid to the cisoid conformation of the bis(dicarbollide) complex. This transition is reversible and can be used in design of coordination-driven molecular switches based on transition metal bis(dicarbollide) complexes. The solid-state structures of {(Ph₃P)ClPd[8,8′- (MeS)₂-3,3′-Co(1,2-C₂B₉H₁₀)₂-κ²-S,S′]} and {(COD)Rh[8,8′-(MeS)₂-3,3′-Co(1,2-C₂B₉H₁₀)₂-κ²-S,S′]} were determined by single crystal X-ray diffraction.     

Syntheses and structural characterization of six ionic salts based on bis(benzimidazole)/bis(imidazole) and perchlorometallates of Zn and Cu

Six salts, ([(H₂L1)(ZnCl₄)] (1) (L1 = 1,1′-bis(benzimidazolyl)methane), [(H₂L1)(CuCl₄)]·H₂O (2), [(H₂L2)(ZnCl₄)] (3) (L2 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole), [( H₂L2)(CuCl₄)] (4), [(H₂L3)(CuCl₄)]·H₂O (5) (L3 = 1- (4-(1H-benzimidazol-1-yl)butyl)-1H-benzimidazole), and [(H₂L4)(ZnCl₄)]·H₂O (6) (L4 = 3,6-bis(imidazol-1-yl)pyridazine)), derived from bis(benzimidazole)/bis(imidazole) and metal(II) chloride dihydrate (zinc(II) chloride and copper(II) chloride dihydrate) were prepared and characterized by IR, X-ray structure analysis, elemental analysis, and TG analysis. The aromatic rings of the cations in all of the compounds are planar. X-ray diffraction analysis revealed that all the complexes have 3-D layer network structures built from hydrogen bonds between the cations and chlorometallate anions. Water molecules also play an important role in structure extension in 2, 5, and 6. The arrangements of the anions and cations in their solid state are dominated not only by size and symmetry of the cations, but also by the non-covalent interactions existing in the crystal structures.     

Crystal structure of the organic metal (ET)2[Hg(SCN)2Cl] withT M-D=50 K

The composition and structure of the radical-ion salt (ET) ₂ [Hg(SCN) ₂ Cl], a new organic metal withT _M-D=50 K, were established in an x-ray structure investigation. Principal crystallographic data:a=36.69(1),b=8.302(8),c=11.732(8) Å, =90.02(6)°, space groupCc, Z=4,d _calc=2.08 g/cm ³ ,R=0.067. The crystal structure of the salt consists of an alternation of organic (cationic) and inorganic (anionic) layers along the axisa. The anionic layer consists of the polymeric chains in which the [Hg(SCN) ₂ Cl]^– ions are linked together along the axisc through secondary Hg···N bonds with lengths of 2.75(3) and 2.98(8) Å. On account of these interactions the trigonal configuration of the bonds of the Hg atom is built up to trigonal-bipyramidal. In the organic layer with a structure of the type the ET cations form dimers with an interplanar distance of 3.53 Å. ET cations belonging to neighboring dimers are linked together through shortened intermolecular S...S contacts with lengths of 3.40–3.50(2) Å.Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka 142432. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 903–909, April, 1992.