Crystal structure of [chloro(diethyldithiocarbamato)butyl phenyl]tin(IV)

The crystal structure of the title compound, SnCl(C₆H₅)(C₄H₉)[S₂CN(C₂H₅)₂], was determined and refined to an R factor of 3.2% for 4876 reflections. The molecule contains five-coordinate tin in a distorted trigonal bipyramidal arrangement with the tin atom lying 0.20 Å below the equatorial plane formed by one of the sulphur atoms, S(1), and the donor carbons of the butyl and phenyl groups. The chlorine and the other sulphur atom, S(2), occupy axial sites, making a S(2)SnCl angle of 156.85(1)°. The SnS(2) bond is markedly elongated (2.764(1) Å) compared to the SnCl bond (2.449(1) Å) and the SnS(1) bond (2.454(1) Å). The structure resembles those of analogues such as (C₆H₅)₂Sn(glygly) in having both hydrocarbon ligands located in the equatorial plane. Crystal data: space group P$\text{1}$: a = 8.291(2) Å, b = 14.726(3) Å, c = 9.509(2) Å, α = 96.24(2)°, β = 107.02(3)°, γ = 116.70(2)°, Z = 2, R = 3.2% for 4876 independent reflections.     

Crystal and molecular structure of μ-propane-1,3-diamine Di[bis(propane1,3-diamine) copper(II)]perchlorate complex

The title compound, [Cu₂(1,3-pn)₅](ClO₄)₄, crystallizes in the orthorhombic space group Pbca with Z = 8 formula units in a cell of dimensions: a = 30.88(9), b = 14.664(6), c = 15.737(6) Å. The structure was solved by the heavy-atom method and refined by least-squares calculations to R = 0.082 for 3156 counter data. It consists of discrete dinuclear [Cu₂(1,3-pn)₅]⁴⁺ cations and ClO₄⁻ anions. In the dinuclear cation two propane diamine molecules act as chelating to each copper atom in the basal plane; the fifth amine molecule in an extended form, with its nitrogen atoms located at the apices of two square-pyramides, bridges two copper atoms. Magnetic and spectroscopic data are also discussed.     

Copper(II) halide complexes of 2-aminobenzophenone. Crystal and molecular structure of bis(2-aminobenzophenone)dichlorocopper(II)

The complexes CuX₂L₂ (X = Cl, Br; L = 2-aminobenzophenone) were prepared and characterized by means of magnetic and spectroscopic measurements. For the Cl compound the crystal structure was also determined. Crystals are triclinic, space group P$\text{1}$, with a = 13.397(3), b = 10.752(2), c = 9.205(2) Å, α = 72.26(1)°, β = 91.58(1)°, γ = 106.86(1)°, and Z = 2. The structure was solved by the heavy-atom method and refined by least-squares calculations to R = 0.034 for 2581 counter data. It consists of discrete CuX₂L₂ monomers showing distorted trigonal bipyramidal coordination geometry about the copper ion. The amino nitrogens are axial ligands, with the equatorial positions occupied by two chlorine atoms and a carbonyl oxygen from one L molecule acting as a bidentate ligand. Infrared and ligand field spectroscopies and magnetic measurements, interpreted on the basis of the known crystal structure, also suggest a similar structure for the related Br compound.     

Variability of niobiumsulfur bond lengths: The molecular structures of sulfido-tris(N,N-diethyldithiocarbamato)niobium(V)

In a further examination of the multiply bonded NbS group, the structure of NbS(S₂CNEt₂)₃ has been determined. The compound crystallizes in triclinic space group P$\text{1}$ with a = 9.870(1), b = 15.743(2), c = 16.804(3) Å, α = 101.69(1)°, β = 93.51(1)°, γ = 91.12(1)°, and Z = 4. With use of 6709 unique data (F_O² > 3σ(F_O²)) the structure was refined to R(R_w) = 3.1(3.5%). The crystal contains two inequivalent molecules with distorted pentagonal bipyramidal coordination in which a sulfide atom occupies an axial position. The molecules are differentiated by ethyl group orientations and significantly different NbS bond lengths of 2.122(1) and 2.168(1) Å. Full structural details are reported. The results fall within the ca. 2.09–2.20 Å interval established with other molecules and emphasize the variability in bond length of the NbS group. Stretching frequencies and bond lengths show a rough inverse dependence. For square pyramidal [NbSCl₄]^1?, with a relatively high NbS bond order, v_NbS = 552 cm^?1 is associated with a bond length of 2.085(5) Å and an overlap population of 0.64.     

Polynuclear complexes of copper(II) with the tetra-aza ligand 3,6-bis(2′-pyridyl)pyridazine(L). Crystal structure of the bromine derivative [Cu2L(OH)Br3]n

The tetra-aza ligand 3,6-bis(2′-pyridyl)pyridazine (L), when reacting in appropriate conditions with Cu(II) halides, gives rise to polynuclear complexes of general formula [Cu₂L(OH)X₃]_n (X = Cl or Br). The bromine derivative has been studied by X-ray analysis. The crystals are twins by merohedry of class I, space group Pn (P2₁/n apparent space group), with the following cell constants: a = 13.691(5), b = 6.245(3), c = 10.298(4) Å, β = 103.92(5)°. The structure was refined by least-squares techniques to a final R factor of 0.066. The structure consists of binuclear units joined to each other through bridging bromine atoms to form a polymeric array. The two independent copper atoms of the dinuclear moiety are five-coordinated with a geometry which is intermediate between a square-pyramid and a trigonal-bipyramid.     

Effects of phenoxide ligation: Synthesis and characterization of the [Mo2Fe6S8(SEt)3(OPh)6]3− ion

Reaction of phenol with an alkylthiolate-ligated double cubane complex effects phenolate substitution at the terminal positions; the product can be isolated as its benzyltriethylammonium salt. The phenolate cluster possesses unaltered magnetic properties and blue shifted optical spectra, and undergoes ligand exchange reactions with electrophiles as expected for terminal phenolate substitution. Increased isotropic proton NMR shifts and large negative shifts in corresponding first and second reduction potentials are consistent with increased donation of electron density to the [MoFe₃S₄]³⁺ cores for phenolate versus thiophenolate terminal ligands to iron. Similar behavior has been observed for Fe₄S₄, Fe₂S₂ and MoS₂Fe systems.     

Group IIB metal chloride complexes with some 2-(methylpyridyl or -quinolyl)benz-X-azoles

The complexes formed by Zn(II), Cd(II) and Hg(II) chlorides with benzimidazole, benzoxazole and benzothiazole linked to 4-methylpyridine and 4-methylquinoline have been prepared and characterized by chemical analysis, infrared spectra and conductivity data.The coordination behaviour of these ligands toward the metal salts and the stereochemistry of the obtained complexes have been investigated.     

Metal complexes of the schiff bases 2-pyridinylhydrazine and 2-quinolinyl-hydrazine with 2-pyridinecarboxaldehyde N-oxide,including some N-oxide-bridged antiferromagnetic complexes of cobalt(II) and nickel(II)

Metal complexes of 2-pyridine carboxaldehyde 2′-pyridinylhydrazone 1-oxide (poph) and 2-pyridinecarboxaldehyde 2′-quinolinylhydrazone 1-oxide (poqh) are reported with copper(II), nickel(II), cobalt(II), iron(II) and manganese(II). Each ligand appears to function as an ONN donor, via the pyridine N-oxide oxygen, the imine nitrogen, and a pyridine or quinoline nitrogen. The complexes have been characterised by magnetic susceptibility measurements to liquid nitrogen temperature, and also by electronic, infrared, X-ray powder diffraction, and Mössbauer spectra. No magnetic interaction was detected with the copper(II) complexes. All the complexes of metal nitrates appear to be monomers.The complexes of poph with the halides and thiocyanates of nickel(II) and cobalt(II) appear to be six-coordinate and N-oxide-bridged; they exhibit varying degress of antiferromagnetic interaction and the magnetic data for the nickel(II) complexes have been fitted to various models. In contrast, the bulky ligand poqh produces halide-bridged six-coordinate nickel(II) complexes and monomeric five-coordinate cobalt(II) complexes.This behaviour by poqh resembles that of the related NNN ligands paphy and paqhy, which are the Schiff bases of 2-pyridinecarboxaldehyde with 2-pyridinylhydrazine and 2-quinolinylhydrazine, respectively.     

Electronic spectra of the chromium chalcocarbonyl complexes,Cr(CO)5(CX) and (η6-C6H6)Cr(CO)2(CX) (X= O,S,Se)

The room-temperature electronic spectra of the chromium chalcocarbonyl complexes, Cr(CO)₅(CX) and (η⁶-C₆H₆)Cr(CO)₂(CX) (X = O, S, Se), have been recorded in solution, and in some cases, in the gas phase. Assignments for the thiocarbonyl and selenocarbonyl spectra are proposed on the basis of the literature assignments for the parent all-CO derivatives. Overall, the data support the order of increasing electron withdrawing capacity of the chalcocarbonyl ligands as CO < CS < CSe.     

Metal-phenoxyalkanoic acid interactions. Part 15. The crystal structures of diaquabis(phenoxyacetato)cadmium(II) and catena-μ-[aquabis(phenoxyacetato-O)lead(II)-bis(phenoxyacetato)lead(II)]

The crystal structures of the cadmium(II) and lead(II) complexes of phenoxyacetic acid (PAH) have been determined by single crystal X-ray diffraction techniques. The cadmium complex, [Cd(PA)₂(H₂O)₂] (1), space group C2, with Z = 2 in a cell of dimensions, a = 11.801(2), b = 5.484(1), c = 13.431(3) Å, β = 100.87(2)°, possesses a distorted trapezoidal bipyramidal coordination around the metal atom, involving two water oxygens [2.210(5) Å] and four carboxyl oxygens from two symmetrical bidentate phenoxyacetate ligands [2.363(4), 2.365(4) Å] with Cd lying on the crystallographic two- fold axis. The lead complex, [Pb₂(PA)₄(H₂O)]_n(2) is triclinic, space group P$\text{1}$, Z = 2, with a cell of dimensions, a = 10.135(4), b = 10.675(3), c = 19.285(9) Å, α = 114.66(3), β = 91.94(3) and γ = 114.99(3)°. (2) is a two-dimensional polymer with a repeating dimer sub-unit. The first lead [Pb(1)] has an irregular MO₈ coordination [2.34?2.96(2) Å: mean, 2.63(2) Å] involving the water molecule, two oxygens from an asymmetric bidentate carboxylate group, two from a bidentate chelate [O(ether), O(carboxylate)] group and three from bridging oxygens, one of which also provides a polymer link to another symmetry generated lead. The second lead [Pb(2)] is irregular seven-coordinate [PbO, 2.48?2.73(2) Å: mean, 2.61(2) Å] with three bonds from the bridging groups, two from an unsymmetrical bidentate carboxylate (O, O′) group and one from a second carboxyl group which also bridges two Pb(2) centres in the polymer.     

Synthesis of a new class of polydentate ligands: [bis(2-imidazolyl)methyl] amino-thioether-thiols

A new class of polydentate bis(imidazole)-thioether-thiol polydentate ligands has been synthesized by the reactions of functionalized primary amines with bis(2-imidazolyl)nitromethane. The molecules contain a bis(2-imidazolyl)methylamino group attached to chains of varying length with thiol (3, 23) and thioether/thiol (7,11,15,19) binding sites.     

Synthesis and optical study of Ln(III)(tetramethylurea)(AsF6)3 (Ln = LaLu,Y) and crystal structure for Ln = Eu [Eu(TMU)6(AsF6)3]

The fluorescence spectrum of Eu³⁺ recorded at a temperature of 12 K between 14.000 and 20.000 cm^?1 shows transitions from the excited stare ⁵D_o to the Stark components of the lowest ⁷F_j. The optical analysis suggests an octahedral site symmetry for the rare earth ion which is confirmed by the three-dimensional crystal determination. The highly disordered crystal structure refined in space group F23 to an R-factor of 13.2%. Both the europium and the arsenic ions are located in special positions of point symmetry 23(T). The EuO bond distance is 2.28 Å. The value of the B_q^k parameters was determined.     

Tetrakis-[1-methylimidazoline-2(3H)-thione]-μ2-[1-methylimidazoline- 2(3H)-thione]-Di-Copper(I) sulphate trihydrate: Preparation, thermal analysis and crystal structure

1-emthylimidazoline-2(3H)-thione (mimtH) reacts with copper(II) sulphate pentahydrate in aqueous acetone to produce the dinuclear complex, Cu₂(mimtH)₅SO₄ · 3H₂O; the formula has been established by a combination of chemical and thermal analysis. The monoclinic crystals, (space group P_c, Z = 2), contain dinuclear cations, sulphate ions and water molecules. The dinuclear cation, Cu₂(mimtH)₅²⁺, consists of two trigonal copper(I) atoms, four terminal, monodentate, S-donating mimtH molecules and one S-bridging (μ₂) mimtH molecule. Some average dimensions are:Cu---S, 2.258 Å and S---Cu---S, 120.0°; the Cu---S---Cu bridging angle is 94.8° and the Cu---Cu separation distance is 3.308 Å.     

Antitumor activity and metal complexes of the first transition series. Trans-bis(salicylaldoximato)copper(II) and related copper(II) complexes,a novel group of potential antitumor agents

The antitumor activity of forty nine different metal complexes of the first transition series against mouse leukemia L 1210 cells and of two of the complexes against Ehrlich ascites carcinoma have been tested in vitro by the method described in this paper. Eight complexes showed a 50% inhibition of tumor cell division at concentration level 5–6 μg/ml of the complex for the former and two most effective complexes also for the latter. The trans-bis-(salicylaldoximato)copper(II) and trans-bis(resorcylaldoximato)copper(II) complexes were found to possess the highest antitumor activity.