The first nickel(II) allogon of a ditertiary phosphine ligand: Preparation,spectral and crystallographic characterization of square-planar bis(diphenylphosphinomethyl)dimethylsilanedinitratonickel(II)

The reaction of nickel(II) nitrate with bis(diphenylphosphinomethyl)dimethylsilane in ethanol solution gives Ni(NO₃)₂ · (Ph₂PCH₂)₂SiMe₂, recrystallized as orange and violet crystals from dichloromethane. Vibrational, electronic spectral and magnetic measurements of the initial product indicate the presence of allogons, the first case involving nitrate anions or a ditertiary phosphine ligand. The structure of the orange crystals 1 was determined by single-crystal X-ray diffraction analysis. The crystals are monoclinic, space group P2₁/c with four molecules in a unit cell of dimensions a = 10.512(2), b = 15.821(5), c = 18.948(8) Å, β = 104.87(4)°. The structure was solved by the heavy-atom method and refined by full-matrix least-squares calculations to R = 0.029 for 2563 observed data. In the monomeric molecule the Ni atoms are square planar, with monodentate nitrate groups [NiO = 1.926(2) and 1.933(2) Å]. The bidentate phosphine ligand has a bite angle of 94.81(3)° and the NiP bond distances are 2.166(1) and 2.170(1) Å. The six-membered NiP₂C₂Si ring adopts a boat conformation.     

The structure of (dichloro) (DI-μ-acetato)(bis-triphenyl phosphine) dimolybdenum(II)

The title compound was obtained in crystalline form suitable for X-ray structure determination. It forms crystals in the monoclinic space group P2₁/c with two centrosymmetric molecules in a unit cell of dimensions, a = 10.888(1) Å, b = 10.182(2) Å, c = 17.929(4) Å, β = 104.33(1)°. The central Mo₂Cl₂(O₂C)₂P₂ core has effectively C_2h-symmetry with the following principal dimensions: MoMo = 2.091(1) Å, MoCl = 2.405 Å, MoP = 2.566(2) Å, MoO(av.) = 2.103[4] Å, MoMoP = 104.38(7)°, and MoMoCl = 116.23(8)°.     

Crystal structures of azido or thiocyanato-coordinated nickel(II) complexes with tridentate Schiff bases

A new azido-coordinated nickel(II) complex [NiL¹(N₃)] (1) and a new thiocyanato-coordinated nickel(II) complex [NiL²(NCS)] (2), where L¹ and L² are the monoanionic forms of Schiff bases 2-[(2-isopropylaminoethylimino)methyl]-6-methylphenol and 2-[(2-dimethlaminoethylimino)methyl]-6-methylphenol respectively, are prepared and structurally characterized by elemental analysis, IR spectra, and single crystal X-ray crystallography. Complex 1 crystallizes in the triclinic space group P-1 with unit cell dimensions a = 8.812(2) Å, b = 9.433(3) Å, c = 9.488(2) Å, α = 81.933(2)°, β = 69.925(2)°, γ = 84.591(2)°, V = 732.5(3) ų, Z = 2, R ₁ = 0.0291, and wR ₂ = 0.0734. Complex 2 crystallizes in the monoclinic space group P2₁/n with unit cell dimensions a = 7.4497(4) Å, b = 6.1933(3) Å, c = 31.5126(18) Å, β = 92.484(2)°, V = 1452.57(13) ų, Z = 4, R ₁ = 0.0307, and wR ₂ = 0.0668. The Ni atom in each of the complexes is coordinated by three donor atoms of the Schiff base ligand and by one N atom of the azide or thiocyanate ligand, forming a square planar geometry. The azide and thiocyanate anions readily coordinate to the complexes as secondary ligands.     

SYNTHESIS AND CHARACTERIZATION OF THE FORMAL Ni(III) AND Cu(III) COORDINATION COMPLEXES OF THE NEW 1,2-DITHIOLENE, 1,4-BUTANEDIYLDITHIOETHYLENE-1,2-DITHIOLATE

Abstract

The new 1,2-dithiolene, 1,4-butanediyldithioethylene-1,2-dithiolate, has been isolated. In addition, new monoanionic bis-complexes with nickel and copper have been prepared and isolated. The formal Ni(III) complex crystallizes in the orthorombic space group, P_bca, with a = 9.762(9), b = 12.53(2), and c = 23.166(3) Å, with 4 molecules in the unit cell. The structure was refined to an R = 9.01% (R_w = 8.95%). The formal Cu(III) complex crystallizes in the monoclinic space group, C_2/c, with a = 25.567(6), b = 8.011(3), c = 14.504(3) Å, and β = 106.17(2)° with 4 molecules in the unit cell. The structure refined to R = 4.2% with R _w = 4.3%. Comparisons to similar 1,2-dithiolenes suggest this ligand produces only modest structural and electronic differences when compared to the 1,3-propanediyldithioethylene-1,2-dithiolate complexes. The oxidation (to a neutral complex) and reduction (to a dianion) for the Ni(III) and Cu(III) complexes show large differences from those of maleonitriledithiolate. Other physical data are presented as well.     

Syntheses and crystal structures of copper(II) and nickel(II) complexes derived from 2-bromo-4-chloro-6-[(2-methylaminoethylimino)methyl]phenol

A new centrosymmetric mononuclear copper(II) complex [Cu(L)₂](ClO₄)₂ (I) and a new centrosymmetric mononuclear nickel(II) complex [Ni(L)₂(MeOH)₂](ClO₄)₂ (II), where L is the zwitterionic ligand 2-bromo-4-chloro-6-[(2-methylammonioethylimino)methyl]phenolate, have been prepared from the Schiff base 2-bromo-4-chloro-6-[(2-methylaminoethylimino)methyl]phenol with copper perchlorate and nickel perchlorate, respectively. The complexes were characterized by elemental analysis, infrared spectra, and single-cyrstal X-ray diffraction (CIF files CCDC nos. 1408054 (I) and 1407973 (II)). Complex I crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 7.7736(4), b = 21.608(1), c = 8.5194(4) Å, β = 93.907(2)°, V = 1427.7(1) ų, Z = 2, R ₁ = 0.0546, and wR ₂ = 0.1531. Complex II crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 21.324(3), b = 16.821(2), c = 9.425(1) Å, β = 90.114(2)°, V = 3380.5(7) ų, Z = 4, R ₁ = 0.0693, and wR ₂ = 0.1627. The Cu atom in I is in square planar coordination, and the Ni atom in II is in octahedral coordination.     

Metal-phenoxyalkanoic acid interactions—12: The crystal and molecular structure of μ-aqua-di-μ-[(2-chlorophenoxy)ethanoato-(O,O′)]-bis[(2-chlorophenoxy)-ethanoato-bis(pyridine)nickel(II)]-water (1/1)

The crystal structure of the pyridine adduct of nickel (2-chlorophenoxy)-ethanote, {[Ni₂(2-CPA)₄(py)₄(H₂O)] · H₂O}, has been determined from three dimensional X-ray data at 293 K. Crystals of the complex are triclinic, space group P$\text{1}$, with two dimers in a unit cell of dimensions a = 21.740(5), b = 14.312(7), c = 9.044(2)Å, α = 96.69(4), β = 84.99(4), γ = 101.20(3)°. The structure was solved by direct methods and refined to 0.059 for 2682 ‘observed’ reflections. The dimer consists of two face-to-face NiO₄N₂ octahedra joined at their apical positions by a bridging water molecule [Ni(1)-Ow; 2.14(1)Å; Ni(2)-Ow, 2.10(1)Å; Ni(1)-Ôw-Ni(2), 116.9(4)°]. Two bidentate carboxyl groups of the 2-CPA molecules bridge the other two corners of the triangular face while the other two 2-CPA ligands are unidentate [Ni-O, 2.05(1)Å (mean)]. The coordination about each Ni is completed by two cis-related pyridine nitrogens [Ni-N; 2.11(1)Å (mean)]     

Crystal and molecular structure of bis[tetracarbonyldiphenylphosphidomanganese(0)]

The crystal structure of bis[tetracarbonyldiphenylphosphidomanganese(0)] has been determined by an X-ray diffraction study. The complex crystallizes in the monoclinic space group P2₁/n with four molecules in a unit cell of dimensions, a 15.714(4), b 16.446(5), c 12.016(4) Å, and β 101.25(2)°. The molecule has approximately centrosymmetric bi-octahedral D_2h structure. Each manganese atom is bonded to two phosphorus atoms of μ-diphenylphosphide groups and four carbonyl carbon atoms. The separation of the manganese atoms is 3.690(1) Å.     

Crystal structure and electrical conductivity of nickel 6, 13-di (p-tolyl)-5, 14-dihydrodibenzo [b,i]-1,4,8,11-tetraaza [14]annulene Iodide (Ni (dtdbtaa)I2.58)

Single crystals of the title compound are monoclinic, space group P2₁/n with two formula units per cell of the following dimensions: a = 18.209, b = 19.076, c = 4.075 Å, β = 92.43°. The crystals show metallic conductivity along the needle axis from room temperature down to ca. 180 K , the maximum conductivity at room temperature being 455 (Ω cm)^?1. The unoxidized (iodine free) parent compound crystallizes n the monoclinic space group P2₁/c with 2 molecules per cell of dimensions: a = 4.988, b = 20.192, c = 11.871 Å, β = 94.41°.     

Crystal structure of bis(iso-maleonitril-edithiolate)nickel(II) benzylpiperidinium

Bis(iso-maleonitriledithiolate)nickel(II) benzylpiperidinium, [BzPid]₂[Ni(i-mnt)₂] (1) is prepared and characterized by elemental analyses, UV, IR, molar conductivity, and single crystal X-ray diffraction. It is found that 1 crystallizes in the monoclinic space group P2₁/n with a = 9.551(1) Å, b = 16.520(2) Å, c = 11.004(1) Å, β = 96.60(1)°, V = 1724.6(3) ų, Z = 2. Consolidate the stacking of the molecules The electrostatic interaction between [Ni(i-mnt)₂]^2? anions and [BzPid]⁺ cations consolidates the stacking of the molecules.     

3-Substituted Sydnone Derivatives. Structures of 3-Cyclohexylsydnone and of Two Forms of 3-(3-Pyridyl)sydnone

The crystal and molecular structures of three sydnone derivatives are reported. The compound 3-cyclohexylsydnone crystallizes in space group C2/c of the monoclinic system with sixteen molecules in a cell of dimensions a = 19.326 (3), b = 9.471 (2), c = 20.005 (4)Å, β = 106.85(1)°. The structure has been refined to a final value of 0.0581 for the conventional R-factor based on 2222 independent observed intensities. Form I of 3-(3-pyridyl)sydnone crystallizes in space group P2/n of the monoclinic system with eight molecules in a cell of dimensions a = 7.317(2), b = 9.283 (2), c = 20.891 (6) Å, β = 99.61(2)°. The structure has been refined to a final value of 0.0514 for the conventional R-factor based on 1208 independent observed intensities. Form II of 3-(3-pyridyl)sydnone crystallizes in space group P2₁/c of the monoclinic system with eight molecules in a cell of dimensions a=9.073 (2), b = 22.267 (5). c = 7.494(2)Å, β = 112.15 (2)°. The structure has been refined to a final value of 0.0462 for the conventional R-factor based on 1330 independent observed intensities. Each of the three structures contains two crystallographically independent molecules in the cell. In the case of 3-cyclohexylsydnone, one of the independent molecules exhibits disorder around the exocyclic bond at N(3). A comparison of bond lengths indicates that the (electron donating) cyclohexyl group brings about enhanced electron density in the N(3)-C(4) bond, and possibly in the N(3)-N(2) bond. All three structures studied here exhibit intermolecular hydrogen bonding involving C(4)-H(4)…O(6) interactions. Although there are no stacking interactions in the cyclohexyl derivative, there is evidence for such interactions in the 3-pyridyl derivatives.     

Carbonylierung von bis(triphenylphosphin)-platin(II)- und -palladium(II)-komplexen in gegenwart von aminen und α-aminosäureestern

The crystal structure of (C₅H₅)₃Pr·CNC₆H₁₁ was determined from single-crystal X-ray diffraction data. The monoclinic unit cell of dimensions a = 8.298(3), b = 21.66(1), c = 11.943(4) Å, and β = 104.98(3)° contains four molecules in general positions of space group P2₁/c. Each molecule is composed of three C₅H₅ rings in a nearly exact trigonal array, η⁵-bonded to the Pr atom at a distance of 2.53 Å to the centroid of each ring, plus a single CNC₆H₁₁ adduct attached to the Pr atom along the trigonal axis at 2.65 Å. The presence of a CN triple bond in the isonitrile moiety and the nearly linear CNC configuration add credence to the previous proposal that there is a pure donor bond from the isonitrile carbon to the metal atom.     

Study on two coordination compounds using semicarbazide (SCZ) as bidentate ligand: {[\hbox{Ni}(\hbox{SCZ})_{3}](\hbox{NO}_{3})_{2}} and {\hbox{Cu}(\hbox{SCZ})_{2}\hbox{Cl}_{2}}

Two coordination compounds have been synthesized using semicarbazide as ligand- ${[\hbox{Ni}(\hbox{SCZ})_{3}](\hbox{NO}_{3})_{2}}$ (1) and ${\hbox{Cu}(\hbox{SCZ})_{2}\hbox{Cl}_{2}}$ (2). (1) crystallized as the monoclinic, P2(1)/c space group, a = 10.832(2) Å, b = 9.980(2) Å, c = 13.801(3) Å, β = 102.89(3)°; (2) crystallized as the monoclinic, P2(1)/c space group, a = 7.541(1) Å, b = 9.275(1) Å, c = 6.875(1) Å, β = 101.48(1)°. In both compounds, semicarbazides coordinate to nickel(II) or copper(II) centers to form the 5-member ring system. With the intermolecular hydrogen bonds, molecules are linked together to form the three-dimensional packing diagrams. Thermal decomposition mechanisms of both compounds were predicted based on DSC, TG-DTG and FTIR analyses.     

Die kristall- und molekúlstruktur der dimeren dimethylaluminium- und dimethylgallium-N,N′-dimethylacetamidine [(CH3)2M(NCH3)2CCH3]2 (M = Al,Ga)

Dimethylaluminium- and dimethylgallium-N,N′-dimethylacetamidine (I and II) are doubly associated forming a puckered eight-membered ring. They crystallize isostructurally in the monoclinic space group P2₁/c with two dimers per unit cell. The lattice constants of I are a 8.187, b 7.266, c 14.778 Å, β 103.58° and those of II a 8.163, b 7.277, c 14.835 Å, β 103.46°. The MN and the NC bond lengths within the rings are nearly equal, their mean values are for I: AlN 1.925 Å, CN 1.330 Å and for II: GaN 1.979 Å, CN 1.335 Å. This is also true for the exocyclic bond lengths with average values AlC 1.975 Å, NC 1.474 Å, CC 1.509 Å (for I) and GaC 1.998 Å, NC 1.484 Å and CC 1.507 Å (for II). The metal atoms are tetrahedrally coordinated, and the distortion is only slight. The final R-values are 0.034 and 0.056, respectively.     

Syntheses, crystal structures, and fluorescence properties of Zinc(II) complexes with multi-dentate Schiff bases

Two new structurally similar mononuclear Schiff base zinc(II) complexes, [ZnBr(ClMP)] (I) and [ZnCl(NMP)] (II) (ClMP = 4-chloro-2-[(3-morpholin-4-ylpropylimino)methyl]phenolate; NMP = 4-nitro-2-[(3-morpholin-4-ylpropylimino)methyl]phenolate), and two new dinuclear Schiff base zinc(II) complexes, [Zn₂(EMP)₂I₂] (III), and [Zn₂(MPA)(CH₃OH)₂(N₃)₂] (IV) (EMP = 5-diethylamino-2-[(2-dimethylaminoethylimino)methyl]phenolate; MPA = N,N′-bis(3-methoxysalicylidene)propane-1,3-diamine), have been prepared and characterized mainly by single-cyrstal X-ray diffraction. Complex I crystallizes in the monoclinic space group P2₁/n with unit cell dimensions: a = 15.116(3), b = 9.465(1), c = 23.714(4) Å, β = 104.358(2)°, V = 3286.9(8) ų, Z = 8, R ₁ = 0.0439, and wR ₂ = 0.0736. Complex II crystallizes in the monoclinic space group P2₁/c with unit cell dimensions: a = 7.253(2), b = 16.652(4), c = 13.568(3) Å, β = 96.600(2)°, V = 1627.8(6) ų, Z = 4, R ₁ = 0.0417, and wR ₂ = 0.0809. Complex III crystallizes in the monoclinic space group C2/c with unit cell dimensions: a = 27.962(2), b = 8.246(2), c = 31.605(3) Å, β = 90.343(2)°, V = 7287.4(15) ų, Z = 8, R ₁ = 0.0721, and wR ₂ = 0.1709. Complex IV crystallizes in the monoclinic space group C2/c with unit cell dimensions: a = 20.483(3), b = 11.344(2), c = 14.909(3) Å, β = 131.650(1)°, V = 2588.6(7) ų, Z = 4, R ₁ = 0.0343, and wR ₂ = 0.0792. Each Zn atom in I and II are four-coordinated in a tetrahedral geometry by the NNO donor set of the Schiff base ligand and one halide atom. The Zn atoms in III are in square pyramidal coordination, and those in IV are in octahedral and tetrahedral coordination. Thermal stability and fluorescence properties of the complexes I and II have also been determined.     

Synthesis and crystal structure of diaquadibenzoatobis(nicotinamide)nickel(II)

A coordination compound of nickel(II) benzoate with nicotinamide [Ni(C₆H₅COO)₂(L)₂(H₂O)₂] (I) (L is nicotinic acid amide) is synthesized and studied by IR spectroscopy. Its crystal structure is solved by X-ray crystallography. The crystals of compound I are monoclinic: a = 7.152 Å, b = 18.266 Å, c = 10.341 Å, β = 109.24°, V = 1275.4 ų, Z = 2, space group P2₁/c. Structural units of a crystal of I are centrosymmetric octahedral complex molecules. The coordination environment of the Ni atom contains two O atoms (Ni-O(1) 2.066(2) Å) and two N atoms (Ni-N(1) 2.091(2) Å) of the monodentate-coordinated benzoate anions and nicotinamide molecules, respectively, as well as two O atoms of the H₂O molecules (Ni-O(1w) 2.110(2) Å).     

Crystal structures of 6-[(2-hydroxy-1,1-bis-hydroxymethyl-ethylamino)-methylene]-4-nitro-cyclohexa-2,4-dienone hydrate and 6-[(2-hydroxy-1,1-bis-hydroxymethyl-ethylamino)-methylene]-4-bromo-cyclohexa-2,4-dienone

Crystal structures of 6-[(2-hydroxy-1,1-bis-hydroxymethyl-ethylamino)-methylene]-4-nitro-cyclohexa-2,4-dienone hydrate (I) and 6-[(2-hydroxy-1,1-bis-hydroxymethyl-ethylamino)-methylene]-4-bromo-cyclohexa-2,4-dienone (II) have been determined. The crystals of I are monoclinic, a = 16.957(1) Å, b = 10.729(2) Å, c = 7.240(3) Å; β = 99.56(3)°, space group P2₁/c, Z = 4, R = 0.0492. The crystals of II are triclinic, a = 10.282(2) Å, b = 7.189(3) Å, c = 16.831(3) Å; α = 90.67(3)°, β = 100.10(3)°, γ = 95.87(3)°; space group P-1, Z = 4, R = 0.0591. The independent part of the unit cell of I contains one unique molecule and water of crystallization, while in II — two unique molecules A and B. C(CH₂OH)₃ fragment of the molecule B manifests the disordering of alcohol oxygen atoms. Both in I and II, the salicylidene fragment of the molecules exists in the quinoid tautomeric form.     

Crystal and molecular structure of two monoclinic forms of tricarbonyldiiodo[bis(dimethylphosphine)ethane]-tungsten(II)

There are two monoclinic crystal forms of the title compound. In the first, a 11.701(6), b 15.680(9), c 9.316(5) Å, β 95.36(5)°, Z 4, with 1 molecule in the asymmetric unit, spacegroup P2₁/n. In the second, a 25.772(14), b 15.514(13), c 17.432(14) Å, β 91.59(8)°, Z 16, with 4 molecules in the asymmetric unit, spacegroup P2₁/a. In this latter form crystals were twinned with hk0 common. Both structures were solved by Patterson and Fourier methods from diffractometer data and refined by least squares methods to R 0.072 for 2226 independent reflections and to R 0.063 for 3250 independent reflections respectively. The five independent molecules are seven-coordinate monomers with similar geometries, all are distorted capped octahedra with a carbonyl group in the capping position, two carbonyl groups and a phosphorus atom in the capped face and two iodine atoms and a phosphorus atom in the uncapped face. Bond lengths are compatible with values found in similar structures. In all molecules, the two WP bond lengths differ by about 0.06 Å, the longer bond being to the phosphorus atom in the uncapped face which is trans to a carbonyl group.     

A trinuclear Ni(II) cluster with two significantly different configurations in the solid state

A chelating bisoxime ligand, 2,2′-[(1,3-propylene)dioxybis(nitrilomethylidyne)]dinaphthol (H₂L), and its corresponding Ni(II) cluster {[NiL(H₂O)]₂(OAc)₂Ni} · 0.5MeOH · 0.5CH₃CN · H₂O (1) have been synthesized and characterized by elemental analyses, TG-DTA, IR, ¹H NMR and X-ray diffraction methods. The Ni(II) cluster is monoclinic, space group P2(1)/c with cell dimensions a = 9.400(2), b = 24.530(4), c = 25.350(3) Å and β = 92.823(3)°. In the Ni(II) cluster, there are two ligand moieties (which provide N₂O₂ donors), two acetate ions and two water molecules, which result in three slightly distorted octahedral geometries around the Ni(II) ions.     

Synthesis and crystal structure of Isotrithionedithiolato-bis(phenanthroline)zinc(II)

The synthesis of a mixed-ligand complex 1,3-dithiole-2-thione-4,5-dithiolato-bis(1,10-phenanthroline)zinc(II), [Zn(Dmit)(Phen)₂], is described. The crystals are monoclinic, space group P2₁/n, a = 11.868(2) Å, b = 13.122(3) Å, c = 17.010(3) Å, β = 102.01(3)°, Z = 4. The coordination polyhedron of the Zn(II) atom is an octahedron formed by two sulfur atoms of the Dmit ligand and four nitrogen atoms of the two Phen ligands. The complex is studied by IR and UV spectroscopy.     

X-ray crystal structure of the clathrate compound tetrakis[(benzonitrile)(triphenylphosphorane)nickel(0)] · 2 toluene · ~1 n-hexane · ~1 cycloocta-1,5-diene

The preparation and the chemical properties of the clathrate compound tetrakis[(benzonitrile)(triphenylphosphorane)nickel(0)] · 2 toluene · ~1 n-hexane · ~1 cycloocta-1,5-diene are described. The crystal and molecular structure of this compound were determined from X-ray diffractometer data. The structure was solved by direct and Fourier methods and refined by least-squares techniques to R = 0.117 for 3441 independent reflections. The crystals are monoclinic, space group P2₁, with Z = 2, in a unit cell of dimensions a 14.680(7), b 28.198(18), c 15.482(8) Å, β = 118.43(8)°. Eight (NiP(C₆H₅)₃ · NCC₆H₅) formula units are present as two tetrameric molecules in the unit cell. Each Ni atom of the tetramer is linked by σ bonds to a P and N atom and by π bonds to the NC group of another benzonitrile molecule. The coordination of the nickel atoms is roughly trigonal. The nickel and N atoms form an eight-membered ring with a boat conformation. The NCC groups of the benzonitrile residues are bent and the NC distances indicate a high degree of double bond character for all these bonds. The triphenylphosphorane groups adopt a “propeller”-like conformation. Four solvent molecules 2 toluene, 1 n-hexane, and ~1 cycloocta-1,5-diene per asymmetric unit are present in the unit cell.