Synthesis and crystal structure of nickel(II) dinitrate molecular complex with 3,5-lutidine

Complex [Ni(NO₃)₂(3,5-lutidine)₃] (3,5-lutidine, 3,5-Lut-C₇H₉N) was synthesized, and its crystal structure was determined. Complex crystals are monoclinic: space group Cc, a = 14.445(1) Å, b = 10.024(1) Å, c = 17.607(1) Å, β = 108.96(1)°, V = 2411(1) ų, ρ_calcd = 2.389 g/cm³, Z = 4. The structure is built of discrete neutral complexes [Ni(3,5-Lut)₃(NO₃)₂]. The coordination sphere of Ni²⁺ ions is a disordered octahedron, which consists of three crystallographically nonequivalent lutidine ligands (Ni-N, 2.059–2.124 Å) and two oxygen ions of the two nitrate ions (Ni-O, 2.047–2.258 Å).     

Synthesis and crystal structure of bis(dimethylthioacetonedicarboxylate)nickel(II)

Summary The title compound has been synthesized and characterized. The crystal structure has been determined by single-crystal x-ray analysis from diffractometer data, and refined to R= 0.063 for 1889 observed reflections. Crystals are monoclinic, space group P2₁/n, witha=21.97(2),b=8.21(1),c=10.44(1) A, and =101.87(3), and Z=4. Both ligands are coordinated to nickel through sulphur and one oxygen atom to realize thecis form of the complex in the square planar coordination geometry. Bond distances are: Ni-S, 2.14(1), Ni-O, 1.87(1) and 1.90(1) Å. Each nickel atom also forms two close contacts with oxygen atoms from adjacent molecules.     

Synthesis and crystal structure of dinuclear nickel (Ⅱ) complex

The crystal structure of Ni(Ⅱ) complex with 3-hydroxyl-1, 5-diazacycloheptane-N, N'-diacetate was determined by X-ray diffraction method. Crystal data for Ni2 (C9H14N2O5)2·2H2O: monoclinic, space group P21/n, a = 1.1717(5), b = 0.9794(3), c = 1.2971(2) nm, β= 96.62(3), V= 1.4786(7) nm3, Dc = 1.377 g/cm3, Z = 2,μ=13.321 cm-1 (Mo-Kα), F(000)=640. The final R and Rw are 0.075 and 0.089 respectively. The Ni(Ⅱ) ion forms 2:2 complex with ligand. Two ligands are bridged by two Ni(Ⅱ) atoms which are bridged by two O atoms. Every Ni(Ⅱ) is coordinated by two N atoms and four 0 atoms. The coordination polyhedron of the Ni(Ⅱ) ion is a distorted octahedron.     

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).     

Synthesis and crystal structure of hydrated cation-anion nickel(II) thiosemicarbazide and nickel(II) malonate dihydrate complex

A crystal of Ni(HL)₂[Ni(Malon)₂(H₂O)₂]₂ · 3.51H₂O (I), which is built of [Ni(HL)₂]₂₊ cations (HL is thiosemicarbazide), [Ni(Malon)₂(H₂O)₂]_2? anions (H₂ Malon is malonic acid), and molecules of crystal water, has been synthesized and studied by IR spectroscopy, thermogravimetry, and X-ray diffraction. Structural units of complex I are linked by electrostatic interactions and numerous hydrogen bonds. The unit cell parameters b = 7.233(1) Å, c = 24.426(5) Å, β = 127.98(3)°, space group C2/c, Z = 8. The polyhedron of the nickel atom in [Ni(HL)₂]₂₊ cations is a cis-square that is slightly distorted within ～10°. Ligands HL are bidentately chelately coordinated (via N and S) to the nickel atom with the closure of near planar five-membered chelate rings. The malonate groups in [Ni(Malon)₂(H₂O)₂]^2? anions are bidentately chelately coordinated with the formation of six-membered non-planar chelate rings. The coordination of the central atom is complemented to an octahedron with two H₂O molecules. The bond lengths in cations are 1.924(4) and 1.912(4) Å (Ni-N) and 2.144(1) and 2.150(2) Å (Ni-S), and the bond lengths in anions are 2.003–2.046(3) Å (Ni-O) and 2.113(4) and 2.122(3) Å (Ni-O(w)).     

The crystal and molecular structure of diaquadichlorotheophyllinecopper(II)

Summary The crystal structure of CuCl₂(C₇H₈N₄O₂)(H₂O)₂ has been determined from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares to R=0.067 for 2123 observed reflections. Unit cell constants are:a=9.930(8),b=9.987(8),c=7.483(6) Å,=123.2(1),=94.5(1),= 83.9(1)°. The space group is P¯1 withZ=2. The structure consists of diaquadichlorotheophyllinecopper(II) complexes linked by hydrogen bonds. The coordination polyhedron of copper is a square pyramid whose base, severely tetrahedrally distorted, is formed by a water molecule [Cu-Ow=2.025(7) Å], two chlorines [Cu-Cl=2.273(4), 2.296(4) Å] and an imidazole nitrogen [Cu-N=1.983(9) Å] from the theophylline ligand. A second water molecule is at the apex of the pyramid [Cu-Ow=2.292(7) Å]. Coordination is completed to a distorted octahedral one by a long Cu ... O=3.164(7) Å contact involving the exocyclic oxygen at C₆ of the theophylline ligand.     

Coordination molecular compounds of cadmium(II) iodide with dimethylpyridines

The reactions of CdI₂ with dimethylpyridines (Me₂Py is C₇H₉N) afford complexes CdI₂(2,3-Me₂Py)₂] (I), [CdI₂(2,6-Me₂Py) (II), and CdI₂(3,5-Me₂Py)₂ (III). The structures of compounds I and II are determined. The crystals of complex I are orthorhombic, space group Pbca, a = 7.930(1) Å, b = 15.537(1) Å, c = 29.943(1) Å, V = 3689.1(5) ų, ρ_calcd = 2.090 g/cm³, Z = 8. The crystals of complex II are monoclinic, space group C2/c, a = 14.784(1), b = 11.991(1), c = 17.711(1) Å, β = 90.39(1)°, V = 1081.1(2) ų, ρ_calcd = 2.908 g/cm³, Z = 4. The structure of compound I is built of discrete neutral complexes [CdI₂(2,3-Me₂Py)₂]. The Cd polyhedron is a distorted tetrahedron (Cd-I 2.289–2.295, Cd-N 2.708–2.734 Å, angles N(I)CdN(I) 103.1°-114.8°). Polymer chains [CdI₂(2,6-Me₂Py)]_∞ extended along the direction [100] are observed due to the bridging iodine atoms in structure II. The Cd polyhedron is a trigonal bipyramid containing iodine atoms at the axial vertices (Cd-I_aks 3.040 Å) and two iodine atoms and the nitrogen atom of the Me₂Py ligand in the equatorial plane Me₂Py (Cd-I_eq 2.840 Å, Cd-N 2.309 Å). The compounds in the solid state are photoluminescent.     

Characterization of some high-spin iron(II) complexes with urea derivatives. The crystal structure of dichlorotetrakis(thiourea)iron(II)

Summary Urea (ur), thiourea (tu) and diisopropylthiourea (diptu) form high-spin complexes with iron(II), for which⁵⁷Fe Mössbauer quadrupole splitting and spectroscopic data suggest an octahedral distorted geometry. The x-ray diffraction study on Fe(tu)₄Cl₂ confirms this geometry. The crystals are tetragonal, space groupP4₂/n witha=13.71,c=8.94 Å andZ=4. The molecules are centrosymmetric with two axial chlorine atoms (Fe-Cl=2.46 Å) and four equatorial sulfur atoms (Fe-S=2.61 and 2.57 Å respectively). A similartrans-octahedral geometry is proposed for the new Fe(diptu)₄Cl₂ complex and an octahedral metal coordination in the new [Fe(ur)₆]Br₂, Fe(tu)₃Br₂ and Fe(ur)₃Br₂ complexes.     

Synthesis and crystal structure of bis(2,2,2-cryptand potassium) tetrakis(isocyanato)cuprate(II)

A new complex compound, bis(2,2,2-cryptand potassium) tetrakis(isocyanato)cuprate(II), 2[K(Crypt-222)]⁺ [Cu(NCS)4]^2? was prepared and its crystal structure was studied by X-ray structural analysis. The structure includes one symmetrically independent complex cation [K(Crypt-222)]⁺ of a guest-host type and independent one half of [Cu(NCS)₄]^2? anion. Through the center of the anion passes crystallographic symmetry axis 2, the approximate point symmetry of the anion is D ₂, while the approximate point symmetry of the complex cation is D ₃. The coordination polyhedron of the [Cu(NCS)₄]^2? anion (four N atoms) conjugated with Cu²⁺ cation is a nonplanar square considerably screwed into a flattened tetrahedron. The K⁺ cation (coordination number 8) of the complex cation [K(Crypt-222)]⁺ is coordinated by all eight heteroatoms (6O + 2N) of the 2,2,2-cryptand ligand, and its coordination polyhedron can be described as bis-basecentered trigonal prism slightly screwed into an anti-prism.     

Synthesis and crystal structure of mononuclear nickel(II) trifloroacetate complex

Russian Journal of General Chemistry -     

Coordination compounds of cobalt(II), nickel(II), and zinc(II) valerates and benzoates with benzohydrazide

Coordination compounds of cobalt(II), nickel(II), and zinc(II) valerates and benzoates with benzohydrazide have been synthesized and characterized by elemental analyses, IR spectra, diffuse reflectance spectra, and thermogravimetric data.     

Synthesis and crystal structure of aqua(diaminobithiazole) (iminodiacetato)nickel(II) hydrate

Crystals of the title compound, [(C₆H₆N₄S₂)(C₄H₅NO₄)(H₂O)Ni]·H₂O, consist of the Ni(II) complex and lattice water. The Ni(II) complex adopts a distorted octahedral coordination geometry formed by an iminodiacetate anion (IDA), a diaminobithiazole (DABT) and a coordinated water molecule. A twisted configuration of DABT is the distinguishing feature in the complex, the dihedral angle between thiazole rings of DABT being 20.04(8)°. An aromatic stacking interaction occurs between thiazole rings from neighboring complex molecules, and is considered as the reason for the twisted configuration. The tridentate IDA dianion chelates to a Ni(II) atom in afacialconfiguration. A hydrogen bond network holds the complex molecules together to form a supramolecular structure.     

Preparation and crystal structure of a nickel (II)-Uranyl(VI) binuclear chelate

Summary The structure of the heterobinuclear complex of Ni²⁺ and [U02₂]²⁺ with the tetraanionic ligand derived from the condensation of 1,2-diaminoethane with o-acetoacetylphenol has been determined from diffractometer data and refined to R = 7.2%. The crystals are monoclinic, P21 /a, with = 20.65(2), b = 8.58(1), c = 14.68(2) Å and = 97.78(5); Z = 4. The ligand employed has two different coordination sets of atoms, N₂O₂ and O₂O₂, two oxygen atoms being common to both donor sets. In the complex the nickel ion, which is four coordinate but not square planar, is retained in the inner N₂O₂ chamber, whilst the uranyl ion is incorporated in the outer O₂O₂ chamber. A molecule of solvent is retained to preserve the preferred seven coordination of uranium.     

Coordination compounds of cobalt(II) and cadmium(II) with 2-amino-4-methylpyrimidine: Synthesis, crystal structure, and luminescent properties

The coordination compounds [CoL₂Cl₂] (I) and [CdL₂(H₂O)₂(NO₃)₂] (II) have been synthesized by the reaction of CoCl₂ · 6H₂O and Cd(NO₃)₂ · 4H₂O with L = 2-amino-4-methylpyrimidine (Ampym, C₅H₇N₃), and their structures have been solved. The crystals of complex I are triclinic, space group $P\bar 1$ , a = 5.627(1) Å, b = 11.191(1) Å, c = 12.445(1) Å, α = 81.00(1)°, β = 77.21(1)°, γ = 76.18(1)°, V = 737.7(2) ų, ρ_calcd = 1.567 g/cm³, Z = 2. The crystals of complex II are monoclinic, space group P2₁/c, a = 10.390(1) Å, b = 11.982(1) Å, c = 7.624(1) Å, β = 102.61(1)°, V = 926.1(2) ų, ρ_calcd = 1.760 g/cm³, Z = 2. Discrete [CoL₂Cl₂] moieties are realized in the structure of complex I. The cobalt atom is tetrahedrally coordinated to the two nitrogen atoms of crystallographically nonequivalent ligands L and two chlorine atoms (Co(1)-N_avg, 2.051(4)Å; Co(1)-Cl(1), 2.241(1) Å; Co(1)-Cl(2), 2.263 Å; bond angles at the cobalt atom lie within a range of 102.1°–118.6°). The complexes are linked into supramolecular zigzag chains by N-H...N(Cl) hydrogen bonds. In the structure of complex II, the Cd²⁺ ion (at the inversion center) is coordinated in pairs to the nitrogen atoms of ligand L and the O(NO₃) and O(H₂O) oxygen atoms. The coordination of the Cd²⁺ ion is distorted octahedral (Cd(1)-N(1), 2.341Å; Cd(1)-O(1), 2.340(4) Å; Cd(1)-O(4), 2.327(3) Å; bond angles at the cadmium atom lie within a range of 79.1°–100.9°). N-H...N hydrogen bonds link the complexes into supramolecular chains. These chains are linked into a supramolecular framework by the O-H...O hydrogen bonds between water molecules and NO₃ groups.     

The crystal and molecular structure of cyclopentadienyltin(II) chloride. The bonding of the cyclopentadienyl group in tin(II) compounds

The crystal and molecular structure of cyclopentadienyltin(II) chloride has been determined from three-dimensional X-ray data. The crystals are orthorhombic, space group Pc2₁n. The unit cell, of dimensions a = 5.711(5), b = 6.225(5), c = 17.24(2) Å, contains four molecules. The structure has been refined by full matrix least squares techniques to a final R value of 0.083 for 717 independent reflections. In the crystal unsymmetrical tin-chlorine bridges are present between the units of C₅H₅SnCl.It is suggested that in cyclopentadienyltin(II) compounds the cyclopentadienyl group occupies more than one coordination site as a result of the donation of π electron density from the cyclopentadienyl ring into an empty acceptor orbital of the tin atom having π symmetry.     

The molecular structure of two methylallylnorbornyl complexes of nickel(II)

The structures of two isomeric Ni^II complexes with different molecular configurations have been determined by X-ray diffraction studies.     

Synthesis and crystal structure of a phosphite nickel(II) 8-mercaptoquinoline complex

A monomeric trimethylphosphite nickel(II) complex of 8-mercaptoquinoline (Hmtq), [Ni(mtq)P(OMe)3]Cl, was synthesised and characterised by X-crystallography, FAB-MS and cyclic voltammogram measurements. The nickel(II) atom is co-ordinated via the S and N atoms of the mtq– entity, one P(OMe)3 ligand and one Cl– anion in a square-planar geometry. Two types of main fragment ions were observed in the FAB mass spectrum of the title complex: Cl– followed by P(OMe)3. The electrochemical behaviour of the title complex in MeCN solution with n-Bu4NBF4 (0.1molL–1) as electrolyte on the Pt electrode indicates that the reversible redox reaction [Ni(mtq)P(OMe)3]+ + e [Ni(mtq)P(OMe)]0 has occured in MeCN.