Crystal structure and magnetic properties of catena-μ-(pyrazine-N,N′)bis[(p-nitrobenzoyl)trifluoroacetonato-O,O′]copper(II)

The X-ray crystal structure, variable-temperature magnetic susceptibilities and e.s.r. spectra are reported for the title complex. The complex crystallises as infinite chains in which the copper(II)-β-diketonate units are bridged axially by ambidentate pyrazine ligands with a Cu⋯Cu separation of 7.6700(2) Å. The magnetic susceptibility measurements in the range 5–325 K are consistent with the ferromagnetic intrachain exchange. The S=1/2 Heisenberg ferromagnetic linear chain analysis results in magnetic parameters of g=2.12 and J/k=0.6 K.     

Mercury(II) complexes of pyrrolidinedithiocarbamate,crystal structure of bis{[μ2-(pyrrolidinedithiocarbamato-S,S ′)(pyrrolidinedithiocarbamato-S,S ′)mercury(II)]}

Mercury(II) complexes of pyrrolidinedithiocarbamate (PDTC) having the general formula [Hg(PDTC)X] (X = Cl^?, SCN^?, and CN^?) and [Hg(PDTC)₂] have been prepared and characterized by elemental analysis, IR, and NMR. The crystal structure of [Hg(PDTC)₂] has also been determined by X-ray crystallography, showing that the complex is a centrosymmetric dimer, [Hg₂(PDTC)₄] (bis[µ²-(pyrrolidinedithiocarbamato-S,S′)(pyrrolidinedithiocarbamato-S,S′)mercury(II)]) (1). The solid-state structure of 1 contains two crystallographically equivalent Hg(II) centers in a distorted tetrahedron.     

Crystal structure of a new binuclear complex bis(2,4,6,8-tetramethyl-2,4,6,8-tetraazabicyclo(3.3.0)octane-3,7-dione-o,o′)-tetraaqua-hexakis(nitrato-o,o′)-dieuropium(III)

A centrosymmetric binuclear complex of europium(III) nitrate with bicyclic bisurea (2,4,6,8-tetramethyl-2,4,6,8-tetraazabicyclo(3.3.0)octane-3,7-dione, or mebicar, Mk) [Eu(C₈H₁₄N₄O₂)(H₂O)₂(NO₃)₃]₂ (I) is synthesized and its atomic structure (CIF file CCDC No. 1451437) is determined. The crystals of I are triclinic: space group \(P\overline 1 \), a = 9.8343(4) Å, b = 10.2544(4) Å, c = 10.9411(4) Å, α = 74.366(3)°, β = 67.734(4)°, γ = 67.673(4)°, V = 934.32(7) ų, ρ(calc.) = 2.03398 g/cm³, Z = 1. The europium atom is coordinated by two oxygen atoms of two Mk molecules connected by a symmetry operation, three bidentate nitrate anions, and two water molecules. The coordination polyhedron of the europium atom is a 10-vertex polyhedron, the Eu…Eu distance is 9.7433(6) Å.     

Crystal structure of di-μ-amido-bis[diammineplatinum(II)] nitrate

Di-μ-amido-bis[diammineplatinum(II)] nitrate (1) was synthesized as a byproduct during preparation of tetraammineplatinum(II) nitrate. One possible pathway to produce 1 is that [(H₃N)₂Pt(μ- OH)₂Pt(NH₃)₂](NO₃)₂, a well-known complex forming on treatment of cis-Pt(NH₃)₂I₂ with AgNO₃, reacts with aqueous ammonia. The other possible pathway involves deprotonation of [Pt(NH₃)₄](NO₃)₂ to form monomeric Pt(NH₃)₃(NH₂)NO₃ followed by elimination of NH3. Crystals of 1 (from water) are monoclinic (C2/c) with a = 16.834(2) Å, b = 10.573(1) Å, c = 7.415(1) Å, β = 114.846(1)°, and Z = 4. The cationic portion consists of two symmetrical square-planar Pt centers with the inversion center at the midpoint of the Pt(1)???Pt(1A) vector. The Pt(II) ion is coordinated by four N atoms from two ammonia molecules and two bridging amido groups affording a slightly distorted square. The molecules are stacked in such a way that the planes of coordination squares turn out to be parallel to each other with a distance of 3.501 Å. Intermolecular Pt–H interaction between the μ-NH₂ hydrogens and the platinum(II) centers of the adjacent molecule are observed.     

Crystal structure of octabutyl-μ-dichloro-μ3-dioxodichlorotetratin(IV)

An X-ray diffraction study has shown that Sn atoms in octabutyl-μ-dichloro-μ₃-dioxodichlorotetratin(IV) have distorted trigonal bipyramidal geometry with cis-equatorial butyl groups. Sn(1)C(but) and Sn(2)C(but) bonds are 2.077(21), 2.111(26) and 2.097(23), 2.114(22) Å, respectively. The distances of the triply-bridging O atom from Sn atoms are 2.151(9), 2.018(9) and 2.069(9) Å, and those of the bridging Cl atom are 2.666(5) and 2.831(6) Å. The distance Cl(term)Sn(2) is 2.426(5) Å. Refinement of the structure, based on 1828 observed reflections, converged to an R factor of 0.049 and a weighted R of 0.053. Crystal data for the compound are: a 13.672(6), b 19.529(9), c 8.999(2) Å, β 102.66(3) °, space group P2₁/c, Z = 2, M_r = 1105.49 for [Sn₄(C₄H₉)₈Cl₄O₂], V 2344(2) ų, D_x 1.464 gcm⁻³, F(000) = 1096, λ(Mo-K_α) 0.71069 Å,μ 22.1 cm⁻¹ and T 293 K.     

Crystal structure and spectroscopic properties of polymeric adducts of the tetra-μ-haloaspirinate-dicopper(II)

Eight new copper(II) complexes with halo-aspirinate anions have been synthesized: [Cu₂(Fasp)₄(MeCN)₂]?·?2MeCN (1), [Cu₂(Clasp)₄(MeCN)₂]?·?2MeCN (2), [Cu₂(Brasp)₄(MeCN)₂]?·?2MeCN (3), {[Cu₂(Fasp)₄(Pyrz)]?·?2MeCN} _n (4), {[Cu₂(Clasp)₄(Pyrz)]?·?2MeCN} _n (5), [Cu₂(Brasp)₄(Pyrz)] _n (6), [Cu₂(Clasp)₄(4,4′-Bipy)] _n (7), and [Cu₂(Brasp)₄(4,4′-Bipy)] _n (8) (Fasp: fluor-aspirinate; Clasp: chloro-aspirinate; Brasp: bromo-aspirinate; MeCN: acetonitrile; Pyrz: pyrazine; 4,4′-Bipy: 4,4′-bipyridine). The crystal structure of two 2 and 4 have been determined by X-ray diffraction methods. All compounds have been studied employing elemental analysis, IR, and UV-Visible spectroscopic techniques. The results have been compared with previous data reported for complexes with similar structures.     

Crystal structure of a trinuclear complex of zinc(II) with 2,6-Di-tert-butyl-p-quinone 1′-phthalazinylhydrazone

2,6-Di-tert-butyl-p-quinone 1′-phthalazynylhydrazone (HL) is synthesized; the total energies and geometry of the possible hydrazone tautomeric forms are calculated by quantum chemical methods. The hydrazone phthalazone tautomer is shown to be the most stable, which is well consistent with the ¹H NMR spectroscopic data for hydrazone. An X-ray crystallographic analysis is performed of the hydrazone-based Zn(II) trinuclear complex, in which zinc atoms are linked by the diazine bridge of the phthalazine cycle and two pivalate bridges. The geometric properties of the monodeprotonated hydrazone residue in the complex are similar to the calculated data for the phthalazone hydrazone tautomeric form.     

Bis(μ3-barbiturato−O,O,O′)-(μ2-aqua)- aqua-barium(II): crystal structure,spectroscopic and thermal properties

A polymeric coordination compound, [Ba(H₂O) ₂(Hba)₂] (1) (H₂ba – barbituric acid, C₄H₄N₂O₃), was obtained. The structure of 1 was solved using powder X-ray diffraction methods. The Ba²⁺ ion in 1 formed a three-capped trigonal prism. The BaO₉ polyhedra, connected with each other by the edges and faces, formed a chain. Several 4- and 12-membered cycles due to the bridging μ₂-H₂O and bridging μ₃-Hba^– also formed implementing a 3-D polymer structure. The structures of 1 and other thiobarbiturate complexes were compared. The replacement of a S atom by an O atom in the heterocyclic ligand Htba^? (thiobarbiturate ion) of the compound Ba(H₂O)₂(Htba)₂ resulted in changes of the coordination number Ba(II) and supramolecular structure. The intermolecular hydrogen bonds O–H?O and N–H?O formed a 3-D net where pronounced 2-D layers of Hba^– ions could be found. A new topological net in 1 was observed. The IR and thermal stability were investigated.     

Crystal structure of bis(α,α′-dithio-bis(formamidinium)) bis(μ2-chloro)hexachlorodimercurate(II)

The crystal and molecular structure of bis(α,α′-dithio-bis(formamidinium)) bis(μ₂-chloro)hexachlorodimercurate(II) C₄H₁₆Hg₂Cl₈N₈S₄ (I), where α,α′-dithio-bis(formamidine) is C₂H₆N₄S₂, was solved. Crystals are monoclinic, a = 8.6417(6) Å, b = 14.648(1) Å, c = 10.2111(8) Å, β = 104.949(1)°, V = 1248.8(2) ų, space group P2₁/n, Z = 4. The crystal structure is built of HgCl ₄ ^2? ions linked via inversion centers into [Hg₂Cl₈]^4? pairs and C₂H₈N₄S ₂ ²⁺ cations. [Hg₂Cl₈]^4? anions and C₂H₈N₄S ₂ ²⁺ cations form alternating layers linked by N-H…Cl hydrogen bonds into a framework structure.     

Crystal Structure of catena-[(Tetrakis-μ2-acetato-μ2-4,4'-bipyridine) dicopper(Ⅱ)] Acetonitrile Solvate

The title compound,[Cu2(CH3COO)4(C8H10N2)]n·nCH3CN1 (C8H10N2,4,4'-bipy = 4,4'-bipyridine),has been solvothermally synthesized in CH3CN and characterized by X-ray diffraction.The crystal is of monoclinic,space group Cc with a = 22.626(6),b = 14.012(4),c =15.106(4) (A),β = 107.610(3)°,V = 4565(2) (A)3,C20H23Cu2N3O8,Mr = 560.49,Z = 8,Dc = 1.631 g/cm3,μ = 1.914 mm-1,Flack parameter = 0.48(1),F(000) = 2288,R = 0.042 and wR = 0.)98 for 8887 observed reflections (I ＞ 2σ(I)).It consists of nearly linear one-dimensional chains [Cu2(CH3COO)4(C8H10N2)]n derived from paddle-wheel [Cu2(CH3COO)4] unit linked by 4,4'-bipy,and CH3CN as guest molecule regularly decorates between the chains.     

Crystal structure of hexakis(thiourea)-bis((μ-perchlorato-O,O’)-(perchlorato-O)-bismuth) diperchlorate

The complex[Bi₂(Tu)₆(ClO₄)₄](ClO₄)₂ (I) (Tu is thiourea) was synthesized and studied by X-ray diffraction. The crystallographic data of I are: a = 14.205(1) Å, b = 13.083(1) Å, c = 22.078(2) Å, β = 96.182(1)°, V = 4079.1(7) ų, space group C2/c, Z = 4. The molecule is located on a twofold axis and consists of the binuclear cation [Bi₂(Tu)₆(ClO₄)₄]²⁺ and two outer-sphere anions Cl ₄ ^? . The Bi-S bond lengths are 2.61–2.62 Å. For each terminal and bridging ClO ₄ ^? ion, one Bi-O distance varies from 2.744 to 3.048 3.269 structure contains a hydrogen bond network involving all hydrogen atoms. The IR and Raman spectroscopy data confirm the thiourea coordination by the sulfur atom.     

Structural isomerism of propionato copper(II) complex: crystal and molecular structure of tetrakis(μ-o-propionato)bis(methyl 3-pyridyl-N-carbamate)dicopper(II) at 190 K

The crystal and molecular structure of tetrakis(μ-o-propionato)bis(methyl 3-pyridyl-N-carbamate)dicopper(II) at 190 K was determined by X-ray analysis. The internuclear Cu⋯Cu distance is 2.6395(3) Å. CuO bond lengths are 1.961(1), 1.9678(9), 1.9828(9) and 1.9979(9) Å and CuN bond length is 2.165(1) Å. The non-bonding Cu(II)⋯Cu(II) contacts for nine binuclear Cu(II) propionates and hexacoordination of Cu(II) ion in the structure of [Cu(CH₃CH₂COO)₂(mpc)₂]0.25H₂O (mpc=methyl 3-pyridyl-N-carbamate) is consistent with the bond–valence sum model.     

Crystal structure and spectroscopic study of di-μ(1,1)-azido-di-μ(0,0-nitrato)tetrakis(3,5-lutidine)dicopper(II), [Cu(N3) (NO3) (3,5-lutidine)2]2

A mixed ligand 12 complex of copper(II) azide with 3,5-lutidine, namely di-(1,1)-azido-di(0,0)-nitrato)tetrakis(3,5-lutidine)dicopper(II) has been prepared and characterized by X-ray crystallographic and spectroscopic methods. The dimeric molecule, which possesses a crystallographic inversion center, contains two(1,1) bridging azido ligands. Each copper(II) atom in the cyclic Cu₂N₂ unit is further coordinated by two oxygen atoms from two(0,0-nitrato) bridges at Cu-O distances of 2.465(3) and 2.568(3) Å and two nitrogen atoms from the lutidine molecules [Cu-N=2.003(3) and 2.012(3) Å] to give a distorted tetragonal bipyramid. Both azido ligands are linear [N-N-N angle=179.0(4) and asymmetric N-N=1.207(4) and N-N=1.135(5) Å]. The azido bridges produce a rather short Cu Cu distance of 3.013(2) Å. Infrared and electronic data are presented and discussed.     

Crystal structure of copper(II) (+)-(S,S′)-α,α′-(9-OXO-l,5-diphenyl-3,7-diazabicyclo[3.3.1]non-3,7-ylene)dipropionate dihydrate

This paper reports on an X-ray diffraction study of the crystal and molecular structure of the dihydrate of the copper complex (II) of recently defined (+)-(S,S′)-α, α′-(9-OXO-1, 5-diphenyl-3,7-diazabi-cyclo[3.3.1]non-3,7-ylene)dipropionic acid (I). Crystals II are orthorhombic with unit cell dimensions a = 9.169(2), b = 17.591(2), c = 29.410(4) å, Z = 8 (C₂₅H₂₆(CuN₂O₅·2H₂O), space group P2₁(2₁(2₁ Structure II was solved by direct methods. Full-matrix least-squares anisotropic refinement converged to R = 0.033 for all 4523 measured independent reflections (CAD-4 automatic diffractometer, λCuK_α). The structure of II contains two symmetrically independent complex molecules, II and II'. which are similar in structure and linked into a dirtier by the Cu-O′ coordination bond. In both molecules, the Cu atom is pentacoordinated; its polyhedron is a distorted square pyramid with a base of two N atoms and two carboxylate O atoms and with an apex at the carboxylate O atom of the neighboring molecule II′ (in molecule II) or at the O atom of the water molecule (in molecule II′). The covalent bicyclic frameworks of II and II′ each consisting of two fused 6-membered rings have a chair-chair conformation, which is also typical for the noncoordinated molecules of compound I.     

Crystal and molecular structure of dicopper bis-(3-amino-5-methylisoxazole)tetraacetate [Cu2(μ-OCOCH3)2L2]

It was established by X-ray diffraction analysis that in the dimer complex of 3-amino-5-methylisoxazole (L) [ Cu₂(μ-OCOCH₃)₄L₂ ] the coordination bond is localized at the endocyclic pyridine type N atom. Arguments are given against other possible types of coordination in aminoisoxazole complexes conjectured from IR spectroscopy data in a number of publications. The dimer structure of the complex agrees with antiferromagnetic data (2J = -280 cm^-1 ). Translated fromZhurnal Strukturnoi Khimii, Vol. 41, No. 3, pp. 572-580, May–June, 2000.     

Synthesis,structure, and DNA-binding studies of a dicopper(II) complex with N-phenolato-N′-[2-(dimethylamino) ethyl]oxamide as ligand

A new µ-oxamido-bridged dicopper(II) complex, [Cu₂(pdmaeox)(bpy)(H₂O)](pic)?·?H₂O [H₃pdmaeox?=?N-phenolato-N′-[2-(dimethylamino)ethyl]oxamide, Hpic?=?2,4,6-trinitrophenol, bpy?=?2,2′-bipyridine], has been synthesized and characterized by elemental analyses, molar conductivity measurement, infrared, and electronic spectra studies, and X-ray single-crystal diffraction. The complex crystallizes in the triclinic system, P 1 space group, with crystallographic data: a?=?10.7815(2)?Å, b?=?11.3598(2)?Å, c?=?14.1389(3)?Å, and z?=?2. In [Cu₂(pdmaeox)(bpy)(H₂O)]⁺, one copper(II) resides in the inner site with a square-planar coordination geometry and the other is chelated by the two exo-oxygen atoms of the cis-pdmaeox^3? ligand in a square-pyramidal environment. The Cu···Cu separation through cis-pdmaeox^3? bridge is 5.1834(4)?Å. The crystal structure is stabilized by hydrogen bonds and π–π stacking interactions. The interaction of the dicopper(II) complex with herring sperm-DNA (HS-DNA) has been investigated by electronic absorption titration, fluorescence titration, electrochemical titration, and viscosity measurements. The results reveal that the interaction of the dicopper(II) complex with HS-DNA might be electrostatic binding. The effects of bridging ligand on the interaction of the dinuclear complex with HS-DNA were preliminarily investigated.     

Bis-(tetraethylammonium)[tetraazidocuprate(II)] and catena-di-μ-1,1-azido-[di-μ-1,1-azido-bis-(2,4-dimethylpyridine)dicopper(II)]

Two new copper(II) azido complexes, namely bis-(tetraethylammonium)[tetraazidocuprate(II)] (1) and catena-di--1,1-azido-[di--1,1-azido-bis-(2,4-dimethylpyridine)dicopper(II)] (2), have been prepared and characterized by spectroscopic and crystallographic methods. Complex (1) consists of isolated NEt⁺ ₄ cations and [Cu(N₃)₄]^2– anions. The site symmetry around the copper atom in the anion is 4/m. Complex (2) features a 1 D chain structure, five coordinated square pyramidal copper(II) atoms with both azides functioning as -1,1-bridges. The i.r. spectra reveal that both complexes contain asymmetric azido ligands. The solid and solution electronic spectra of (1) and (2) show very strong absorption bands in the visible region associated with N^– ₃ Cu^II charge-transfer transitions. The e.p.r. spectra of powder samples and solutions at room temperature were recorded and discussed.     

Infinite sheet structure of disodium tetra-μ-acetato- dichlorodirhodate(II) tetrahydrate

The binuclear rhodium(II) complex Na2[Rh2Cl2(OAc)4]· 4H2O has an infinite sheet structure. Binuclear anionic complexes [Rh2Cl2(OAc)4]2– are bound with cationic entities. The Na+ cation has pseudooctahedral coordination and is surrounded by two chloro ligands and two oxygen atoms of bridging acetato ligands of two [Rh2Cl2(OAc)4]2– anions and two water molecules. Both Cl and H2O are bridging ligands involved in formation of the Na+ chains. The remaining water molecules are located between sheets.     

The crystal and molecular structures of di-μ-hydroxy-bis(di-2-pyridylamine)dinitratodicopper(II) and aqua-μ-formato-triformato-bis(di-2-pyridylamine)dicopper(II) monohydrate

The preparation, magnetic and spectroscopic properties, crystal and molecular structures of binuclear complexes of formulae [Cu₂(dpyam)₂(OH)₂(ONO₂)₂] (I), [Cu₂(dpyam)₂(O₂CH)₄(OH₂)].H₂O (II) are described. (I) consists of pairs of copper atoms linked by two hydroxo bridges. The co-ordination geometry at each copper atom is distorted square-pyramidal, the basal plane consisting of two hydroxo oxygen atoms and two nitrogen atoms from a dpyam ligand, while the axial co-ordination sites are occupied by nitrate oxygen atoms. The copper(II) ions in (II) are also in a distorted square-pyramidal environment. They are bridged by a formate group in an anti–syn configuration from a basal position to an axial position, while another axial position is occupied by the water oxygen atom. From magnetic susceptibility measurements at room temperature, both complexes are found to exhibit antiferromagnetic interactions and some magneto-structural trends are discussed.