EPR spectra of (L-aspartate)di(2-pyridyl)aminezinc(II) hydrate substitutionally copper(II) doped complex

The [(L-aspartate)di(2-pyridyl)aminezinc(II)]hydrate doped with traces of copper was prepared. Electron paramagnetic resonance spectra of the polycrystalline sample were recorded at room temperature by using the X-band of the EPR spectrometer. The observedg factors for the complex areg _‖=2.258 andg _⊥=2.066. TheA _‖ value is 165.10⁻⁴ cm⁻¹. The crystal and molecular structure of the complex are also reported. The complex crystallizes in the monoclinic system; space groupP2₁ witha=7.2053(11),b=10.447(2),c=10.812(2) Å, β=108.489(14)° andZ=2. The structure can be described in the crystal lattice as polymeric chains.     

Synthetic and structural studies of the trans bis(2-N-H-pyrrolylcarbaldimine) complexes of nickel(II) and palladium(II)

The molecular bis(2-N-H-pyrrolylcarbaldimine)nickel(II) and palladium(II) complexes are isolated in moderate yield (30–35%) from in situ assembly of the Schiff base with metal(II) salt, base, and pyrrole-2-carbaldehyde in aqueous ammonia solution. The nickel(II) complex, 1, is monoclinic, space group P2₁/c, with a=11.289(6) ?, b=5.611(3) ?, c=8.287(5) ?, β=111.620(6)°, and V=488.0(5) ?³ with Z=2, for d _calc=1.667 Mg/m³. The palladium analog, 2, is isomorphous, space group P2₁/c, with a=11.481(3) ?, b=5.5738(10) ?, c=8.276(2) ?, β=110.923(12)°, and V=494.7(2) ?³ with Z=2, for d _calc=1.965 Mg/m³. In both crystal structures, the metal resides on an inversion center. In the IR spectra, ν(C=N) appears at 1561 cm⁻¹ in 1, and 1557 cm⁻¹ in 2, while ν(N–H) shows at 3345 cm⁻¹ and 3335 cm⁻¹, respectively. The ¹H-nmr spectra reveal the C–H and N–H protons of the imine group as sharp and broad doublets, respectively, at 7.62 and 8.38 δ in 1 and at 7.92 and 9.73 δ in 2.     

Crystal structure and EPR spectrum of dimeric di-μ-azide-bis[cyanide(N,N-diethylethylenediamine)]-copper(II), [Cu(N3)(NCO)(diEten)]2

The title compound, [Cu(N₃)(NCO)(C₆H₁₆N₂)]₂, crystallizes in the space groupP2₁/n, witha=8.336(1),b=17.405(3),c=8.376(1) Å, β=109.73(2)^o andZ=4. The molecules are arranged as centrosymmetric dimers in which two azide ligands bridge neighboring copper ions in an asymmetric head-on fashion. The Cu(II) ion is coordinated to five nitrogen atoms which form a distorted tetragonal pyramid. At the pyramid base are the two N atoms of a diEten molecule [Cu−N=2.00(1), 2.130(9) Å], an azide end atom [Cu−N=1.99(1) Å] and a NCO group [Cu−N=1.93(1) Å]. At the pyramid apex is the other, inversion related, azide N atom in the dimer [Cu−N=2.38(1) Å]. This Cu−N contact links the monomers within a dimer. Neighboring dimers are coupled by weak N−H…O contacts. Single crystal EPR data at X-band show that the pair of resonances expected for neighboring, magnetically nonequivalents dimers, collapse into a single line, a signature of inter-dimers superexchange coupling. The observed crystal gyromagnetic tensor is used to disclose the electronic and magnetic structure around Cu(II) ions.     

Synthesis,Characterization and Crystal Structure of Bis(isothiocyanato)-bis(pyridine) Zinc(II) Crystal

Abstract  Bis(isothiocyanato)-bis(pyridine) zinc(II) crystal has been prepared at room temperature and characterized by elemental analysis, IR spectrum and X-ray single crystal determination. The complex crystallizes in monoclinic space group P2₁/m with unit cell parameters: a = 5.5786(3), b = 11.0587(5), c = 12.1616(6) ?, β = 96.776(3)°, V = 745.03(6) ?³, Z = 2, D _x  = 1.514 g cm⁻³. The X-ray structure determination has revealed that the crystal is centered-symmetrical and the crystallographic symmetry face runs the two isothiocyanate ligands and the Zn(II) cation. Index Abstract  The title compound, bis(isothiocyanato)-bis(pyridine) zinc(II), was synthesized by zinc compound, KSCN and C₅H₅N (pyridine) and its crystal structure was determined. Single crystal X-ray structure determination reveals that the crystal is centered-symmetrical, and the crystallographic symmetry face runs the two isothiocyanate ligands and the Zn(II) cation.      

Synthesis and characterization of carboxylate-bridged copper(II) dinuclear complex

The dinuclear copper(II) complex {[Cu(pmea)Cl][Cu(H₂O)₃Cl]}(Cl)·H₂O (1) (pmea =bis(2-pyridylmethyl)amino-2-ethanoic acid) has been synthesized and characterized. It crystallizes in the monoclinic system P2₁/c, a = 9.0057(11), b = 28.031(3), c = 8.5669(10) Å, β = 104.267(2)°, V = 2095.9(4) ų, Z = 4. Crystal structure of 1 reveals a syn-anti carboxylate-bridged dinuclear complex, in which the coordination environment around each copper atom exhibits a distorted square-pyramid. Magnetic susceptibility measurement for 1 exhibits a weak intermolecular antiferromagnetic exchange interaction with 2J = −1.17(9) cm⁻¹. The cyclic voltammogram of 1 gives one oxidation and two reduction processes.     

Crystal structure of a silver(I) complex with the 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid)

The reaction between freshly precipitated silver oxide Ag₂O and an aqueous solution of tetrabenzenecarboxylic acid H₄L leads to the anhydrous Ag₂H₂L complex. It crystallizes in the space groupP2₁/c, witha=6.457(1),b=8.180(1),c=9.982(1) Å, β=97.83(1)°,V=522.3(1) ?³,Z=2,d=2.976 g cm⁻³. This structure is a three dimensional polymeric network polymer without any silver...silver interaction. The silver environment is a bipyramid trigonal polyhedron with three short bond distances in the equatorial plane (Ag−O=2.255(2), 2.295(2), and 2.499(2) Å) and two longer bond distances in axial positions (Ag−O=2.558(2) and 2.617(2) Å). Thus, the silver polyhedron involves five different ligands. It is noteworthy that the (H₂L₂)²⁻ ligand is located around an inversion centre.     

Copper(II) and lead(II) complexes of 4,4′-bipyridine-<Emphasis Type="Italic">N,N</Emphasis>′-dioxide

Cu(II) and Pb(II) complexes of 4,4′-bipyridine-N,N′-dioxide have been prepared using a solvent-layering system. [Cu₂Cl₄(bpdo)₃(H₂O)₂] . 2(CH₃)₂SO (1) crystallises in P-1, a=8.731(2), b=8.943(2), c=14.408(3) ?, α=102.85(3), β=97.49(3), γ=109.77(3)°. The Cu(II) complex is a z-shaped discrete molecule with a DMSO molecule hydrogen bonded to the host through coordinated water molecule. Crystallisation of PbCl₂, PbBr₂ and PbI₂ with bpdo afforded isostructural 2D coordination polymers. [PbCl₂(bpdo)]_n is monoclinic, C2/c with a=16.3274(7), b=4.0708(1), c=18.6146(8) ?, β=93.73(1)°; [PbBr₂(bpdo)]_n is monoclinic, C2/c with a=16.403(3), b=4.2412(8), c=18.846(4) ?, β=92.59(3)° and [PbI₂(bpdo)]_n is monoclinic, C2/c with a=16.438(3), b=4.538(1), c=18.973(4) ?, β=91.04(3)°. The adjacent metal centres of these polymers are bridged by coordinated Cl⁻, Br⁻ or I⁻ anions as well as by bpdo ligands. These polymers possess no conventional hydrogen bonds.     

Solid-phase synthesis, crystal structure, and quantum chemical calculation of a molybdenum(II) complex with bis(diethyldithiocarbamate)

The complex Mo(Et₂dtc)₂ [Et₂dtc: bis(diethyldithiocarbamate)] was synthesized by solid-phase reaction at room temperature and characterized by elemental analysis, powder XRD, IR, ¹H NMR and TG/DTA. Its crystal structure was determined by X-ray single crystal diffraction. The crystals are monoclinic with space group P2₁/c, a=0.61800(12) nm; b=1.1540(2) nm; c=1.1610(2) nm; β=95.78(3)°; V=0.8238(3) nm³; D _c=1.582 g/cm³; Z=2 F(000)=400; μ=1.285 mm⁻¹; R=0.0703; wR=0.2330; GOF=1.060. The coordination geometry of Mo atom, by four S anions from Et₂dtc ligand, is that of a slightly distorted planar square. Furthermore, the optimized geometry, charge distribution, and thermodynamic functions were calculated by quantum chemical method.     

Structure of chlorohydroxonitrosyl(terpyridine)ruthenium(II) hexafluorophosphate

The title complex has the NO grouptrans to the hydroxyl ligand and the chloride ion in the plane of the tripyridyl ligand. The Ru−O and Ru−N(O) distances are 1.939(5) ? and 1.764(6) ?, respectively; the Ru−N−O bond angle is 171.7(6)⁰. These values are consistent with previously reported shortening of Ru−O distances whentrans to a linear NO ligand. The space group of the structure isP2₁/c, witha=9.7213(9) ?,b=13.9318(11) ?,c=14.523(4) ?, and β=105.820(13)⁰.     

Synthesis and Crystal Structure of a Novel Five-Coordinate Complex from Zinc(II) and 1,3-Bis[2-(2-Hydroxybenzylideneamino)phenoxy]propan-2-ol Ligand

Abstract  

A novel five-coordinate Zn(II) complex of 1,3-bis[2-(2-hydroxybenzylideneamino)phenoxy]propan-2-ol (BHBAPP), namely [Zn₂(BHBAPP)₂](Pic)₂ · C₂H₅OH (Pic = picrate) has been synthesized and characterized by elemental analyses, IR spectra and X-ray single-crystal diffraction. The complex crystallizes in the triclinic space group P−1 with cell constants a = 9.8145(9), b = 13.2398(12), c = 14.5058(13) ?; α = 86.4560(10), β = 82.7260(10), γ = 73.0570(10)°, Mr = 1596.08, V = 1,788.0(3) ?³, Z = 1, Dc = 1.482 g/cm³, F(000) = 822, μ = 0.760 mm⁻¹. The structure was solved by direct methods and refined to R = 0.0390 (wR ₂ = 0.0996). Examination of the structure shows the Zn atoms are coordinated to four oxygen atoms and one nitrogen atom from BHBAPP ligand to form a distorted trigonal bipyramidal geometry. Further, in the crystal structure [Zn(BHBAPP)]⁺¹ cations and picrate anions are linked together via hydrogen bonding interactions tightly forming a three-dimensional supramolecular. It must be pointed out that the picrate anions play a special role in increasing the dimensionality of the supramolecular architecture.     

Dichloro-{bis(Pyrazol-1-yl)}Palladium(II) Complexes: Structures of a DMSO Solvated Dichloro-{bis(3,5-Dimethylpyrazol-1-yl)Acetic Acid}Palladium(II) and Dichloro-{bis(3,5-Ditertbutylpyrazol-1-yl)Methane}Palladium(II)

Abstract  Two new palladium(II) complexes, dichloro-{bis(3,5-dimethylpyrazol-1-yl)acetic acid}palladium(II)PdCl₂(3,5-Me₂bpza)], (1) (3,5-Me₂bpza = 3,5-dimethylpyrazol-1-yl)acetic acid) and dichloro-{bis(3,5-ditertbutylpyrazol-1-yl)acetic acid}palladium(II), [PdCl₂(3,5-^tBu₂bpza)], (2a) [3,5- ^t Bu₂bpza = 3,5-ditertiarybutylpyrazol-1-yl)acetic acid] complexes, were synthesized from the reactions of pyrazol-1-yl ligands with palladium salts. Attempts to crystallize 2a led to a hydrolyzed product, dichloro-{3,5-ditertbutylpyrazol-1-yl}palladium(II) (2b), in which the acetic acid moiety in the ligand backbone of 1 is lost. Both complexes 1 and 2b have been characterized by single-crystal X-ray crystallography. Both complexes crystallized in triclinic system (P − 1 space group). The cell parameters are: complex 1 (a = 8.7960(14) Å, b = 16.238(2) Å, c = 16.430(2) Å, α = 78.038(10)°, β = 77.817(11)°, γ = 89.970(10)°) and complex 2b (a = 10.1492(2) Å, b = 12.4001(2) Å, c = 13.108(3) Å, α = 103.0690(10)°, β = 97.4120(10)°, γ = 107.2450(10)°). The asymmetric unit of 1 contains two crystallographic independent monomeric units of 1 and three molecules of DMSO solvent, whilst that of 2b has got one monomeric unit with one molecule of chloroform solvent. Index Abstract  Two palladium complexes, dichloro-{bis(3,5-dimethylpyrazol-1-yl)acetic acid}palladium(II), PdCl₂(3,5-Me₂bpza)], (1) (3,5-Me₂bpza = 3,5-dimethylpyrazol-1-yl)acetic acid) and dichloro-{bis(3,5-ditertbutylpyrazol-1-yl)acetic acid}palladium(II), [PdCl₂(3,5- ^t Bu₂bpza)], (3,5- ^t Bu₂bpza = 3,5-ditertiarybutylpyrazol-1-yl)acetic acid) complexes, were synthesized from the reactions of pyrazol-1-yl ligands with palladium salts. Attempt to obtain crystals of tertiarybutylpyrazolyl analogue led to hydrolysis, the crystal structure of the hydrolysis product was established by single crystal X-ray crystallography.      

Crystal Structure of Tetraphenylarsonium Diisothiocyanatodichlorocobaltate(II)

Abstract  

Tetraphenylarsonium diisothiocyanatodichlorocobaltate(II) was synthesized by metathetic pathway. It crystallizes in the monoclinic space group C 2/c with unit cell parameters, a = 13.510(4) ?, b = 15.873(5) ?, c = 22.809(7) ?, β = 105.743(6)°, V = 1,618(5) ?³ and Z = 4. X-ray crystal structure analysis reveals that the asymmetric unit contains one {(C₆H₅)₄As}⁺ cation and one half {Co(NCS)₂Cl₂}²⁻ anion, the latter lying on a crystallographic twofold axis. While each {Co(NCS)₂Cl₂}²⁻ anion exhibits hydrogen bonding interactions with eight arsonium cations; CH···π interactions between phenyl rings of arsonium cations is restricted to two such centers in the crystal structure.     

X-ray crystal structure oftrans-dichlorobis(2,4,6-collidine)-copper(II)

The X-ray crystal structure oftrans-dichlorobis(2,4,6-collidine)copper(II) has been determined. Dark blue crystals of the complex crystallize in the monoclinic space group P2₁/c, with cell dimensionsa=7.527(3),b=14.732(4),c=7.951(4)Å and=92.79(9)°;V=880.6(6)ų andZ=2. 949 unique reflections withI _net>3(I) on refinement afforded values ofR=0.041 andR _w =0.048.     

Synthesis and Crystal Structure of a Polymeric Cobalt(II) Complex with 1,2-bis(1,2,4-triazol-1-yl)ethane

Abstract The title complex [Co₂(bte)₃(NCS)₄(H₂O)₂] _n (bte = 1,2-bis(triazol-1-yl)ethane) has been prepared. Single-crystal X-ray analysis reveals that the complex crystallizes in space group P ī with a = 7.7962(2), b = 8.3407(4), c = 14.7735(5) ?, α = 86.835(2), β = 76.2031(9), γ = 80.583(3)°. The crystal consists of two discrete complexes, [Co(bte)(NCS)₂(H₂O)₂] and [Co(bte)₂(NCS)₂]. The structure of [Co(bte)(NCS)₂(H₂O)₂] consists of neutral chain containing Co(II) bridged by bte molecules. The six-co-ordination of Co²⁺ is achieved by means of two trans NCS⁻ ions and water molecules. The structure of [Co(bte)₂(NCS)₂] demonstrates a one-dimensional neutral chain through bte-bridge, in which the Co(II) atom is in a distorted octahedral environment formed by four nitrogen atoms of the triazoles and two nitrogen atoms from two trans thiocyanato liagnds. Index abstract Synthesis and Crystal Structure of a Polymeric Cobalt(II) Complex with 1,2-bis(1,2,4-triazol-1-yl)ethane This paper reports the synthesis and crystal structure of complex [Co₂(bte)₃(NCS)₄(H₂O)₂]_n (bte = 1,2-bis(triazol-1-yl)ethane), which consists two different neutral chains containing Co(II) bridged by bte molecules.      

Structure of dichloroethanolaminecopper(II) and dibromoethanolaminecopper(II)

CuCl₂(NH₂CH₂CH₂OH) is monoclinic, space group C2/c, witha+11.092(2),b+10.012(2),c+6.401(1) Å, =121.71(1)°, andV=604.8(2)ų withZ+4. The structure was refined to a final value ofR+0.27 for 518 unique observed reflections with |F|>3. The ethanolamine and halide ions coordinate to the copper(II) ion forming a pseudoplanar four-coordinate monomeric CuCl₂L² complex (L²+bidentate ligand). The copper ion also interacts with the halides of neighboring complexes through the formation of semi-coordinate Cu-Cl linkages (2.926(1) Å) between oligomers. The copper thus attains a 4+2 elongated octahedral coordination geometry. In this space group, the ligand is statisticallydisordered The Cu-Cl distance is 2.267(1)Å while the Cu-N/O distances are 2.025(2)Å. The dibromide structure is isomorphous with the dichloride structure, with space group C2/c, anda+11.285(2),b+10.218(2),c+6.715(1) Å, =121.65(1)°, andV=659.2(2)ų.     

Synthesis,Crystal Structure,Magnetic Properties of a Manganese(II) Coordination Polymer with Double-Helix Chains

Abstract  

A new heterocyclic carboxylate ligand, 5-(4′-pyridyl)-3-methyl-benzoic acid (Hpmba), was synthesized to construct a Mn(II) coordination polymer, namely [Mn(pmba)₂] _n (1). Complex 1 crystallizes in monoclinic space group C2/c, with a = 17.44(2), b = 17.040(12), c = 8.680(15) ?, β = 111.258(13), V = 2404(5) ?³, and Z = 4. Single-crystal X-ray diffraction studies show that complex 1 has a 3D metal-organic supramolecular framework consisting of double helical chains. Magnetic studies for complex 1 show antiferromagnetic coupling between the nearest Mn(II) ions, with g = 2.11 and J = −10.1 cm⁻¹.     

Structure of a five-coordinate mononuclear cobalt(II) complex: chlorobis([N,N-(1,1′-biphenyl-2,2′-dimethylene)]-2-aminomethyl) pyridine)cobalt(II) bromide

A penta-coordinate mononuclear cobalt(II) complex, [Co(BP)₂(Cl⁻)](Br⁻), 1 with a novel, biphenyl-appended N,N-bidentate ligand, BP ([N,N-(1,1′-biphenyl-2,2′-dimethylene)]-2-aminomethyl) pyridine) was synthesized and characterized by elemental analysis, UV-Vis, electro-spray ionization mass spectrum and single crystal XRD. The title complex crystallizes in the monoclinic space group C2/c with cell dimensions a = 11.389(2), b = 25.627(3), c = 12.276(3) Å, β = 100.419(18)° and Z = 2. The cobalt atom has a distorted trigonal bipyramidal (tbp) geometry and is surrounded by 4Ns of two BP, and a Cl⁻/Br⁻ at the 5th coordination site. This is the first report of a mononuclear tbp cobalt complex with biphenyl appended bidentate ligand containing amino-pyridyl moiety.     

Synthesis, characterization and crystal structure of [Ni(DACH)2](H2O)2(CH3COO)2 (DACH = 1,4-diazacycloheptane): a three-dimensional (3-D) hydrogen-bonded network embodying 1-D water chains

The mononuclear complex [Ni(DACH)₂](H₂O)₂(CH₃COO)₂ (DACH = 1,4-diazacyclo-heptane) has been synthesized and characterized by IR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The complex crystallizes in monoclinic system, P2₁/n space group with a=7.500(3) ?, b=8.788(3) ?, c=16.429(6) ?, β=93.395(5)°, D _c =1.269 g cm⁻³, μ=0.930 mm⁻¹, V=1080.9(6) ?³, Z=2. The central Ni^II atom is in a square-planar coordination geometry formed by four N atoms of two DACH chelated ligands. The notable feature of the title compound resides in the formation of a three-dimensional network through hydrogen bonds between the [Ni(DACH)₂]²⁺ cations, the CH₃COO⁻ counter anions and the guest water molecules trapped in the crystal lattice.     

Structural investigation of 1-amino-2,4,6-trinitrobenzenes in the solid state and in solution

The crystal structure of 1-pyrrolidino-2,4,6-trinitrobenzene3, 1-morpholino-2,4,6-trinitrobenzene4 and 1-piperidino-2,4,6-trinitrobenzene5 have been determined by single-crystal X-ray diffraction data and the structure in solution was investigated by UV-visible spectrophotometry and¹³C nmr. The three compounds are monoclinic, space groupP2_i/n. Unit cell dimensions area=6.6660(1),b=8.612(1),c=20.696(3) ?, β=90.73(1)^o, andD _c =1.58 g cm⁻³ for compound3;a=7.090(2),b=21.493(9),c=8.298(3) ?, β=101.27(1)^o, andD _c 1.60 g cm⁻³ for compound4 anda=10.426(1),b=10.038(1),c=12.291(1) ?, β=90.04(1)^o withD _c =1.53 g cm⁻³ for compound5 forZ=4. In the solid state, differences regarding the planarity of the aromatic ring in the three substrates were found. Rotation of theortho-nitro groups and of the amino group out of the aromatic plane was observed both in the solid state and in the solution. Greater coplanarity of the two rings was found in3 than in4 and5.     

Crystallographic and conformational analysis of 1,3-bis(2,4-dimethoxyphenyl)imidazolidine-2-thione

The molecular and crystal structures of the title compound, C₁₉H₂₂N₂O₄S, were determined by single crystal X-ray diffraction technique. The title compound crystallizes in space group F d d 2, with a = 30.785(3) ?, b = 10.6455(9) ?, c = 11.0036(8) ?, Z = 8, D _calc = 1.379(2) g cm⁻³, μ(Mo-K_α) = 0.207 mm⁻¹, and its crystal system is orthorhombic. The structure was solved by direct methods and refined to a final R = 0.042 for 1530 reflections with I > 2σ (I). There is a half-independent molecule in the asymmetric unit. The title molecule has twofold rotational symmetry along with the C–S bond. Classically no hydrogen bond is found in the crystal structure. The crystal structure is stabilized by π–π stacking and edge to face (C–H…π-ring) interactions. To elucidate conformational features and steric hindrances of the title molecule, selected torsion angle is varied from −180° to +180° in every 10° and thus molecular energy profile is calculated by PM3 semi-empirical method.Supplementary materials CCDC 261789 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, by emailing data_request@ccdc.cam.ac.uk, or by contacting The Cambridge Crystallographic Data Centre, 12, Union Road, Cambridge CB2 1EZ, UK; fax: $+$44 1223 336033.