Ni(II) complexes with pyrazole-derived ligands. Crystal structures of [Ni(HL0)2ClH2O][Ni(HL0)2(H2O)2]Cl3·CH3OH·H2O and [Ni(HL1)2(H2O)2]Br2·2.5DMF (HL0=3-phenyl-5-(2-pyridyl)pyrazole and HL1=3-phenyl-5-(6-methyl-(2-pyridyl))pyrazole

The reaction of 3-phenyl-5-(2-pyridyl)pyrazole (HL⁰) and 3-phenyl-5-(6-methyl-(2-pyridyl))pyrazole (HL¹) with nickel(II) salts produces mononuclear coordination compounds. The new complexes have been characterised by elemental analyses, conductivity measurements and infrared and electronic spectroscopies.Two different forms of mononuclear nickel(II) complexes have been prepared and structurally characterised by X-ray crystallography: [Ni(HL⁰)₂Cl(H₂O)][Ni(HL⁰)₂(H₂O)₂]Cl₃·CH₃OH·H₂O and [Ni(HL¹)₂(H₂O)₂]Br₂·2.5DMF. In the cationic complexes, the coordination of the Ni(II) is octahedral with two bidentate HL⁰ or HL¹ neutral ligands in a cis disposition. The degree of distortion from regular octahedral geometry is compared to closely related structures. In the solid state, cations and anions are bonded by hydrogen bonding.     

Peculiarities of the crystal structure and packing of the host and guest molecules in the [M(4-McPy)4(NCS)2]·0.67(4-McPy)·0.33 H2O Clathrates (M = Cu(II), Mn(II); 4-MePy = 4-Methylpyridine)

The crystal structures of the two clathrates with the composition [M(4-MePy)₄(NCS)₂]·0.67(4-McPy)·0.33 H₂O (M=Cu(II), Mn(II); 4-MePy=4-methylpyridine) have been determined. These compounds are trigonal, with the [M(4-MePy)₄(NCS)₂] host molecules being centrosymmetric. The parameters of the unit cells area = 27.365(7) and 27.738(6),c = 11.303(9) and 11.250(8) Å,V = 7325(2) and 7493(2) ų, space group R , R = 0.053 and 0.109 for M = Cu(II) and Mn(II), respectively. ForZ = 9d _calcd is equal to 1.271 and 1.225 g/cm³, andd _measd is equal to 1.252(2) and 1.213(2) g/cm³ for the Cu and Mn clathrates, respectively. The coordination environment of the metal atoms in these compounds is an irregular octahedron, while in the Mn compound these distortions are rather small (Mn-N_MePy 2.30, 2.34 Å, Mn-N_NCS 2.18 Å, and Cu-N_MePy 2.06 Å, Cu-N_NCS 1.98 Å and Cu-N_MePy 2.50 Å).The molecular packing in the structures is such that the channels of variable diameter are formed along the short cell dimension (the maximum diameter is 10 Å, the minimum being 6 Å) where the guest 4-MePy and H₂O molecules are placed.     

HETERONUCLEAR COMPLEX CONTAINING COPPER-LANTHANIDE ARRAYS: THE SYNTHESIS AND CRYSTAL STRUCTURE OF Ln_2Cu_4L_8 (HL)_4(OH)_2(CIO_4)_4(H_2O)_(10)·2CH_3COCH_3 (Ln = Tb (1), Y (2); HL = 2-Pyridone C_5H_5NO)

Reaction of 2-pyridone, copper acetate and terbium(or yttrium) perchlorate in acetone with the moleratio 6: 2: 1 results in the formation of heteronuclear complex Ln_2Cu_4L_8 (HL)_4 (OH)_2 (ClO_4)_4 (H_20)_(10)2CH_3COCH_3(Ln = Tb (1), Y (2)). By recrystallizing (1) in CHCl_3 single crystals were obtained and thestructure was determined by four-circle diffractometer. Data showed that the crystal is in space groupC2/m with a=27. 454(9)A, b=13, 608A, c=30. 556(11)A, β=99. 89(3)°, v=11245. 7(7. 5)A~3. Thestructure was solved by a combination of Patterson method and Fourier technique. The final R value is0. 103. In the structure, four copper and two terbium ions are bridged by 2-pyridone anions to form anessentially octahedral Cu_4Tb_2 core. The terbium atoms are each eight-coordinate and the copper atomsare five-coordinate.     

Zinc(II) and cadmium(II) complexes having racemic and enantiomeric ligands: [Zn(La)2](NO3)2 · CH3CH2OH and [Cd(Lb)2Cl](ClO4) (La = D,L and Lb = D-(+)-1,2, 2-trimethylcyclopentane-1,3-diamine)

Two d¹⁰ transition-metal complexes having racemic and enantiomeric 1,2,2-trimethylcyclopentane-1,3-diamine ligands, [Zn(L_a)₂](NO₃)₂ · CH₃CH₂OH (1) and [Cd(L_b)₂Cl](ClO₄) (2) (L_a = D,L-1,2,2-trimethylcyclopentane-1,3-diamine, L_b = D-(+)-1,2,2-trimethylcyclopentane-1,3-diamine or (1R,3S)-1,2,2-trimethylcyclopentane-1,3-diamine), were synthesized and characterized by X-ray single-crystal diffraction. They crystallize in the Pbca and P2₁2₁2₁ space groups, respectively, and have different coordination numbers and coordination geometry (four-coordinate tetrahedron for Zn(II) in 1 and five-coordinate square-based pyramid for Cd(II) in 2) mainly due to their different ionic radii.     

Synthesis and crystal structures of yttrium sulfates Y(OH)(SO4), Y(SO4)F,YNi(OH)3(SO4)-II and Y2Cu(OH)3(SO4)2F·H2O

Y(OH)(SO₄), Y(SO₄)F, YNi(OH)₃(SO₄)-II and Y₂Cu(OH)₃(SO₄)₂F·H₂O are obtained from hydrothermal reactions at 380°C under a pressure of 210 MPa. Their crystal structures were refined from single-crystal X-ray diffraction data. The four compounds have the following space groups and unit cells: Y(OH)(SO₄), P2₁/n, a=7.9498(6), b=10.9530(9), c=8.1447(6) Å, β=93.764(1)°; Y(SO₄)F, Pnma, a=8.3128(9), b=6.9255(7), c=6.3905(7) Å; YNi(OH)₃(SO₄)-II, Pnma, a=6.9695(8), b=7.2615(8), c=10.292(1) Å; Y₂Cu(OH)₃(SO₄)₂F·H₂O, P2₁/n, a=11.6889(7), b=6.8660(4), c=12.5280(8) Å, β=97.092(1)°. The coordination environments of the yttrium atoms in the four structures vary from highly irregular 6+2, 6+3, 7+1 coordination polyhedra to relatively regular dodecahedra.     

New 1D and 2D metal oxygen connectivities in Cu(II) succinato and glutarato coordination polymers: [Cu3(H2O)2(OH)2(C4H4O4)2] · 4H2O, [Cu4(H2O)2(OH)4(C4H4O4)2] · 5H2O and [Cu5(OH)6(C5H6O4)2] · 4H2O

Two Cu(II) hydroxo succinates [Cu₃(H₂O)₂(OH)₂(C₄H₄O₄)₂]?·?4H₂O (1) and [Cu₄(H₂O)₂(OH)₄(C₄H₄O₄)₂]?·?5H₂O (2) and one Cu(II) hydroxo glutarate [Cu₅(OH)₆(C₅H₆O₄)₂]?·?4H₂O (3) have been prepared and structurally characterized by single crystal X-ray diffraction methods. They feature 1D and 2D copper oxygen connectivity of elongated {CuO₆} octahedra in “4?+?1?+?1” and “4?+?2” coordination geometries. Within 1, linear trimers of three edge-sharing {CuO₆} octahedra are connected into copper oxygen chains, which are bridged by the anti conformational succinate anions to generate 2D layers with mono terminally coordinating gauche succinate anions on both sides. The layers are assembled into a 3D framework by interlayer hydrogen bonds with lattice H₂O molecules distributed in channels. Different from 1, the principal building units in 2 are linear tetramers of four edge-sharing {CuO₆} octahedra. The tetramers are condensed into copper oxygen chains and the succinate anions interlink them into a 3D framework with triangular channels filled by lattice H₂O molecules. The {CuO₆} octahedra in 3 are edge-shared to form unprecedented 2D inorganic layers with mono terminally coordinating glutarate anions on both sides. Interlayer hydrogen bonding interactions are responsible for supramolecular assembly of the layers into a 3D framework with lattice H₂O molecules in the channels. The inorganic layers in 3 can be described as hexagonal close packing of oxygen atoms with the Cu atoms in the octahedral cavities. The title compounds were further characterized by elemental analyses, IR spectra and thermal analyses.     

Hexaaquacobalt(II) and hexaaquacadmium(II) 4-nitro-2,3,5,6-tetraoxopyridinates [M(H2O)6](C5HN2O6)2 · 2H2O (M = Co and Cd): Synthesis, structures, and properties

The complexes [Cd(H₂O)₆](C₅HN₂O₆)₂ · 2H₂O (I) and [Co(H₂O)₆](C₅HN₂O₆)₂ · 2H₂O (II) were obtained in the crystalline state by reactions of cobalt chloride and cadmium chloride with ammonium 4-nitro-2,3,5,6-tetraoxopyridinate, (NH₄)₂ · (C₅HO₆N₂)₂. Their cocrystallization gave the heterometallic complex [Cd_0.32Co_0.68(H₂O)₆](C₅HN₂O₆)₂ · 2H₂O (III). The crystal and molecular structures of complexes I-III were determined by X-ray diffraction. It was demonstrated that the complexation reactions occur by replacement of two ammonium cations 4-nitro-2,3,5,6-tetraoxopyridinate by the complex cations [M(H₂O)₆]²⁺. The tetraoxopyridinate anions and the complex cations are hydrogen-bonded through the coordinated and crystallization water molecules as well as through the O atoms of the organic anion. The thermolysis of complexes I and II was examined by TGA.     

Rare earth phosphate powders RePO4·nH2O (Re=La,Ce or Y) II. Thermal behavior

The thermal behavior, thermostructural and morphological changes, of rare earth phosphate powders RePO₄·nH₂O (Re=La, Ce or Y) was investigated up to 1500°C using high temperature X-ray diffraction, FT-infrared and Raman spectroscopies and thermogravimetry coupled with differential thermal analysis. The hydration water of the compounds was zeolitic (for Re=La or Ce) or coordinated (for Re=Y) and was associated with a divariant or a monovariant equilibrium of dehydration, respectively. The high temperature anhydrous monoclinic phase LaPO₄ or CePO₄ formed irreversibly at about 750°C after the total dehydration of the hexagonal hydrated structure while the dehydration of the monoclinic YPO₄·2H₂O phase began from about 190°C with its simultaneous decomposition into tetragonal YPO₄. A polytrioxophosphate secondary minor phase Re(PO₃)₃ resulting from adsorbed H₃PO₄ was formed at 950°C and decomposed at 1350°C. The particle morphology did not change with the temperature but grain coalescence occurred below 1000°C.     

Synthesis and Crystal Structure of an Ion-Pair Compound:[HL]2[Ni(CN)4]·4H2O(L=4-(2-Hydroxyphenyl)-1,5,9-triazacyclododecan-2-one)

An ion-pair compound,[HL]2[Ni(CN)4]·4H2O 1 has been obtained as an unexpected product when we attempt to prepare a heterometallic cyano-bridged complex by the reaction of GdCl3·nH2O,K2Ni(CN)4 and L (L=4-(2-hydroxyphenyl)-1,5,9-triazacyclododecan-2-one) in aqueous solution,and characterized by single-crystal X-ray diffraction.It crystallizes in monoclinic,space group P21/n with a=12.380(1),b=9.9637(8),c=17.087(1)A,β=105.947(2)°,V=2026.6(3) A3,Rint=0.0509,Z=2,Dc=1.297g/cm3,C34H56O8N10Ni,Mr=791.60,F(000)=844,μ(MoKα)=0.538 mm-1,S=1.030,the final R=0.0644 and wR=0.1299 for 2023 observed reflections with I≥2σ(I).The title compound 1 contains one anion of [Ni(CN)4]2-,two cations of [HL]+and four packing water molecules,which are held together by the N-H…O and O-H…O hydrogen bonds to form a three-dimensional framework.     

Cooperative and diminutive unusual weak bonding in F3CX···HMgH···Y and F3CX···Y···HMgH trimers (X = Cl, Br; Y = HCN, and HNC)

MP2 calculations with cc-pVTZ basis set were used to analyze intermolecular interactions in F(3)CX···HMgH···Y and F(3)CX···Y···HMgH triads (X = Cl, Br; Y = HCN, and HNC) which are connecting with three kinds of unusual weak interactions, namely halogen-hydride, dihydrogen, and σ-hole. To understand the properties of the systems better, the corresponding dyads are also studied. Molecular geometries, binding energies, and infrared spectra of monomers, dyads, and triads were investigated at the MP2/cc-pVTZ computational level. Particular attention is given to parameters such as cooperative energies, cooperative dipole moments, and many-body interaction energies. Those complexes with simultaneous presence of a σ-hole bond and a dihydrogen bond show cooperativity energy ranging between -1.02 and -2.31 kJ mol(-1), whereas those with a halogen-hydride bond and a dihydrogen bond are diminutive, with this energetic effect between 0.1 and 0.63 kJ mol(-1). The electronic properties of the complexes have been analyzed using the molecular electrostatic potential (MEP), the electron density shift maps, and the parameters derived from the atoms in molecules (AIM) methodology.     

Synthesis and characterization of cobalt(II) and manganese(II) xylaratogermanates: The molecular and crystal structures of the [M(H2O)6][Ge(μ3-L)2{M(H2O)2}2] · 4H2O · nCH3CN Complexes (M = Co, n = 0; M = Mn, n = 1)

A synthetic procedure was developed, and heteropolynuclear coordination compounds—the products of the interaction of germanium tetrachloride with xylaric (trihydroxyglutaric) acid HOOC-CH(OH)-CH(OH)-CH(OH)-COOH (H₅L) and the acetates of the 3d metals Mn(II) and Co(II)—were prepared. The compounds were characterized by elemental analysis, thermogravimetry, and IR spectroscopy. The X-ray diffraction analysis of the [M(H₂O)₆][Ge(μ₃-L)₂{M(H₂O)₂}₂] · 4H₂O · nCH₃CN complexes, where M = Co, n = 0 (I) and M = Mn, n = 1 (II), was performed. The crystals of I are monoclinic, a = 10.752(2) Å, b = 11.830(2) Å, and c = 10.772(2) Å, β = 94.741(3)°, V = 1365.4(5) ų, Z = 2, space group P2₁/n, R1 = 0.0309 for 3200 reflections with I > 2σ(I). The crystals of II are triclinic, a = 9.5330(17) Å, b = 9.7415(17) Å, and c = 10.3935(18) Å, α = 115.024(2)°, β = 97.580(3)°, γ = 111.535(3)°, V = 764.9(2)ų, Z = 1, space group $P\bar 1$ , R1 = 0.0621 for 3028 reflections with I > 2σ(I). The bimetallic anions [Ge(μ₃-L)₂{M(H₂O)₂}₂]^2?, the cations [M(H₂O)₆]²⁺, and crystal water molecules form the basis of compounds I and II (the acetonitrile molecule is also a constituent of compound II). In the centrally symmetrical trinuclear complex anion, the Ge(1) atom is bound to two M(1) atoms through two completely deprotonated bridging ligands. The Ge(1) atom is coordinated to the six alcohol oxygen atoms of two ligands L^5? at the apexes of a distorted octahedron (the average Ge(1)-O distances in I and II are 1.8858(14) and 1.892(3)Å, respectively). The coordination polyhedron of the M(1) atom in the complex anion is a strongly distorted octahedron. The base of the coordination polyhedron is formed by the two bridging alcohol oxygen atoms (the average M(1)-O distances in I and II are 2.1756(14) and 2.255(3) Å, respectively) of two L^5? ligands and by the oxygen atoms of two water molecules (the average M(1)-O distances in I and II are 2.0693(17) and 2.175(4) Å, respectively). In the centrally symmetrical complex cation, the coordination polyhedron of the M(2) atom is a somewhat distorted octahedron. The M(2)-O(H₂O) bond lengths in I and II vary in the ranges of 2.0137(17)-2.1555(17) and 2.140(5)-2.172(4) Å, respectively (the average lengths are 2.0375(17) and 2.166(4) Å, respectively). The cations and anions are joined by a branched system of hydrogen bonds.     

Cobalt(II) and copper(II)-diphenate complexes with 4-methylimidazole: linkage isomerism and weak C–H···Cu interaction

New Co(II) and Cu(II) diphenate complexes with 4-methylimidazole were synthesized and characterized through elemental analysis, magnetic susceptibilities, and IR spectroscopic studies. The crystal structures of [Co(dpa)(5-meim)₄]·2H₂O (1) and [Cu(dpa)(4-meim)(5-meim)₂]·H₂O (2) were determined by single-crystal X-ray diffraction (H₂dpa = diphenic acid, 4-meim = 4-methylimidazole and 5-meim = 5-methylimidazole). In 1, Co(II) has distorted octahedral geometry with four 5-meim and one diphenate ligands. Complex 2 has distorted trigonal bipyramidal geometry with one 4-methylimidazole, two 5-methylimidazole, and one diphenate ligands. In the complexes, the diphenate is coordinated to the metal(II) ions via the deprotonated oxygens of carboxylate as a bidentate ligand. The 4-meim and 5-meim linkage isomers within the same complex are found, and this complex is an unusual example. Moreover, another interesting feature of 2 is the presence of C–H···Cu weak hydrogen-bonding interactions.     

Concentration dependent tautomerism in green [Cu(HL¹)(L²)] and brown [Cu(L¹)(HL²)] with H₂L¹ = (E)-N'-(2-hydroxy-3-methoxybenzylidene)benzoylhydrazone and HL² = pyridine-4-carboxylic (isonicotinic) acid

The in situ formed hydrazone Schiff base ligand (E)-N'-(2-hydroxy-3-methoxybenzylidene)benzoylhydrazone (H?L1) reacts with copper(II) acetate in ethanol in the presence of pyridine-4-carboxylic acid (isonicotinic acid, HL2) to green-[Cu(HL1)(L2)]·H?O·C?H?OH (1) and brown-[Cu(L1)(HL2)] (2) complexes which crystallize as concomitant tautomers where either the mono-anion (HL1)? or di-anion (L1)2? of the Schiff base and simultaneously the pyridine-carboxylate (L2)? or the acid (HL2) (both through the pyridine nitrogen atom) function as ligands. The square-planar molecular copper(II) complexes differ in only a localized proton position either on the amide nitrogen of the hydrazone Schiff base in 1 or on the carboxyl group of the isonicotin ligand in 2. The proportion of the tautomeric forms in the crystalline solid-state can be controlled over a wide range from 1:2 = 95?:?5 to ～2?:?98 by increasing the solution concentration. UV/Vis spectral studies show both tautomers to be kinetically stable (inert), that is, with no apparent tautomerization, in acetonitrile solution. The UB3LYP/6-31+G* level optimized structures of the two complexes are in close agreement with experimental findings. The solid-state structures feature 1D hydrogen-bonded chain from charge-assisted O((-))H-N and O-H((-))N hydrogen bonding in 1 and 2, respectively. In 1 pyridine-4-carboxylate also assumes a metal-bridging action by coordinating a weakly bound carboxylate group as a fifth ligand to a Cu axial site. Neighboring chains in 1 and 2 are connected by strong π-stacking interactions involving also the five- and six-membered, presumably metalloaromatic Cu-chelate rings.     

Synthesis and dehydrogenation properties of NaZn(BH_4)_3·en and NaZn(BH_4)_3·2en(en= ethylene diamine)

Two new hydrogen storage compounds,Na Zn(BH_4)_3·en and Na Zn(BH_4)_3·2en(en=ethylene diamine)are synthesized by a solution method.They can release 6.4 wt% and 6.3 wt% pure hydrogen below 200℃,respectively,demonstrating the potential to be used as hydrogen carriers.Additionally,their dehydrogenation products,thermodynamics and kinetics are well characterized and analyzed.Results shows that the stronger Zn-N interactions and the Hδ~+–Hδ~- interactions are significant for their stability below 100℃,relatively low decomposition temperatures and elimination of gas impurities.     

Synthesis and X-Ray Crystal Structure of Two Novel Complexes: [M II(phen)3]2V4O12·phen·22H2O(M II=Co, Ni; phen=phenanthroline)

Summary. Two novel compounds, [Co(phen)₃]₂V₄O₁₂·phen·22H₂O (1) and [Ni(phen)₃]₂ V₄O₁₂·phen·22H₂O (2), were prepared from KVO₃–1,10-phenanthroline (phen)–Co(NO₃)₂, resp. NiCl₂–H₂O reaction systems. The compounds 1 and 2 are isomorphous and crystallize in triclinic system, space group P-1. Their crystal structures are formed by two types of layers parallel to 001: a cationic one consisting of [M^II(phen)₃]²⁺ ions and an anionic one containing the cyclic V₄O₁₂ ^4– anions. The solvate phenanthroline and crystal water molecules are located in the cationic and anionic layers, respectively. The IR spectra of 1 and 2 are consistent with the presence of the cyclic V₄O₁₂ ^4– anions in the complexes.Received November 13, 2002; accepted (revised) February 3, 2003 Published online June 2, 2003     

Synthesis,Crystal Structures and Magnetic Properties of Two Methoxo-Bridged Dimeric Copper(II) Complexes [Cu 2(APMD)4(μ2-OMe) 2 ]X 2(APMD = 2-aminopyrimidine; X = BF4 or CIO4)

Two bis-methoxo-bridged dimeric copper(II) complexes, [Cu₂(OMe)₂(APMD)₄](BF₄)₂ 1 and [Cu₂(OMe)₂(APMD)₄](ClO₄)₂ 2, were prepared and characterized by x-ray single-crystal structure analysis and magnetic susceptibility. Complexes 1 and 2 are isomorphous, being composed of discrete [Cu₂( w 2-OMe)₂(APMD)₄]²⁺ cations and anions with each Cu(II) atom ligated by two pyrimidine nitrogen atoms (Cu-N , 2.01Å) from two APMD ligands and two oxygen atoms (Cu-O , 1.92Å) from the w 2 -methoxo groups in a distorted square-planar geometry. The intramolecular metal-metal separations in the two complexes are ca. 2.95 Å. The intermediate antiferromagnetic exchanges (J , m 270 cm^-1) for the two complexes indicate a good overlap between the electronic orbitals of the square-planar copper(II) center via bridging oxygen atoms.     

Vibrational spectra of NH4-Ln(SO4)2·4H2O/D2O (LnLa and Ce)

Infrared and Raman spectra of NH₄Ce(SO₄)₂·4H₂O, NH₄La(SO₄)₂·4H₂O and the deuterated compounds NH₄Ce(SO₄)₂·4D₂O and NH₄La(SO₄)₂·4D₂O have been analysed. Splittings indicating the presence of two types of SO₄ ions are not observed. The SO bond strengths of the different SO₄ units are not significantly different. The SO₄ ion is distorted in these compounds. Deuteration causes changes in the SO₄ bond strength. Three crystallographically distinct water molecules exist in the unit cell.     

Cobalt(II) and nickel(II) complexes of N(4′) substituted 3- and 4-acetylpyridine thiosemicarbazones

Co^II and Ni^II complexes of N(4)-methyl and N(4)-ethyl thiosemicarbazones derived from 3- and 4-acetylpyridine have been prepared and characterized by microanalyses, magnetic susceptibility and molar conductivity measurements and by their electronic, i.r. and n.m.r. (in the case of Ni^II complexes) spectra.     

Syntheses and Crystal Structures of Two Supramolecular Architectures:(H_2tfbdc)·(tfbdc)·(Hbipy)_2 and (tfbdc)·(H_2pz)(tfbdc=Tetrafluoroterephthalate,bipy=4,4'-Bipyridine,pz=Pyrazine)

Two new supramolecular compounds,2C 10 H 9 N 2 + ·C 8 HF 4 O 4 2-·C 8 H 2 F 4 O 4 /(H 2 tfbdc)· (tfbdc)·(Hbipy) 2 (1) and C 4 H 6 N 2 2+ ·C 8 HF 4 O 4 2-/(tfbdc)·(H 2 pz) (2),were synthesized and characterized by elemental analysis,IR spectra,and single-crystal X-ray diffraction.Compound 1 crystallizes in the triclinic system,space group P1,with a=8.3453(12),b=10.1798(15),c=10.6626(16),α=87.591(2),β=74.047(2),γ=69.006(2)°,V=834.53(12) 3,D c=1.614 g/cm 3,F(000)=400,u=1.45 cm-1,Z=2,the final R=0.0353 and wR=0.1005 for 5882 observed reflections with I > 2σ(I);and compound 2 crystallizes in the monoclinic system,space group P2 1 /c,with a=10.471(4),b=5.4419(19),c=12.249(4),β=114.909(6)°,V=633(4)3,D c=1.669 g/cm 3,F(000)=320,u=1.63 cm-1,Z=2,the final R=0.0794 and wR=0.2923 for 3213 observed reflections with I > 2σ(I).Both compounds 1 and 2 crystallize as charge-transfer organic salts with the dianionic or neutral acid components lying at the inversion centers.Hbipy + cations and anionic acid in compound 1 are linked to form a chain by means of C-H···O hydrogen bonds.Adjacent chains are further extended into a two-dimensional layer network via N-H···O and O-H···N hydrogen bonds.In compound 2,the acid and base subunits are arranged alternately to generate a linear tape motif via N-H O hydrogen bonds;these tapes are further combined into a three-dimensional array with CdSO 4 topology via C-H O intermolecular hydrogen bonds.     

Synthesis,crystal structure and properties of the dimeric copper(II) complex, [Cu2(Hboa)2(H2O)2] · (ClO4)2 (H2boa = biacetyl oxime azine)

The crystal structure of the polyhydrazone dioxime-containing dimeric copper(II) (polyhydrazone dioxime: HON=CMe[CMe=NN=CMe] _n CMe=NOH) complex, [Cu₂(Hboa)₂(H₂O)₂] · (ClO₄)₂ (1) (H₂boa = biacetyl oxime azine) has been determined. Complex (1) contains an unusual six-membered ring, which is composed of two oxime groups and two Cu^II ions. The variable temperature magnetic susceptibility of (1) in the 5–300 K range has been interpreted in terms of a Cu^II dimer. The magnetic behavior shows that the bridging six-membered ring mediates very strongly in the antiferromagnetic exchange interaction, with the fitting value J = –361(1) cm^–1 and the e.p.r. g-value of 2.193.