Infrared study of νOD modes in isotopically dilute (HDO) isostructural compounds M(HCOO)2·2H2O (M=Mn,Fe,Co,Ni,Cu,Zn) with matrix-isolated guest ions (Cu in M(HCOO)2·2H2O and M in Cu(HCOO)2·2H2O)

The infrared spectra of isotopically dilute (matrix-isolated HDO molecules) isostructural compounds M(HCOO)₂·2H₂O (M=Mn,Fe,Co,Ni,Zn,Cu) are presented and discussed in the region of the OD stretching modes. According to the structural data the compounds under study are divided into two groups: in M(HCOO)₂·2H₂O (M=Mn,Ni,Zn) the H₂O(1) molecules form stronger hydrogen bonds as compared to H₂O(2); in M(HCOO)₂·2H₂O (M=Fe,Co,Cu) the H₂O(2) molecules form stronger hydrogen bonds as compared to the H₂O(1) molecules. The influence of the metal–water interactions (synergetic effect) and the unit-cell volumes (repulsion potential of the lattice) on the hydrogen bond strength within the isostructural series is discussed. The wavenumbers of the uncoupled OD stretching modes of the HDO molecules influenced by guest ions (Cu²⁺ ions matrix-isolated in M(HCOO)₂·2H₂O and M²⁺ ions matrix-isolated in Cu(HCOO)₂·2H₂O) are presented and commented. For example, the analysis of the spectra reveals that when Cu²⁺ ions are included in the structure of M(HCOO)₂·2H₂O the hydrogen bonds of the type M–OH₂OCHO–Cu are considerably weaker as compared to those of the same type formed when M²⁺ ions are included in the structure of Cu(HCOO)₂·2H₂O if the cations remain unchanged.     

Influence of the crystal field stabilization energy of metal(II) ions on the structural distortion of matrix-isolated SO4(2-) guest ions in selenate matrices

Infrared spectra of metal(II) selenate hydrates (MeSeO4.nH2O and Na2Me(SeO4)2.2H2O; n=6, 5, 4, 1; Me=Mg, Mn, Co, Ni, Cu, Zn, Cd) containing matrix-isolated SO42- guest ions are reported and discussed with respect to the S-O stretching modes 3 and 1. An adequate measure for the SO42- guest ion distortion is the site group splitting deltanuas (deltanuab and deltanuac in the case of a doublet and a triplet for 3, respectively; a, being the highest wavenumbered component of nu3) and deltanumax (the difference between the highest and the lowest wave numbered S-O stretching modes). It has been shown that the SO42- guest ion distortion depends on both the number of the sulfate oxygen atoms involved in coordinative bonds with the metal(II) ions and the electronic configuration of the metal(II) ions, i.e. their crystal field stabilization energy (CFSE) additionally to the site symmetry and the local potential at the lattice site of the host lattice. The SO42- guest ions matrix-isolated in MeSeO4.H2O (Me=Mn, Co, Zn) and in Na2Me(SeO4)2.2H2O (Me=Mn, Cu, Cd) exhibit three bands corresponding to the nu3 modes as deduced from the site group analysis and deltanuab approximately equal to deltanubc. When SO42- guest ions are incorporated in the triclinic Na2Me(SeO4)2.2H2O host lattices (Me=Co, Ni, Zn) the nu3 stretching region resembles a higher local symmetry of the SO42- guest ions (an approximate (A1 + E) splitting) than the crystallographic one (i.e. deltanuab>deltanubc instead of deltanuab approximately equal to deltanubc) and, hence, the ratio deltanuab/deltanubc has to be taken into account (the higher value of the ratio deltanuab/deltanubc, the weaker is the distortion of the SO42- guest ions). The SO42- guest ions incorporated in MeSeO4.nH2O (n=6, 5, 4) exhibit a higher local symmetry of the guest ions than that deduced from the site group analysis (D2d for the SO42- guest ions in MeSeO4.5H2O, MeSeO4.4H2O and in the monoclinic MeSeO4.6H2O host lattices and close to Td in the tetragonal MeSeO4.6H2O host lattices). The analysis of the infrared spectra of selenate host lattices containing SO42- guest ions reveals that the guest ions are stronger distorted when the adjacent metal(II) ions have CFSE not equal to 0. These ions are more resistant to angular deformations of the MeO6-octahedra (i.e. changes in the O-Me-O bond angles), thus facilitating the SO42- guest ion distortion as compared to those having CFSE=0 which allow stronger angular deformations of the respective metal octahedra. Infrared spectra of kieserite-type compounds MeSeO4.H2O (Me=Mn, Co, Zn) containing matrix-isolated SO42- guest ions and Me'2+ guest ions different from those of the host ions (i.e. Me'SO4.H2O in MeSeO4.H2O) are also presented and discussed (double matrix-spectroscopy).     

Pyrazolate-based copper(II) and nickel(II) [2 x 2] grid complexes: protonation-dependent self-assembly, structures and properties

The pyrazole-based diamide ligand N,N'-bis(2-pyridylmethyl)pyrazole-3,5-dicarboxamide (H(3)L) has been structurally characterised and successfully employed in the preparation of [2 x 2] grid-type complexes. Thus, the reaction of H(3)L with Cu(ClO(4))2.6H(2)O or Ni(ClO(4))2.6H(2)O in the presence of added base (NaOH) affords the tetranuclear complexes [M(4)(HL(4))].8H(2)O (1: M = Cu, 2: M = Ni). Employment of a mixture of the two metal salts under otherwise identical reaction conditions leads to the formation of the mixed-metal species [Cu(x)Ni(4-x)(HL)(4)].8H(2)O (x相似文献   

Inorganic-organic hybrids formed by P,P'-diphenylmethylenediphosphinate, pcp2-, with the Cu2+ ion. X-ray crystal structures of [Cu(pcp)(H2O)2] x H2O and [Cu(pcp)(bipy)(H2O)

Weakly coordinated [Cu(pcp)(H2O)n] complexes are formed in aqueous solution, at room temperature, by interaction of P,P'-diphenylmethylene diphosphinic acid (H2pcp) with copper(II) ions. However, heating of the solutions gives rise to the formation of two extended metal-oxygen networks of formulas [Cu(pcp)(H2O)2] x H2O, 1, and [Cu(pcp)(H2O)2], 2. In the presence of 2,2'-bipyridyl (bipy) the diamine derivative [Cu(pcp)(bipy)(H2O)], 4, has been isolated. Complex 1 easily loses water to form a monohydrated derivative [Cu(pcp)H2O], 3, whereas 2 is completely dehydrated after prolonged heating at 150 degrees C, under vacuum. The compounds 1 and 2 have substantially different solid-state structures as shown by X-ray powder diffraction spectra, IR spectra, and thermogravimetric analyses. Consistently, the two complexes cannot be directly interconverted and present different dehydration pathways. Rehydration of these materials in both cases allows quantitative formation of 1. X-ray analysis established that the structure of 1 consists of a corrugated two-dimensional layered polymeric array, where infinite zigzag chains of Cu centers and bridging phenylphosphinate ligands are linked together through strong hydrogen-bonding interactions; the structure of 4 consists of monodimensional polymers, where the hydrogen-bonding interactions play an essential bridging role in the extended architecture. In both structures the metal center displays a five-coordinate environment with approximate square pyramidal geometry, with the pcp ligand acting as bidentate and monodentate in 1 and solely as bidentate in 4. In 1 the coordination sphere is completed through water molecules; in 4, through water and diamine ligands. The thermogravimetric analyses of the complexes are compared with those of the related hybrids [M(pcp)(H2O)3] x H2O, where M = Mn, Co, or Ni, confirming that noncoordinated water molecules also play a basic role in determining the molecular packing.     

X-ray photoelectron spectra of complexes with 1-(D-3-mercapto-2-methylpropionyl)-L-proline and Ni(II), Cd(II) and Cu(I): synthesis and LAXS study of Cu(I) derivative

Metal complexes of general formula Na2M(CAP)2xH2O (with M = Cd(II) or Ni(II), x = 7 and 4, respectively, CAP = 1-(D-3-mercapto-2-methylpropionyl)-L-proline) and NaCuCAPx3H2O have been synthesized as amorphous compounds and studied by means of X-ray photoelectron spectroscopy (XPS). Cu(I) derivative has been studied by IR, XPS and large-angle X-ray scattering (LAXS). IR data and the chemical shift of core level signals suggest that CAP is bonded to the metal via the sulphur atom and the carbonylic oxygen. LAXS data confirm this finding and are consistent with a tetrahedral configuration around the copper ion. The CAP molecule is bonded through the sulphur and the carbonylic oxygen and two water molecules complete the coordination around the metal. The sodium ion exhibits a tetrahedral configuration and interacts with the carboxylic group and two water molecules. One of these is bridging bonded between copper and sodium. No metal-nitrogen bonds are present.     

Synthesis and structure of [2 x 2] molecular grid copper(II) and nickel(II) complexes with a new polydentate oxime-containing Schiff base ligand

A new polynucleating oxime-containing Schiff base ligand, 2-hydroxyimino- N'-[1-(2-pyridyl)ethylidene]propanohydrazone (H pop), has been synthesized and fully characterized. pH potentiometric, electrospray ionization mass spectrometric, and spectrophotometric studies of complex formation in H 2O/DMSO solution confirmed the preference for polynuclear complexes with 3d metal ions. Single-crystal X-ray diffraction analyses of [Ni 4( pop) 4(HCOO) 4].7H 2O ( 1), [Cu 4( pop-H) 4(HCOOH) 4].H 2O ( 2), and [Cu 4( pop-H) 4(H 2O) 4].9H 2O ( 3) indicated the presence of a [2 x 2] molecular grid structure in all three compounds but distinct configurations of the cores: a head-to-tail ligand arrangement with overall S 4 symmetry of the grid in the Cu (2+) complexes as opposed to a head-to-head ligand arrangement with (noncrystallographic) C 2 grid symmetry for the Ni (2+) complex. A cryomagnetic study of 3 revealed intramolecular ferromagnetic exchange between copper ions in the grid, while in 1, antiferromagnetic interactions between the metal ions were observed.     

Guanine-containing copper(II) complexes: synthesis, X-ray structures and magnetic properties

Three new compounds of formula {[Cu(gua)(H(2)O)(3)](BF(4))(SiF(6))(1/2)}(n) (1), {[Cu(gua)(H(2)O)(3)](CF(3)SO(3))(2).H(2)O}(n) (2) and [Cu(gua)(2)(H(2)O)(HCOO)]ClO(4).H(2)O.1/2HCOOH] (3) [gua = 2-amino-1H-purin-6(9H)-one] showing the unprecedented coordination of neutral guanine, have been synthesised and structurally characterized. The structures of the compounds 1 and 2 contain uniform copper(II) chains of formula [Cu(gua)(H(2)O)(3)](n)(2n+), where the copper atoms are bridged by guanine ligands coordinated via N(3) and N(7). The electroneutrality is achieved by uncoordinated tetrafluoroborate and hexafluorosilicate (1) and triflate (2). Each copper atom in 1 and 2 is five-coordinated in a distorted square pyramidal environment: two water molecules in trans positions and the N(3) and N(7a) nitrogen atoms of two guanine ligands build the basal plane whereas a water molecule fills the axial position. The values of the copper-copper separation across the bridging guanine ligand are 7.183(1) (1) and 7.123(1) A (2). is an ionic salt whose structure is made up of mononuclear [Cu(gua)(2)(H(2)O)(HCOO)](+) cations and perchlorate anions plus water and formic acid as crystallization molecules. The two guanine ligands in the cation are coordinated to the copper centre through the N(9) atom. The copper atom in 3 is four-coordinated with two monodentate guanine molecules in the trans position, a water molecule and a monodenate formate ligand building a quasi square planar surrounding. Magnetic susceptibility measurements for 1 and 2 in the temperature range 1.9-300 K show the occurrence of significant intrachain antiferromagnetic interactions between the copper(ii) ions across the guanine bridge [J = -9.6(1) (1) and -10.3(1) cm(-1) (2) with H = -J summation operator(i)S(i).S(i+1)].     

Synthesis, X-ray crystal structure and X-band EPR of [Cu(H(2)O)(2)(imH)(4)] x Sq single crystals

The copper salt [Cu(H(2)O)(2)(imH)(4)] x Sq has been synthesized at room temperature. Crystal structure of the [Cu(H(2)O)(2)(imH)(4)] x Sq (Sq is squarete dianion (C(4)O(4)(2-)) and imH is imidazole (C(3)H(4)N(2))) complexes has been investigated by single-crystal X-ray diffraction analyses and the environment of copper ion has been identified by EPR. The single crystal is triclinic with the space group P1. The unit cell dimensions of the crystals are a=9.317 Angstrom, b=9.958 Angstrom, c=12.130 Angstrom, alpha=69.99 degrees , beta=76.61 degrees and gamma=78.13 degrees . The unit cell contains two molecules. The Cu(II) atom has an octahedral arrangement in which the Cu(II) ion lies on the inversion canter and is coordinated by four imidazole ligands with the equatorial plane and two water molecules with the octahedral axial. The complex shows a normal magnetic moment and the single crystal EPR spectra consist of two sets of four hyperfine lines of copper. The ground wave function of the hole of the Cu(2+) is an admixture of d(x(2) - y(2)) and d(z(2)) states.     

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The infrared and Raman spectra of the light blue modification of anhydrous copper(II) formate, Cu(HCOO)₂, and copper(II) formate-d₂, Cu(DCOO)₂, are reported, as well as the Raman spectra of copper(II) formate tetrahydrate Cu(HCOO)₂ · 4H₂O and copper(II) formate tetrahydrate-d₈ Cu(HCOO)₂ · 4D₂O over a wide range of temperatures. In the latter two compounds, the fundamental formate modes, active in the Raman spectra, showed splittings when the phase transition temperature was traversed. These low-temperature Raman spectra were interpreted in terms of a P2₁ space group and prove that the phase transition not only involves an ordering in the orientation of the water molecules, but also displacements of the heavy atoms. Only a limited number of weak translational modes of the water molecules could be identified in the Raman spectra of the copper(II) formate tetrahydrate, and it is not possible therefore to determine exactly how ordering affects the Raman-active lattice modes of these molecules.     

A missing high-spin molecule in the family of cyanido-bridged heptanuclear heterometal complexes, [(LCu(II))₆Fe(III)(CN)₆]3+, and its Co(III) and Cr(III) analogues, accompanied in the crystal by a novel octameric water cluster

Three isostructural cyanido-bridged heptanuclear complexes, [{Cu(II)(saldmen)(H?O)}?{M(III)(CN)?}]-(ClO?)?·8H?O (M= Fe(III) 2; Co(III), 3; Cr(III) 4), have been obtained by reacting the dinuclear copper(II) complex, [Cu?(saldmen)?(μ-H?O)(H?O)?](ClO?)?·2H?O 1, with K?[Co(CN)?], K?[Fe(CN)?], and K?[Cr(CN)?], respectively (Hsaldmen is the Schiff base resulting from the condensation of salicylaldehyde with N,N-dimethylethylenediamine). A unique octameric water cluster, with bicyclo[2,2,2]octane-like structure, is sandwiched between the heptanuclear cations in 2, 3 and 4. The cryomagnetic investigations of compounds 2 and 4 reveal ferromagnetic couplings of the central Fe(III) or Cr(III) ions with the Cu(II) ions (J(CuFe) = +0.87 cm?1, J(CuCr) = +30.4 cm?1). The intramolecular Cu···Cu exchange interaction in 3, across the diamagnetic cobalt(III) ion, is -0.3 cm?1. The solid-state 1H-NMR spectra of compounds 2 and 3 have been investigated.     

Asymmetric Schiff Base (N 2 O 3 ) Complexes as Ligands Towards Mn(II), Fe(III) and Co(II), Synthesis and Characterization

Heterobi- and tri-nuclear complexes [LMM'Cl] and [(LM) 2 M'](M=Ni or Cu and M'=Mn, Fe or Co) have been synthesised. The heteronuclear complexes were prepared by stepwise reactions using two mononuclear Ni(II) and Cu(II) complexes of the general formula [HLM]·1/2H 2 O, as ligands towards the metal ions, Mn(II), Fe(III) and Co(II). The asymmetrical pentadentate (N 2 O 3 ) Schiff-base ligands used were prepared by condensing acetoacetylphenol and ethylenediamine, molar ratio 1 1, to yield a half-unit compound which was further condensed with either salicylaldehyde or naphthaldehyde to yield the ligands H 3 L 1 and H 3 L 2 which possess two dissimilar coordination sites, an inner four-coordinate N 2 O 2 donor set and an outer three-coordinated O 2 O set. 1 H NMR and IR spectra indicate that the Ni(II) and Cu(II) ions are bonded to the inner N 2 O 2 sites of the ligands leaving their outer O 2 O sites vacant for further coordination. Different types of products were obtained according to the type of metal ion. These products differ in stoichiometry according to the type of ligand in the parent compound. Electronic spectra and magnetic moments indicate that the structures of the parent Ni(II) and Cu(II) complexes are square-planar while the geometry around Fe(III), Mn(II) and Co(II) in their products are octahedral as elucidated from IR, UV-visible, ESR, 1 H NMR, mass spectrometry and magnetic moments.     

Crystal structure and EPR studies of mixed ligand complex of cobalt(II) with saccharin and ethylisonicotine

The tetraaquabis(ethylisonicotinate)cobalt(II) disaccharinate, [Co(ein)2(H2O)4].(sac)2, (CENS), (ein: ethylisonicotinate and sac: saccharinate) complex has been synthesized and its crystal structure has been determined by X-ray diffraction analysis. The title complex crystallizes in monoclinic system with space group P2(1)/c and Z=2. The Co(II) cations present a slightly distorted CoN2O4 octahedral environment, with equatorially coordinated water molecules and axially pyridine N-bound ethylisonicotinate ligands. The magnetic environments of Cu2+-doped Co(II) complex have been identified by electron paramagnetic resonance (EPR) technique. Cu2+-doped CENS single crystals have been studied at room temperature in three mutually perpendicular planes. The calculated results of the Cu2+-doped CENS indicate that Cu2+ ion substitute with the Co2+ ion in the host lattice. The angular variations of the EPR spectra have shown that two different Cu2+ complexes are located in different chemical environments, and each environment contains two magnetically inequivalent Cu2+sites in distinct orientations occupying substitutional positions in the lattice and show very high angular dependence. The cyclic voltammogram of the title complex investigated in dimethylformamide (DMF) solution exhibits only metal centered electroactivity in the potential range -1.0-1.25V versus Ag/AgCl reference electrode.     

Complex formation between phytic acid and divalent metal ions: a solution equilibria and solid state investigation

An investigation on the complex formation equilibria between divalent metal ions Me (with Me=Mn, Co, Ni, Cu, Cd, and Pb) and phytic acid (H(12)L) is presented. Experiments were performed through a potentiometric methodology by measuring, at 25 degrees C, the proton and, in some cases (Cu(2+), Cd(2+), and Pb(2+)), also the metal ion activity at equilibrium in solutions containing, besides the metal and the ligand, 3 M NaClO(4) as the ionic medium. Unhydrolyzed solutions of the metal ion at millimolar concentration levels were titrated with solutions of about 10 mM sodium phytate, until the formation of a solid phase took place (always at pH approximately 2.5, except in the case of Cu(2+), which formed soluble complexes up to pH approximately 3.3). Coulometry was employed to produce very dilute solutions of either Cu(2+), Cd(2+), or Pb(2+) of accurately known composition. The emf data were explained by assuming, in the acidity interval explored, the formation of the complexes of general stoichiometry MeH(5)L(5-) and Me(2)H(3)L(5-). Coordination compounds in the solid state were also synthesized and characterized by elemental analysis, thermal analysis, and ICP spectroscopy. The solids had a general stoichiometry Me(6)H (t)LCl (t). x H(2)O, with the following t and x values for each metal investigated: Me ( t; x) = Mn (4; 2); Co (4; 2); Ni (4; 2); Cu (2; 2.5); Zn (2; 1); Sn (6; 6).     

Order—disorder in compounds LiMe2+VO4

The crystallographic order between the Li⁺ and Me²⁺ ions in some compounds LiMeVO₄ (Me = Mg, Co, Ni, Cu, Zn) has been investigated by vibrational spectroscopy. The Li⁺ and Me²⁺ ions are disordered in the cobalt and nickel compounds and ordered in the copper and magnesium compounds.     

Neutral (bis-beta-diketonato) iron(III), cobalt(II), nickel(II), copper(II) and zinc(II) metallocycles: structural, electrochemical and solvent extraction studies

Neutral dimeric metallocyclic complexes of type [M(2)(L(1))(2)B(n)] (where M = cobalt(II), nickel(II) and zinc(II), L(1) is the doubly deprotonated form of a 1,3-aryl linked bis-beta-diketone ligand of type 1,3-bis(RC(O)CH(2)C(O))C(6)H(4) (R=Me, n-Pr, t-Bu) and B is pyridine (Py) or 4-ethylpyridine (EtPy)) have been synthesised, adding to similar complexes already reported for copper(II). New lipophilic ligand derivatives with R = octyl or nonyl were also prepared for use in solvent extraction experiments. Structural, electrochemical and solvent extraction investigations of selected metal complex systems from the above series are reported, with the X-ray structures of [Co(2)(L(1))(2)(Py)(4)] x 2.25CHCl(3) x 0.5H(2)O (R=Pr), [Co(2)(L(1))(2)(EtPy)(4)] (R=t-Bu), [Ni(2)(L(1))(2)(EtPy)(4)] (R=t-Bu), [Zn(2)(L(1))(2)(EtPy)(2)] (R=Me) and [Zn(2)(L(1))(2)(EtPy)(4)] (R=t-Bu) being presented. The electrochemistry of H(2)L(1) (R=t-Bu) and of [Fe(2)(L(1))(3)], [Co(2)(L(1))(2)(Py)(4)], [Ni(2)(L(1))(2)(Py)(4)], [Cu(2)(L(1))(2)] and [Zn(2)(L(1))(2)(Py)(2)] has been examined. Oxidative processes for the complexes are dominantly irreversible, but several examples of quasireversible behaviour were observed and support the assignment of an anodic process, seen between +1.0 and +1.6 V, as a metal-centred oxidation. The reduction processes for the respective metal complexes are not simple, and irreversible in most cases. Solvent extraction studies (water/chloroform) involving variable concentrations of metal, bis-beta-diketone and heterocyclic base have been performed for cobalt(II) and zinc(II) using a radiotracer technique to probe the stoichiometries of the extracted species in each case. Synergism was observed when 4-ethylpyridine was added to the bis-beta-diketone ligand in the chloroform phase. Competitive extraction studies show a clear uptake preference for copper(II) over cobalt(II), nickel(II), zinc(II) and cadmium(II).     

草酸根桥联的Cu_2~ⅡFe~Ⅲ、Ni_2~ⅡFe~Ⅲ、Co_2~ⅡFe~Ⅲ异三核配合物的合成、表征及抗菌活性

合成了 7种草酸根桥联的 Cu 2 Fe 、Ni 2 Fe 、Co 2 Fe 异三核配合物 [M2 Fe(C2 O4) 3Lx](Cl O4) ,(M=Cu,L=bpy,Me2 phen,NO2 phen,x=2 ;M=Ni,Co,L=bpy,Me2 phen,x=4 ) .经元素分析、摩尔电导和磁性的测定以及红外光谱和电子光谱等方法对这些配合物进行了表征 ,确定了配合物的组成和结构 .初步生物活性试验表明形成异三核配合物后其杀菌活性明显提高     

Synthesis and characterization of triphenylmethylphosphonium transition metal salts

Triphenylmethylphosphonium salts, [PPh3Me]aMXn (M=Cu2+, Co2+, Mn2+, Ni2+ Fe3+ Pb2+ and Hg2+; X=Cl or I; a=1 or 2 and n=3 or 4) prepared by reacting PPh3MeX with the metal dihalide in EtOH sol-utions, have been characterized by electronic, Raman, far i.r. and Mo¨ssbaur spectra and by their magnetic properties as well as by elemental analyses. The copper complexes [PPh3Me]2CuCl4 and [PPh3Me]2Cu3Cl8 were characterized by X-ray crystallography and the structures are described. Powder diffraction patterns have shown that the cobalt and manganese tetrachloride complexes are isomorphous. Investigation by d.s.c. measurements showed that the complexes exhibit structural phase transitions.     

Cobalt(II)-(dpyo)-dicarboxylate networks: unique H-bonded assembly and rare bridging mode of dpyo in one of them [dpyo = 4,4'-dipyridyl N,N'-dioxide

Polymeric networks, {[Co(dpyo)(ox)]}(n) (1), {[Co(dpyo)(fum)(H(2)O)(2)]}(n) (1) and {[Co(dpyo)(tp)(H(2)O)(2)] x [Co(H(2)O)(6)] x (tp) x (H(2)O)}(n) (3) [ox = oxalate dianion, fum = fumarate dianion, tp = terephthalate dianion and dpyo = 4,4'-dipyridyl N,N'-dioxide] have been synthesized and characterized by single crystal X-ray diffraction analyses. The structural determination reveals 1 and 2 are covalent bonded 2D networks of 4,4 topology and of these, complex 2 undergoes a H-bonding scheme resulting in a 3D supramolecular architecture. Complex 3 is a 1D coordination polymer built up by almost collinear hexacoordinated Co(ii), doubly bridged by a tp carboxylate group and a dpyo oxygen, which in combination with lattice [Co(H(2)O)(6)](2+), tp and water molecules shows an unprecedented 3D supramolecular network through H-bonding. In the polymer the dpyo shows novel mu-4,4 bridging mode towards the cobalt ion. Low temperature magnetic interaction reveals antiferromagnetic coupling in all of the complexes.     

草酸根桥联的CuⅡ2FeⅢ、NiⅡ2FeⅢ、CoⅡ2FeⅢ异三核配合物的合成、表征及抗菌活性

合成了7种草酸根桥联的CuⅡ2FeⅢ、NiⅡ2FeⅢ、CoⅡ2FeⅢ异三核配合物[M2Fe(C2O4)3Lx](ClO4),(M=Cu,L=bpy,Me2phen,NO2phen,x=2;M=Ni,Co,L=bpy,Me2phen,x=4).经元素分析、摩尔电导和磁性的测定以及红外光谱和电子光谱等方法对这些配合物进行了表征,确定了配合物的组成和结构.初步生物活性试验表明形成异三核配合物后其杀菌活性明显提高.     

The role of water in synthesised hydrotalcites of formula Mg(x)Zn(6 - x)Cr2(OH)16(CO3) x 4H2O and Ni(x)Co(6 - x)Cr2(OH)16(CO3) x 4H2O--an infrared spectroscopic study

Infrared spectroscopy has been used to characterise synthesised hydrotalcites of formula Mg(x)Zn(6 - x)Cr2(OH)16(CO3) x 4H2O and Ni(x)Co(6 - x)Cr2(OH)16(CO3) x 4H2O. The infrared spectra are conveniently subdivided into spectral features based (a) upon the carbonate anion (b) the hydroxyl units (c) water units. Three carbonate antisymmetric stretching vibrations are observed at around 1358, 1387 and 1482 cm(-1). The 1482 cm(-1) band is attributed to the CO stretching band of carbonate hydrogen bonded to water. Variation of the intensity ratio of the 1358 and 1387 cm(-1) modes is linear and cation dependent. By using the water bending band profile at 1630 cm(-1) four types of water are identified (a) water hydrogen bonded to the interlayer carbonate ion (b) water hydrogen bonded to the hydrotalcite hydroxyl surface (c) coordinated water and (d) interlamellar water. It is proposed that the water is highly structured in the hydrotalcite interlayer as it is hydrogen bonded to both the carbonate anion, adjacent water molecules and the hydroxyl surface.