Synthesis and characterization of novel heteronuclear complexes of Ln(Ⅲ)-Cu(Ⅱ) with non-cyclic polyether Schiff base

Nine novel heteronuclear complexes of Ln(Ⅲ)-Cu(Ⅱ) with salicylidene tetraethvlcne glycol diamine (SALTTA) have been synthesized and characterized.They have the general formulae [LnCu2(SALTTA)2(NO3)3](NO3)4 3H2O (Ln=La,Pr.Nd,Srn) and [LnCu3(SALTTA)3(NO3)5]-(NO3)4-4H2O (Ln=Gd,Tb,Er,Yb,Y).The IR spectra show that vc=N in the Ln(Ⅲ)-Cu(Ⅱ) het-eronuclear complexes are splitted up into two peaks with a far distance.It has been confirmed that oxygen atoms in oxyethylene of the ligand are not all coordinated to the central metal ions by both IR and NMR methods.     

Synthesis of La(Ⅲ), Y(Ⅲ) complexes with polyglycol aldehyde-amino acid Schiff base and their high resolution solid state ~(13)C NMR spectra

La(Ⅲ), Y(Ⅲ) complexes with diglycol aldehyde bis-arginine (H_2DAAR) and tetraglycol aldehyde bislysine (H_2TALY) Schiff bases were synthesized. They were characterized and formulated as La(H_2DAAR) (NO_3)_3·6H_2O and Y (H_2TALY)(NO_3)_3·5H_2O separately by elemental analyses. The obtained complexes were investigated in detail by high resolution solid state (HRSS) ~(13)C NMR using cross polarization, magic angle spinning (CPMAS), and total suppression of sidebands (TOSS)techniques. The results are supported by the liquid state 2D-~1H-~(13)C COSY NMR spectra. Some new information about the splitting peaks of ~(13)C for—CH=N—group and alkene carbon bands, etc. in HRSS ~(13)C NMR spectra are given.     

Studies on synthesis and magnetic resonance of lanthanide complexes with novel Schiff base derived from noncyclic polyether and P-diketone

Nine Ln( Ⅲ ) complexes with a novel Schiff base derived from diglycolamine and benzoylacetone (BZDA) have been synthesized and characterized. They can be formulated as [Ln2(BZDA)3(NO3)3](NO3)3· nH2O(Ln=La, Pr, Nd, Sm, n = 4; Ln=Gd, Tb, Er, Yb, Y, n = l). Enamic form mechanism in this β-diketone Schiff base and its complexes were suggested and proved by IR, UV and NMR methods. The 13C spin-lattice relaxation time T1 and the ratios of r(ci-Ln)/r(cj-Ln) were measured by a 500 MHz NMR instrument for elucidating the formation of the stable sk-membered chelate ring structure in these complexes. The EPR spectrum of the Gd( Ⅲ ) complex exhibits the "U" spectral feature and "zero field effect". On the basis of them, the crystal field strength and the local symmetry around Gd3 in the complex have been discussed.     

Synthesis, mechanism and NMR spectra of lanthanide complexes with a novel unsymmetrical Schiff base

Owing to its two unsymmetrical-NH_2 groups sited on different terminals, 2, 6-diaminocaproic acid (lysine) was used as a reactant for synthesizing a novel unsymmetrical Schiff base with salicylaldehyde on one side and ovanillin on the other for the first time. It is a new way to synthesize such a special unsymmetrical Schiff base. It is named "hetero bis-Schiff base" for distinguishing it from others. The synthesis method, formation mechanism as well as twelve new lanthanide complexes with the above ligand are reported and discussed herein. They were characterized by elementary analysis, molar conductivity, IR-spectra and especially by ~1H and ~(13)C NMR spectra. The results obtained may provide a new promising method for synthesizing similar unsymmetrical Schiff bases and their complexes.     

SYNTHESIS AND MAGNETISM OF BINUCLEAR COPPER(Ⅱ) COMPLEXES CONTAINING SALUCYLAMIDATOCUPRATE(Ⅱ)

New binuclear copper(Ⅱ) complexes, [Cu(samen)Cu(NO_2-phen)]·H_2O and [Cu(sampn)-Cu(NO_2-phen)]·2H_2O have been synthesized, where samen~(4-), sampn~(4-) and NO_2-phen denote N, N′-ethylenedisalicylamidate anion, N, N′-1, 2-propanedisalicylamidate anion and 5-nitro-1, 10-phenanthroline respectively. 3ased on IR, elemental analyses and electronic spectra, the complexes are proposed to have a phenoxy-bridged structure and to consist of the Cu(Ⅱ)ion in distorted planar environment. The complexes have been characterized with varlable-temperature magnetic susceptibility (4—300 K) and the observed data were fit to those from a modified Bleaney-Bowers equation by least-squares method, giving the exchange integral J=-63.0 cm~(-1) (samen) and J=-46.5cm~(-1) (sampn). This indicates the existence of antiferromagnetic spin exchange interaction among the metal ions.     

新型双核席夫碱配合物的合成及谱学性质

Eight novel binuclear tetradentate Schiff base complexes (M=Cu(Ⅱ),Ni(Ⅱ),Zn(Ⅱ)) are synthesized. The structure of complexes is two discrete Schiff base unit bridged. The complexes were condensed from series sub-stituent Ketones (5-chloro-2-hydroxybenzophenone, 5-methyl-2-hydroxy-benzophenone, 5-Bromo-2-hydroxybenzop- henone) and dialdehydes (5,5′-methylene-disalicylaldehyde) with the amino group of 1,2-diaminobenzene, and by Metal ion as template. The compounds were characterized by elemental analyses, FT-infrared spectra, Raman, ¹H NMR, UV-vis electronic spectra, EPR spectra. The FT-infrared spectra and Raman spectra of complexes were compared and discussed. The UV-vis election spectra, ¹H NMR and EPR spectra of complexes have also been attributed and minutely analyzed.     

Syntheses and Structures of Two New Cobalt Supramolecular Complexes, [Co(4,4'-bipy)_2(H_2O)_4]· [Co_2(4,4'-bipy)3O(H_2O)_8]·2TST·2(4,4'-bipy)·4H_2 and [Co(4,4'-bipy)_2(H_2O)_4]DSNT'4,4'-bipy

Two new cobalt(Ⅱ) supramolecular complexes [Co(4,4'-bipy)_2(H_2O) _4]·[Co_2(4,4'-bipy)3-(H_2O) _8]·2TST-2(4,4'-bipy)·4H_2O 1 and [Co(4,4'-bipy) _2(H_2O) _4]DSNT·4,4'-bipy 2 based upon the assembly of Co(Ⅱ), 4,4'-bipyridine (4,4'-bipy) and two new multifunctional organic ligands, 2,4,6-tris(4-sulfophenyl-amino)-1,3,5-triazine (H_3TST) and 2,4-bis(p-sulfanilato)-6-diethylamino-1,3,5-triazine (H_2DSNT), have been prepared by hydrothermal method and characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal structure of 1 is of monoclinic, space group P2_(1/n) with α= 13.599(4), b = 18.988(6), c = 22.995(7) A, β = 90.273(6)°, V= 5938(3) A~3, Z = 4, C_(56)H_(59)CO_(1.5)N_(13)O_(17)S_3, M_r = 1370.74, D_c = 1.533 g/cm~3,μ = 0.613 mm~(-1), F(000) = 2842, GOOF = 1.018, the final R = 0.0796 and wR = 0.1498 for 9019 observed reflections with I > 2o(I). The crystal structure of 2 belongs to the monoclinic system, space group C2/c with α = 18.864(6), b = 14.283(5), c = 20.246(7) A, β = 107.799(6)°, V = 5194(3) A~3, Z = 4, C_(49)H_(52)CoN_(12)O_(10)S_2, M_r = 1092.08, D_c = 1.397 g/cm~3, μ= 0.480 mm~(-1), F(000) = 2276, GOOF = 1.059, the final R = 0.0665 and wR = 0.1900 for 4887 observed reflections with I> 2σ(I). The results of X-ray crystal structure analysis revealed that complexes 1 and 2 exhibit layered supramolecular frameworks stabilized by electrostatic interactions, π-π interactions and hydrogen bonds.     

Synthesis, crystal structure and forming mechanism of two novel copper (Ⅱ) α-methacrylate complexes with benzimidazole

Two copper (Ⅱ) a-methacrylate complexes with benzimidazole, Cu [CH_2=C( CH_3)-COO]_2(C_7H_6N_2)_2(1) and Cu_2 [CH_2=C(CH_3)-COO]_4(C_7H_6N_2)_2 (2), have been prepared and characterized by elemental analyses, IR and electronic reflectance spectroscopies. The single crystal X-ray diffraction study of the two complexes shows that complex 1 has a square planar configuration, while complex 2 has a binuclear cage structure. The crystal structural analyses show that both complexes 1 and 2 are monoclinic, with space group P2_1/c, a=0.924 16(8) nm, b=1.233 02(13) nm, c =0.989 1(3) nm, β=91.912(13)°, D_c=1.386 g/cm~3, Z=2, R=0.033 9 for the former; and a=0.905 7(2) nm, b=2.252 1(5) nm, c=1.623 5(4) nm, β=90.11(2)°, D_c =1.411 g/cm~3 , Z=4, R=0.056 8, Cu-Cu=0.266 21 nm for the latter. Different structural types of complexes 1 and 2 were produced simultaneously in the reaction of copper (Ⅱ) α-methacrylate with benzimidazole in methanol solution. The forming mechanism of the complexes has been summarized.     

Crystal Structure and Inhibitory Activity against Xanthine Oxidase of Bis(μ2-chloro)-chloro-(μ-N,N'-(2-pyridylmethylene)Furanmethanoamine Copper(Ⅱ)Complex

A chloro-bridged dinuclear copper(Ⅱ) complex with ligand 2-pyridylme-thylene-furfurylamine has been synthesized and characterized by single-crystal X-ray diffraction,and its inhibitory activity on xanthine oxidase(XO)Was also evaluated.It crystallizes in the triclinic system,space group P-1 with a=8.0441(16),b=8.5663(17),c=10.060(2)(A),α=77.52(3),β=72.04(3),γ=70.12(3)°,V=615.3(2)(A)3,Z=1,Dc=1.731 g/cm3,F(000)=322,the final R=0.0401 and wR=0.0934 for 1971 observed reflections with Ⅰ＞2σ(Ⅰ).X-ray analysis reveals that the Cu(Ⅱ)cation is five-coordinated by two N atoms of Schiff base and three C1 anions.The C-H…Cl intermolecular and intramolecular hydrogen bonds connect the molecules to form a three-dimensional network.Tilis copper(Ⅱ) complex shows more potent inhibitory activity against XO with Ⅰ C50=3.48/μM than the standard inhibitor allopurinol.     

Polymerization of lactic <Emphasis Type="Italic">O</Emphasis>-carboxylic anhydride using organometallic catalysts

The ring-opening polymerization of 5-methyl-1,3-dioxolane-2,4-dione(lactic O-carboxylic anhydride,LacOCA) using organometallic complexes,including Co(Ⅲ) complexes with Schiff base ligands,Tin(Ⅱ) alphatates and Al(Ⅲ) complexes with Schiff base ligands,was explored.The polymerization was carried out by treatment of the organometallic complexes with LacOCA in toluene under mild conditions.The corresponding poly(lactic acid) was characterized by spectroscopy and thermal analyses,which revealed insight into the structure of the effective catalyst for the polymerization of LacOCA.     

Synthesis of Mg5(CO3)4(OH)2·4H2O with Flower-like Microstructure and Its Catalytic Activity for Transesterification of Dimethyl Carbonate with Phenol

A novel flower-like hydrated magnesium carbonate hydroxide,Mg_5(CO_3)_4(OH)_2·4H_2O,with micro-structure composed of individual thin nano-sheets was synthesized using a facile solution route without the use of template or organic surfactant.Reaction time has an important effect on the final morphology of the product.The micro-structure and morphology of Mg_5(CO_3)_4(OH)_2·4H_2O were characterized by means of X-ray diffractometry(XRD),field-emission scanning electron microscopy(FE-SEM).Brunauer-Emmett-Teller(BET)surface areas of the samples were also measured.The probable formation mechanism of flower-like micro-structure was discussed.It was found that Mg_5(CO_3)_4(OH)_2·4H_2O with flower-like micro-structure was a novel and efficient catalyst for the synthesis of diphenyl carbonate(DPC)by transesterification of dimethyl carbonate(DMC)with phenol.     

COMPLEXES OF RARE EARTH NITRATE WITH SCHIFF BASE DERIVED FROM VANILLIN AND P-TOLUIDINE

In this paper,complexes of rare earth nitrate with Schiffbase derived from vanillin(3-methoxy-4-hydroxy-benzaldehyde)andp-toluidine[LnL_2(NO_3)_2]NO_3(Ln=La-Eu except Pm,L=Schiff base ligand)have been prepared and characterized.     

Synthesis,structural characterization and antibacterial activity of diorganotin(Ⅳ) complexes with ONO tridentate Schiff bases containing pyridine ring

Five organotin（IV） complexes,were obtained by reaction of SnR₂Cl₂（R = Ph,Me,Bu） with ONO donor Schiff bases.The synthesized complexes have been investigated by elemental analysis and IR,¹H NMR,and ¹¹⁹Sn NMR spectroscopy.These data show that the Schiff base acts as a tridentate dianionic ligand and coordinates via the imine nitrogen and two oxygen atoms.The Xray crystallography of complex 4 shows a dimeric structure for this molecule.The in vitro antibacterial activities of the Schiff bases and their complexes have been evaluated against Gram-positive（Bacillus subtilis and Staphylococcus aureus） and Gram-negative （Escherichia coli and Pseudomonas aeruginosa） bacteria and compared with the standard antibacterial drugs.     

Synthesis,structures and magnetic properties of a series of polynuclear copper(Ⅱ)-lanthanide(Ⅲ) complexes assembled with carboxylate and hydroxide ligands

Heterometallic copper(Ⅱ)-lanthanide(Ⅲ) complexes have been made with a variety of exclusively O-donor ligands including betaines (zwitterionic carboxylates) and chloroac-etate,which are dinuclear CuLn,tetranuclear Cu2Ln2,pen-tanuclear Cu2Ln2,and octadecanuclear Cu12Ln6 complexes.Hie results show that subtle changes in both the carboxylates and acidity of the reaction solution can cause drastic changes in the structures of the products.Magnetic studies exhibit that shielding of the Ln3 4f electrons by the outer shell electrons is very effective to preclude significant coupling interaction between the Ln3 4f electrons and Cu2 3d electrons in either a mono-atomic hydroxide-bridged,or a carboxylate-bridged system.     

Synthesis, Crystal Structure and Electrochemistry Properties of a (N,N'-Ethylene-bis(salicylaldiminato)) Nickel(Ⅱ) Complex, [Ni2(salen)2]·NCS-NH4

A new Ni(Ⅱ) complex [Ni2(salen)2]·(NCS)·NH4 (salen = N,N'-bis(salicylidenea-mino)ethanato) has been prepared and structurally characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. It crystallizes in the orthorhombic system, space group Pbca with a = 16.8725(13), b = 19.0046(15), c = 20.0583(16) (A), Z = 8, V = 6431.8(9) (A)3, C33H32N6Ni2O4S1, Mr= 726.13, Dc = 1.500 g/cm3, F(000) = 3008, μ = 1.284 mm-1, the final R = 0.0394 and wR = 0.0767 for 4449 observed reflections with Ⅰ＞2σ(Ⅰ). The complex involves a N,N'-ethylene-bis(salicylaldiminato) Schiff base, an isothiocyanato anion and an ammonium cation. The nickle(Ⅱ) ion adopts a distorted square coordination geometry with N2O2 set of Schiff base ligand. The complexes are linked into a dimmer via intermolecular hydrogen bonds and the [Ni(salen)] moieties are connected together to form a 2-D layer structure by intermolecular N-H…O hydrogen bonds and π-π stacking. Cyclic-voltammetry method was used to characterize electrochemically the complex.     

SYNTHESIS AND MAGNETIC PROPERTY OF CARBOXYL BRIDGING DICOPPER(Ⅱ) COMPLEXES

Two new dicopper(Ⅱ) complexes with two carboxyl bridgings in one molecule[Cu(dm-phen)(HCOO)]_2(NO_3)_2 3H_2O(1). [Cu(ds-phen)(CH_3COO)]_2 (NO_3)_2 3H_2O(2). one dicopper(Ⅱ) complex with one carboxyl bridging and one hydroxo bridging in one molecule [Cu_2(OH)(C_2H_5COO)(ds-phen)_2]. (NO_3)_2 H_2O(3) and one cononuclear Cu(Ⅱ) complex [Cu(de-phen)(CF_3COO)](NO_3).H_2O(4)(dm-phen= 2,9-dimethyl-1,10-phenanthrolin)were prepared and characterized. The effective magnetic moment, u elf, was measured and their magnetic properties were discussed. The coordination modes of carboxyl moieties in all the title complexes were proposed.     

Synthesis,Crystal Structures,DNA Cleavage and DNA-binding Studies of Ho(Ⅲ) and Er(Ⅲ)Complexes Based on Macrocyclic Schiff Base

Two novel macrocyclic Schiff base complexes [LnL(PhCOO)(CH_3OH)](ClO_4)_2·(CH_3OH)_2(Ln =Ho, 1; Ln = Er, 2), in which L denotes the macrocyclic ligand, were synthesized via condensation of 2,6-diformyl-4-methyl-phenol and 1,3-diamino-2-propanol by employing benzoate as the second ligand. Their crystal structures were determined by X-ray diffraction, which showed that both complexes belong to a monoclinic system with space group P2_(1/c). The coordination polyhedron displayed a distorted bicapped trigonal prism with the coordination number of eight. Both complexes efficiently cleaved supercoiled DNA to its nicked circular form. The UV-vis absorption results and ethidium bromide(EB) fluorescence spectra indicated that the complexes bind to CT-DNA in an intercalative mode, with K_(sq) values to be 11830 and 10560, respectively.     

Rare earth complexes with noncyclic polyether-methionine Schiff base

A novel Schiff base (TAMET) was synthesized by the condensation of tetraglycol aldehyde with methionine and a mild oxidant CrO3· (C5H5N)2 was selected for the reaction. Seven new rare earth complexes with this Schiff base have been synthesized and characterized by elemental analysis, TG-DTA, molar conductivity, magnetic susceptibility and IR, especially 1H NMR spectra. Information was obtained from reflectance spectra and the coordination of sulfur atom to rare earths was discussed. The experimental results show that thesecompounds have some biological activity and could dispose of O2.     

Synthesis,characterization and magnetism of copper(Ⅱ)-lan-thanide(Ⅲ) heterobimetalic complexes with N,N'-oxamidobis-(benzoato) cuprate (Ⅱ)

Seven new μ-oxamido copper(Ⅱ)-lanthanide(Ⅲ)hetero-bitnetalic complexes described by the fonnula Cu(obbz)Ln-(Ph-phen)2NO3(Ln=La,Nd,Eu,Gd,Tb,Ho,Er),where obbz denotes the oxamidobis(benzoato)and Ph-phen represents 5-phenyl-1,10-phenanthroline,have been synthesized and characterized by the elemental analyses,spectro-scopic(IR,UV,ESR)studies,magnetic moments(at room temperature)and molar conductivity measurement.The temperature dependence of the magnetic susceptibility of Cu(obbz)Gd(Ph-phen)2NO3 complex has been measured over the range 4.2-300 K.The least-squares fit of the experimental susceptibilities based on the spin Hamiltonian operator,H=-2JS1 S2,yielded J= 1.28 cm-1,a weak ferromagnetic coupling.A plausible mechanism for a ferromagnetic coupling between Gd(Ⅲ)-Cu(Ⅱ)is discussed in terms of spin-polarization.     

Synthesis,spectral studies,thermal behavior,and antibacterial activity of Ni(Ⅱ),Cu(Ⅱ),and Zn(Ⅱ) complexes with an ONO tridentate Schiff base

Three new transition metal complexes have been synthesized with a Schiff base,3-(2-hydroxy-5-chlorophenylimino)-l,3- diphenylpropen-1-one.In all complexes Schiff base is completely deprotonated and coordinated to metal as tridentate ligand via phenolic and enolic oxygens and imine nitrogen.Thermal decomposition of the complexes has been studied by thermogravimetry. The in vitro antibacterial activity of Schiff bases and their complexes has been evaluated and compared with the standard drugs.