Synthesis, characterization and magnetism of binuclear cobalt (II) complexes bridged by tetracarboxylato groups

Three new binudear cobalt (II) complexes with extended te-tracarboxylato- bridge have been synthesized and characterized, namely [Co2 (PMTA) (bpy)4] (1), [Co2(PMTA)-(phen)4] (2) and [Co2(PMTA) (NO2phen)4] (3), where PMTA represents the tetraanion of pyroniellitic acid, and bpy, phen, NO2-phen denote 2,2'-bipyridine, 1,10-phenan-throline; 5-nirto-1, 10-plienanthroline, respectively. Based on elemental analyses, molar conductivity measurements, IR and electronic spectra studies, it is proposed that these complexes have PMTA-bridged structures and consist of two cobalt (II) ions, each in a distorted octahedral environment. These complexes were further characterized by variable temperature magnetic susceptibility measurements (4-300 K) and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, giving the exchange integral J = - 1.02 cm-1 for 1, J = -1.21 cm-1 for 2 and J = - 1.18 cm-1 for 3, respectively. These results revealed the operation of antiferromagneti     

Synthesis,crystal structures and anticancer activities of two decavanadate compounds

Two ammonium decavanadate(V) compounds, (H₂tmen)₃V₁₀O₂₈·6H₂O (1) and (H₂en)₃V₁₀O₂₈·2H₂O (2), where H₂tmen and H₂en represent the doubly protonated N,N,N′,N′-tetramethylethylenediammonium ion and doubly protonated ethylenediammonium ion, respectively, have been synthesized and structurally characterized by elemental analyses, spectroscopic (i.r., e.s.r.) studies, and single-crystal X-ray diffraction. Both crystal structures reveal the presence of the [V₁₀O₂₈]⁶⁻ cluster anions, doubly protonated diammonium cations, and lattice water molecules. Hydrogen bonds assemble these two compounds to form three-dimensional networks. The in vitro anticancer activity against A549 and P388 tumor cells lines has also been determined by the MTT-based assay, and the results suggest that both compounds can inhibit proliferation of these two kinds of tumor cells.     

相转移催化应用于催化裂化汽油氧化脱硫的研究

随着人们环境保护意识的增强及原油硫含量的增大, 生产满足环境保护要求的清洁燃料是全球炼油工业的发展趋势, 燃料油脱硫显得越来越重要. 在众多的脱硫方法中, 选择性氧化脱硫技术以其工艺条件温和, 脱硫效果明显等特点, 受到了炼油行业的极大关注[1~3], 但脱硫率偏低(30％), 其关键是水相氧化剂与含硫化合物的有效混合. 本文将相转移催化应用于催化裂化(FCC)汽油的氧化脱硫中, 并对脱硫的工艺和机理进行了研究.     

Synthesis, crystal structure, cytotoxicities and DNA-binding properties of a tetracopper(II) complex with N-benzoato-N′-[2-(2-hydroxyethylamino)ethyl-amino]oxamide ligand

A new dissymmetrical N,N??-bis(substituted)oxamide ligand, N-benzoato-N??-[2-(2- hydroxyethylamino)ethyl]oxamide (H₃bhyox), and its tetranuclear copper(II) complex, [Cu₄(bhyox)₂(dabt)₂](ClO₄)₂ (1) have been synthesized and characterized (dabt?=?2,2??-diamino- 4,4??-bithiazole). The crystal structures of H₃bhyox and complex 1 have been determined by X-ray single-crystal diffraction. Complex 1 has a cyclic tetranuclear cation with an embedded inversion center, in which the Cu?CCu separations through the oxamido and carboxyl bridges are 5.2246(6) and 5.3141(6) ?, respectively. Both Cu(II) centers at the inner and outer sites of the cis-bhyox^3? ligand have square pyramidal geometries. There is a 3D hydrogen-bonding network in the crystal. The cytotoxicities and DNA-binding properties of H₃bhyox and complex 1 were studied. Both compounds can interact with HS?CDNA by intercalation, and the DNA-binding affinities are consistent with their in vitro cytotoxicities.     

Synthesis, characterization and magnetic properties of novel μ-isophthalato oxovanadium(IV) binuclear complexes

Four novel oxovanadium(IV) binuclear complexes have been synthesized, namely [(VO)₂(IPHTA) (L)₂SO₄ (L denotes 2,2′-bipyridine (bpy); 1,10-phenanthroline (phen); 4,4′-dimethyl-2,2′-bipyridine (Me₂bpy) and 5-nitro-1,10-phenanthroline (NO₂-phen)), where IPHTA is the isophthalate dianon. Based on elemental analyses, molar conductivity measurements, IR and electronic spectra studies, it is proposed that these complexes have IPHTA-bridged structures and consist of two vanadium(IV) atoms in a square-pyramidal environment. The complexes [(VO)₂(IPHTA)(Me₂bpy)₂]SO₄ (1) and [(VO)₂(IPHTA)(bpy)₂]SO₄ (2) were characterized by variable temperature magnetic susceptibility (4–300 K) and the data could be well fitted by the least-squares method to a susceptibility equation derived from the spin Hamiltonian operator, . The exchange integral, J, was found to be −26.8 cm⁻¹ for (1) and −31.0 cm⁻¹ for (2). These results are commensurate with antifferomagnetic interactions between two oxovanadium(IV) ions within each molecule. The influence of different terminal ligands on magnetic interactions between the metals of this kind of complexes is also discussed.     

Synthesis,structure and DNA-binding studies of tetranuclear copper(II) complexes bridged by asymmetrical<Emphasis Type="Italic"> N</Emphasis>,<Emphasis Type="Italic">N′</Emphasis>-bis(substituted)oxamides

Two tetranuclear copper(II) complexes bridged by asymmetrical N,N′-bis(substituted)oxamides have been synthesized and characterized as [Cu₄(dmapob)₂(Me₂bpy)₂](pic)₂·6H₂O (1) and [Cu₄(oxbe)₂(dabt)₂](pic)₂ (2), where H₃dmapob and H₃oxbe denote N-benzoato-N′-[3-(dimethylamino)propyl]oxamido and N-benzoato-N′-(2-aminoethyl)oxamide, respectively; and Me₂bpy, dabt, and pic represent 4,4′-dimethyl-2,2′-bipyridine 2,2′-diamino-4,4′-bithiazole, and 2,4,6-trinitrophenol, respectively. Complex 1 was characterized by elemental analyses, IR and electronic spectra, and single-crystal X-ray diffraction. Its structure consists of two asymmetrical binuclear copper(II) units linked by carboxyl bridges into a circular tetranuclear copper(II) complex with an embedded center of inversion. The copper(II) centers are in square-planar and distorted square-pyramidal environments. Hydrogen bonds and aromatic stacking interactions link the tetranuclear copper(II) fragments into a 3D supramolecular structure. The interactions of complexes 1 and 2 with herring sperm DNA (HS-DNA) were investigated by electronic and fluorescence spectra and viscosity measurements. Both complexes bind to HS-DNA via the intercalative mode, and complex 2 displays a significant binding propensity to HS-DNA.     

Synthesis,spectral and ferromagnetic interactions in isophthalato bridged binuclear copper(II) complexes

Transition Metal Chemistry - Four novel copper(II) binuclear complexes have been synthesized and characterized, namely [Cu2(IPHTA)( L)2](ClO4)2 (L denotes 2,2′-bipyridine (bpy); 1,10-...     

Synthesis and characterization of μ-oxamido copper(Ⅱ)-iron(Ⅱ) heterobinuclear complexes with an antiferromagnetic exchange interaction

Four new u-oxamido heterobinuclear complexes have been synthesized and identified as [Cu(oxap)Fe(L)2]SO4, where oxap denotes the N, N'-bis(2-aminopropyl)oxamido dianion and L represents diaminoethane (en); 1,3-diaminopropane (pn); 1,2-diaminopropane (ap) and 2,9-dimethyl-1,10-phenanthroline (Me2-phen). Based on the elemental analyses, spectroscopic studies, magnetic moments (at room temperature) and molar conductivity measurements, extended oxamido-bridged structures consisting of a copper(Ⅱ) and an iron(Ⅱ) ions, which have a square planar environment and an octahedral environment, respectively, are proposed for these complexes. Complexes [Cu(oxap)Fe(en)2]SO4 (1) and [Cu(oxap)Fe(pn)2]SO4 (2) have been characterized by variable temperature magnetic susceptibility (4.2~300 K) and the observed data were least-squares fitted to the susceptibility equation derived from the spin Hamiltonian including single-ion zero-field interaction for the iron(Ⅱ) ion, H=-2JS1.S2-DSzl2, giving the exchange integrals J=-2     

Synthesis, characterization and magnetic properties of μ-iodanilato dinuclear oxovanadium (Ⅳ) complexes

Five oxovanadium(Ⅳ) dinuclear complexes described by the overall formula [(VO)2(IA)L2]-SO4, where IA represents the dianion of iodanilic acid and L denotes 2,2'-bipyridine (bpy) ; 4,4'-dimethyl-2,2'-bipyridine (Me2-bpy); 1,10-phenanthroline (phen); 4,7-diphenyl-1, 10-phenanthroline (Ph2-phen) and 5-nitro-l, 10-phenanthroline (NO2-phen) , have been synthesized and characterized by elemental analyses, molar conductivity and room-temperature magnetic moment measurements, IR and electronic spectral studies. It is proposed that these complexes have IA-bridged structures and consist of two oxovanadium(Ⅳ) ions each in a square- pyramidal environment. The complexes [ ( VO)2 (IA) (bpy )2 ] SO4 (1) and [ ( VO )2 ( IA) ( phen)2 ] -SO4 (2) were further characterized by variable temperature (4.2-300 K) magnetic susceptibility measurements and the observed data were fitted to the modified Bleaney-Bowers equation by the least-squares method, giving the exchange integral J = -2.15 cm-1 for 1 and J = - 9.88 cm-1 for 2     

Synthesis and magnetism of μ-isophthalato dinuclear lanthanide(Ⅲ) complexes

Seven new μ-isophthalato dinuclear lanthanide(Ⅲ) complexes, namely [Ln2(IPHTA)(Me2-phen)4-(ClO4)2](ClO4)2 (Ln = La, Nd, Sm, Eu, Gd, Ho, Er), where Me2-phen denotes 2,9-dimethyl-1, 10-phenanthroline (Me2-phen) , IPHTA represents isophthalate dianion, have been synthesized and characterized by elemental analyses, molar conductance measurements, IR, ESR and electronic spectra. The variable-temperature magnetic susceptibilities of [Gd2( IPHTA) (Mez-phen)4 (ClO4)2] (ClO4)2 complex were measured in the temperature range of 4-300 K and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, H = - 2JS1 · S2, giving the exchange parameter J =- 0.19 cm-1 . This result is commensurate with a weak antiferromagnetic spin-exchange interaction between Gd(Ⅲ)-Gd(Ⅲ) ions within the complex.