首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
A new mononuclear tetracyanometallic complex, (n-Bu4N)[(dbphen)Fe(CN)4] (1, dbphen = 5,6-dibromo-1,10-phenanthroline), has been prepared by reacting [(dbphen)FeII(py)2(SCN)2] and KCN in water and further oxidized with chlorine. With the use of 1 as building block, two trinuclear Fe2M complexes, [(dbphen)2Fe2(CN)8Cu(Me3tacn)]·3H2O (2), [(dbphen)2Fe2(CN)8Ni(dabhctd)]·2H2O (3) and a chain complex of squares [(dbphen)2Fe2(CN)8Co(MeOH)2]n (4), have been synthesized and structurally characterized. Magnetic studies show ferromagnetic coupling between FeIII and MII (M = Cu, 2; Ni, 3) ions bridged by cyanides in complexes 2 and 3, while complex 4 exhibits meta-magnetic behavior.  相似文献   

2.
Two new binuclear radical complexes derived from a new long nitronyl nitroxide ligand, 2-[4-(5-pyrimidyl)phenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (4-NITPhPyrim), and M(hfac)2 (M2+ = Cu2+, Mn2+; hfac = hexafluoroacetylacetonato), [Cu(hfac)2(4-NITPhPyrim)]2 · 4H2O (1) and [Mn(hfac)2(4-NITPhPyrim)]2 · 4H2O (2), were synthesized as well as characterized structurally and magnetically. X-ray analysis indicates that 1 and 2 are rectangle-like centrosymmetric dimer M2L2 complexes. Magnetic measurements indicate that there are two types of magnetic exchanges in 1: the ferromagnetic (FM) exchange between the Cu(II) ion and the directly bonded nitroxide unit (J1 = 24.20 cm−1) and the weak FM exchange of Cu-NIT through the pyrimidine and phenyl rings (J2 = 0.62 cm−1). Besides the strong antiferromagnetic (AFM) coupling between the Mn(II) ion and the directly bonded nitroxide unit (J = −87.61 cm−1), there is a weak FM interaction between the two Mn-NIT pairs (θ = 0.39 K) in 2.  相似文献   

3.
A dissymmetrical double Schiff base Cu(II) mononuclear complex: CuHL (1) (where H3L is N-3-carboxylsalicylidene-N-salicylaldehyde-1,2-diaminoethane) and two trinuclear complexes: [CuL(H2O)CoCuL] · H2O · CH3OH (2) and [(CuL)2Ni] · 2H2O (3) have been synthesized and characterized by means of elemental analyses, IR and electronic spectra. The crystal structures of two heterotrinucler complexes were determined by X-ray analysis. Each dissymmetrical cell unit of the complex 2 contains two heterotrinucler neutral molecules. In each neutral molecule, the central Co2+ ion is located at the site of O6 with a distorted octahedral geometry and one terminal Cu2+ ion at the four-coordination site of N2O2, but the other one at the square-pyramidal environment of N2O3. Each dissymmetrical unit of the complex 3 contains a heterotrinucler neutral molecule, whose structure is similar to that of 2 except two terminal Cu2+ ions both at the inner site of N2O2. The magnetic properties of two heterotrinucler complexes have been determined in the temperature range of 5-300 K, which indicate that the interaction between the central Co2+ ion or Ni2+ ion and the outer Cu2+ ions is antiferromagnetic. The exchange integrals are equal to −26.2 cm−1 for 2 and −50.6 cm−1 for 3.  相似文献   

4.
The reactions of metal(II) chlorides and bromides with 8-methylquinoline (8-mequin) in neutral and acidic solutions were investigated. The reaction with ZnCl2, ZnBr2, CoCl2, CoBr2, CuCl2 or CuBr2 with the appropriate HX in water or aqueous ethanol gave complexes of the formula (8-mequin)2MX4 (1, M = Cu, X = Cl; 2, M = Cu, X = Br; 3, M = Co, X = Cl; 4, M = Co, X = Br) or (8-mequin)2ZnX4·nH2O (5, X = Cl, n = 0; 6, X = Br, n = 0; 7, X = Cl, n = 1; 8, X = Br, n = 1). Crystals of 1, 2 and 4-8 suitable for single crystal X-ray diffraction were obtained and the structures reported. Compounds 1 and 2 crystallize in the monoclinic space group C2/c, while 4-8 crystallize in the triclinic space group, . Variable temperature magnetic susceptibility data indicate very weak interactions for the copper compounds 1 and 2, while the magnetic behavior of 3 and 4 is dominated by single ion anisotropy, with weaker antiferromagnetic interactions.  相似文献   

5.
A new dinuclear manganese(II)-azido complex: [Mn(2,2′-dpa)(N3)2]21 (2,2′-dpa = 2,2′-dipicolylamine) has been synthesized solvothermally. X-ray crystallography analysis reveals that it consists of two crystallographically independent dimeric manganese moieties; each manganese(II) atom is coordinated by one 2,2′-dipicolylamine, one terminal azido ligand, and double end-on bridging azido ligands, exhibiting a slightly distorted octahedral sphere. There are extensive short contacts among dimeric manganese moieties, which extend the structure into an interesting three-dimensional supramolecular array. Magnetic determination of 1 indicates that dominant ferromagnetic interaction and weak antiferromagnetic interaction, which are ascribed to the end-on azido bridges and the short contacts, respectively, co-exist in this complex.  相似文献   

6.
The synthesis, magnetic properties and single crystal study of a new spin crossover compound [Fe(EPPA)(bpym)](ClO4)2 with EPPA = N-(2-aminoethyl)-N-(3-aminopropyl)-2-(aminomethyl)pyridine, bpym = 2,2′-bipyrimidine are reported. Variable-temperature magnetic susceptibility data collected in the temperature range 10-294 K reveal the occurrence of a relatively cooperative spin transition with T1/2 = 108 K. The crystal structure of [Fe(EPPA)(bpym)](ClO4)2 was determined by single-crystal X-ray diffraction method. The structure of the complex consists of mononuclear [Fe(EPPA)(bpym)](ClO4)2 units. The potentially bis-bidentate bpym ligand acting as a bidentate one, is coordinated to iron(II) in cis-position by two nitrogen atoms. The four remaining positions in the pseudooctahedral [FeN6] core are occupied by one pyridinic and three aliphatic nitrogens of the EPPA ligand. The network of cooperative links in the crystal lattice is represented by H-bonding and π stacking interactions.  相似文献   

7.
Four lanthanide coordination polymers formulated as {[La3L9(H2O)3]EtOH · H2O}n1, {[Pr2L6(H2O)2]HL · H2O}n2, {[Dy2L6(H2O)]0.5HL · H2O}n3 and {[Ho2L6(H2O)]0.5HL · H2O}n4 and HL = trans-2-butenoic acid have been synthesized from the corresponding pure lanthanide oxide and HL acid in water at pH 3. The compounds were characterized by chemical analysis, IR spectroscopy, thermogravimetry, variable-temperature magnetic susceptibility and single crystal X-ray diffraction studies. A common feature in these materials is the presence of two differentiated lanthanide nodes linked by carboxylates into extended chains. These are further connected by inter- and intra-molecular hydrogen-bonds involving ligand and solvate molecules. Weak ferromagnetic interactions appear to be operative in the Dy material.  相似文献   

8.
Compounds FeIII(3-CH3O-qsal)2PF6 · nH2O (n = 0, 2) (1, 1 · 2H2O) were synthesized and characterized: the structure of 1 and the magnetic properties of both compounds were determined. Compound 1 · 2H2O presents properties characteristic of high-spin Fe(III), while 1 presents properties of low-spin Fe(III) with an onset of a gradual spin crossover at ca. 300 K.  相似文献   

9.
A series of heterobimetallic polymeric complexes of manganese, cobalt, zinc, cadmium and nickel, [M(Mo2O5L2)(MeOH)2(H2O)2]n·nH2O {M = Mn (2), n = 1, Co (3), n = 0, Zn (4), n = 1 and Cd (5), n = 1} and [Ni(Mo2O5L2)(MeOH)(H2O)3]n·2H2O·MeOH (6) have been synthesized form the reaction of [{Na4(H2O)4(μ-H2O)2} ⊂ (Mo2O5L2)2] (1) {LH2 = 2-(3,5-di-tert-butyl-2-hydroxybenzylamino)acetic acid} with the corresponding metal salts. The complexes have been structurally characterized. The Complexes, 3 and 6 undergo thermal decomposition to afford mixed oxides of the type, MMoO4·MoO3 {M = Co or Ni}.  相似文献   

10.
Two new inorganic-organic hybrid materials - [{M(C5H5N)4}2]V4O12 (M = Cu, 1; M = Co, 2) have been synthesized and characterized by spectroscopic methods, X-ray powder diffraction, thermogravimetry, magnetometry and complete single crystal structure analysis. The structures of 1-2 are comprised of layers containing centrosymmetric {V4O12} rings connected to {M(C5H5N)4} units by V-O-M bridges (M = Cu, 1; M = Co, 2). The layers are parallel to the (1 0 1) crystal planes and there are pyridine stacking interactions between layers. The effective magnetic moment, μeff, values for 1 and 2 are 1.9 μB and 3.9 μB, respectively, indicating some orbital contributions in each case. Both compounds exhibit Curie-Weiss magnetic behavior over the entire range above the critical temperature.  相似文献   

11.
Two oxamido-bridged trinuclear complexes of formula {[(LCu)(EtOH)]2Mn(EtOH)2}(ClO4)2 (1) and {[(LCu)(EtOH)]2Co(EtOH)2}(ClO4)2 · 2H2O (2) (H2L = 2,3-dioxo-5,6:13,14-dichlorobenzo-7,12-diphenyl-1,4,8,11-tetraazacyclo-pentadeca-7,11-diene) have been synthesized and structurally characterized. The central ions of complexes 1-2 (Mn(II), Co(II)) are all bridged by macrocyclic oxamido groups. Their magnetic properties were studied by susceptibility versus temperature measurement, the best fitting of the experimental data led to J = −16.91 cm−1 for 1 and J = −27.73 cm−1 for 2.  相似文献   

12.
The first crystal and molecular structure of a transition metal complex containing 1,2-dithiocroconate (1,2-dtcr, dianion of 1,2-dimercaptocylopent-1-ene-3,4,5-trione), [Cu(bpca)(H2O)]2[Cu(1,2-dtcr)2]·2H2O (where bpca is the bis(2-pyrdidylcarbonyl)amide anion), has been determined by single crystal X-ray diffraction methods. The compound crystallizesin the monoclinic syste, space group P21/c, with a = 11.661(3), b = 20.255(6), c = 8.265(3) Å, ß = 107.26(2)° and Z = 2. The structure is formally built of [Cu(1,2-dtcr)2]2− and [Cu(bpca)(H2O)]+ ions and water of hydration. The copper atom of the anion is situated at a crystallographic inversion centre, bonded to four sulfur atoms in a planar, approximately square arrangement. In the cation the copper equatorial plane is formed by the three nitrogen atoms of the bpca ligand and a water oxygen atom. In addition there is a very weak axial bond to one of the sulfur atoms of a 1,2-dtcr ligand in the anion. Through these latter weak bonds each anion is connected to, and sandwiched between, two cations, resulting in neutral, trinuclear, centrosymmetric formula units. The triple-decker molecules are arranged in stacks along the crystallographic a-axis creating close contacts between the terminal copper atoms and bpca groups of the neighbouring molecules. This intermolecular interaction is, however, too weak to define the structure as a chain compound. The distance between adjacent copper atoms within the trinuclear unit is 4.189(1) Å, while the shortest intra-stack metal-metal separation between terminal copper atoms is 5.281(1) Å. Variable-temperature magnetic susceptibility measurements in the temperature r.2–140 K reveal that a Curie law is followed; with three non-interacting copper(II) ions in the formula unit.  相似文献   

13.
Mono- and di-manganese inclusion compounds 1 and 2 are reported. Two mono-manganese molecules Mn(bpy)2(NO3)2 (bpy=2,2′-bipyridine) and [Mn(bpy)2(NO3)(H2O)]·NO3 coexist in the mole ratio of 1:1 in the structure of 1, while two di-manganese molecules [Mn2O(bpy)2(phtha)2(H2O)2]·(NO3)2 (phtha=phthalate) and [Mn2O(bpy)2(phtha)2(NO3)(H2O)]·NO3 in the structure of 2. Refluxing Mn(NO3)2/bpy/phthalic acid reaction mixtures in CH3CN leads to the isolation of 1, further concentration of the reaction solution in raising temperature results in 2. The Mn1 and Mn2 units in the inclusion compounds 1 and 2 are similar to other reported Mn1 and Mn2 analogs, respectively. The Jahn–Teller distortion was observed to give rise to the elongation along the Oterminal---Mn---Ocarboxyl axes for all the four Mn(III) sites in 2, leading to unexpected longer Mn(III)---Oaqua than Mn(II)---Oaqua in 1. Extensive hydrogen bonding interactions among H2O, NO3 − and COOH were observed in the two inclusion compounds. Cyclic voltammetry of 2 in DMF displays two quasi-reversible redox couples at +0.10/+0.22 and −0.43/−0.36 V assigned to the Mn(III)Mn(IV)/2Mn(III) and 2Mn(III)/Mn(III)Mn(II), respectively. Variable temperature magnetic susceptibilities of 1 and 2 were measured. The data were fit to a model including axial zero-field splitting term and a good fit was found with D=1.77 cm−1, g=1.98 and F=1.48×10−5 for 1. For 2, the least-squares fitting of the experimental data led to J=2.37 cm−1, g=2.02 and D=0.75 cm−1 with R=1.45×10−3.  相似文献   

14.
Six new transition metal complexes (M = Cu(II), Ni(II) and Mn(III)) of tridentate (H2L1, HL2) and/or bidentate (HL3, HL4) Schiff-base ligands, obtained from the condensation of salicylaldehyde with glycine, N-(2-aminoethyl)morpholine, 4-(2-aminoethyl)phenylic acid and 4-(2-aminoethyl)benzsulfamide, respectively, were synthesized and structurally determined by single-crystal X-ray analysis. Complexes 1-6 were evaluated for their effect on the jack bean urease and xanthine oxidase (XO). Copper(II) complexes 1-3 (IC50 = 0.43-2.25 μM) showed potent inhibitory activity against jack bean urease, comparable with acetohydroxamicacid (IC50 = 42.12 μM), which is a positive reference. And these copper(II) complexes (IC50 = 10.26-15.82 μM) also exhibited strong ability to inhibit activity of XO, comparable to allopurinol (IC50 = 10.37 μM), which was used as a positive reference. Nickel(II) and manganese(III) complexes 4-6 showed weak inhibitory activity to jack bean urease (IC50 = 4.36-8.25 μM) and no ability to inhibit XO (IC50 > 100 μM).  相似文献   

15.
Three novel hexa-transition-metal complexes substituted tungstoarsenates, [Ni6(imi)6(B-α-H3AsW9O33)2]·2H2O (1), [Zn6(imi)6(B-α-H3AsW9O33)2]·2H2O (2) and [Mn6(imi)6(B-α-H3AsW9O33)2]·4H2O (3) (imi = imidazole), have been synthesized hydrothermally without using any polyoxoanion as precursor and characterized by elemental analyses, IR, TG and X-ray single-crystal diffraction. Compounds 1-3 are isostructural, composed of [B-α-H3AsW9O33]12− anions and [M6(imi)6]12+ complex cations (M = Ni, Zn and Mn), all M atoms are square pyramidal geometry, and held together to form hexagonal metallocycles by edge-sharing oxygen atoms. In compounds 2 and 3, [M6(imi)6(B-α-AsW9O33)2] (M = Zn, Mn) segments act as 12-connected nodes to form complicated 3D network via hydrogen-bonding interactions, respectively. Magnetic measurements for 1 show the presence of ferromagnetic interactions within the hexanuclear Ni2+ cations.  相似文献   

16.
Using an anionic precursor [(Tp)FeIII(CN)3] (1) as a building block, two cyano-bridged centrosymmetric heterotrinuclear complexes, (2) and (3) (en = ethylenediamine), have been synthesized and structurally characterized. In each complex, [TpFe(CN)3] acts as a monodentate ligand toward a central [Mn(C2H5OH)4]2+ or [Ni(en)2]2+ core through one of its three cyanide groups, the other two cyanides remaining terminal. The intramolecular Fe-Mn and Fe-Ni distances are 5.2354(4) and 5.0669(11) Å, respectively. The magnetic properties of complexes 2 and 3 have been investigated in the temperature range of 2.0-300 K. A weak antiferromagnetic interaction between the Mn(II) and Fe(III) ions has been found in complex 2. The magnetic data of 2 can be fitted with the isotropic Hamiltonian: where J and J′ are the intramolecular exchange coupling parameters between adjacent and peripheral spin carriers, respectively. This leads to values of J = −1.37 cm−1 and g = 2.05. The same fitting method is applied to complex 3 to give values of J = 1.2 cm−1 and g = 2.25, showing that there is a ferromagnetic interaction between the Fe(III) and Ni(II) ions.  相似文献   

17.
Three new homopolynuclear complexes with azido bridges have been obtained by using [Cu(AA)(BB)]+ building-blocks (AA = acetylacetonate; BB = 1,10-phenanthroline or 2,2′-bipyridine). The reaction between [Cu(acac)(phen)(H2O)](ClO4) and NaN3 leads to a mixture of two compounds: a binuclear complex, [{Cu(acac)(phen)}21,3-N3)](ClO4) · 2H2O (1), and a linear tetranuclear one, [{Cu(acac)(phen)(ClO4)}2{Cu(phen)(μ1,1-N3)2}2] (2). The reaction between [Cu(acac)(bipy)(H2O)](ClO4) and NaN3 affords also a mixture of two compounds: [{Cu(acac)(bipy)}21,3-N3)]3(ClO4)3 · 3.75H2O (3) and [Cu(acac)(bipy)(N3)][Cu(acac)(bipy)(H2O)](ClO4) (4). The X-ray crystal structures of compounds 1-4 have been solved (for compound 4 the crystal structure was previously reported). In compounds 1 and 3, two {Cu(AA)(BB)} fragments are bridged by the azido anion in an end-to-end fashion. Two isomers, cis and trans with respect to azido bridge, were found in crystal 3. The structure of compound 2 consists of two Cu(II) central cations bridged by two μ1,1-azido ligands, each of them being also connected to a {Cu(acac)(phen)} fragment through another μ1,1-azido ligand. The cryomagnetic properties of the compounds 1 and 2 have been investigated and discussed. The magnetic behaviour of compound 1 shows the absence of any interactions between the metallic ions. In the tetranuclear complex 2, the magnetic interactions between the external and central copper(II) ions(J1), and between the central metallic ions (J2) were found ferromagnetic (J1 = 0.36 cm−1, J2 = 7.20 cm−1).  相似文献   

18.
Two novel bimetallic coordination polymers, [Cu(en)2][Mn(dca)4] (1) and [Cu(pn)2][Mn(dca)4] (2) (en, ethylenediamine; pn, 1,3-diaminopropane; dca, dicyanamide N(CN)2), have been synthesized and characterized. Both of them consist of Mndca anionic chains and chelate cations of copper. 1 has a sheet like architecture built by the [Cu(en)2]2+ cations and the homoleptic trans-[Mn(dca)4 2−]n chains. 2 shows unusual 3-D threefold interpenetrating diamond-like structure constructed by [Cu(pn)2]2+ cations and the homoleptic cis-[Mn(dca)4 2−]n chains. The magnetic susceptibilities obey the Curie-Weiss law with weak antiferromagnetic interactions.  相似文献   

19.
Two novel complexes, Cd(HTMA)(NC5H5)2 · 0.5CH3OH · 0.5DMF (1) and Cd(HTMA) · 2H2O (2), of cadmium (II)-trimesates are obtained from slow vapor diffusion and urea hydrolysis, respectively. The Cd(II) centers in the two complexes are bridged by three separate HTMA3− ligands using a same coordination fashion, which contains one monodentate and two chelating bidentate carboxyl groups to form the herringbone-like motif. The herringbone-like motif is further interlinked to construct the two-dimensional Cd(II)-HTMA layer, which is stacked by mutual π-stacking of pyridines for 1 and by hydrogen bond of waters for 2. Thermal stabilities of the two complexes were investigated and the results indicated that Cd(II)-TMA layers in the two complexes are stable still upon 190 °C.  相似文献   

20.
A trinuclear copper(II) complex, [Cu3(2,5-pydc)2(Me5dien)2(BF4)2(H2O)2] · H2O 1, has been constructed from 2,5-pyridine-dicarboxylato bridges (2,5-pydc2−) and N,N,N′,N″,N″-pentamethyl-diethylenetriamine (Me5dien) acting as a blocking ligand. The copper ions, within the centrosymmetric trinuclear cations, are connected by two 2,5-pydc2− bridges, with an intramolecular Cu···Cu separation of 8.432 Å. The central copper ion exhibits an elongated octahedral geometry, with semicoordinated ions, while the terminal ones are pentacoordinated (distorted square-pyramidal geometry). The cryomagnetic investigation of 1 reveals an antiferromagnetic coupling of the copper(II) ions (J = −5.9 cm−1, H = −JSCu1SCu2 − JSCu2SCu1a).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号