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1.
Syntheses and Properties of Molecular Conductors based on dmit isologous Chelates. Crystal and Molecular Structure of Tetramethylammonium-bis-[bis(1,3-dithiole-2-selone-4,5-diselenolato)nickelate]; [(CH3)4N] [Ni(dsise)2]2 Syntheses and properties of dichalcogenolate chelates of the general type [(CH3)4N]n[ML2] (n ≤ 2; M = Ni, Pd, Pt); L = dmit (1,3-dithiole-2-thione-4,5-dithiolate), dmise (1, 3-dithiole-2-selone-4,5-dithiolate), dsit (1, 3-dithiole-2-thione-4,5-diselenolate), dsise (1, 3-dithiole-2-selone-4,5-diselenolate), dsis (1, 3-diselenole-2-selone-4,5-diselenolate) are reported. The effects of the chalcogen atom variation in these chelates are discussed by using UV/VIS, IR, EPR, cyclovoltammetric and conductivity data. The x-ray structure of [(CH3)4N][Ni(dsise)2]2 (space group Pccn, a = 7.427(1), b = 39.144(5), c = 11.836(1) Å) and the conductivity of the crystal (12 S cm?1 at room temperature) are given.  相似文献   

2.
Synthesis and Characterization of Metallocene Chelates of Heterocyclic 1,2-Diselenolates Synthesis and properties of metallocen diselenolates Cp2RML (CpR = η5-C5H4CH3 (Cp′); η5-C5(CH3)4 C2H5 (Cpo)) of titanium(IV) and vanadium(IV) with L = dsit (1,3-dithiole-2-thione-4,5-diselenolate), dsise (1,3-dithiole-2-selone-4,5-diselenolate) dsitse (1,3-thiaselenole-2-selone-4,5-diselenolate) and dsis (1,3-diselenole-2-selone-4,5-diselenolate) are described. The structures of these compounds in solution are discussed using 1H, 13C, 77Se NMR and EPR data. Their voltammetric behaviour is investigated in dichloromethane. The activation parameters of the chelate ring inversion of the titanocene diselenolates (Cp2RTiL) and the x-ray structures of Cp2′Ti(dsit), Cp2oTi(dsit); Cp2oTi(dsise) (2 modifications) and Cp2oTi(dsis) are reported.  相似文献   

3.
Coordination Chemistry of 1,3-Dithiole-2-selone-4,5-diselenolate (dsise) and 1,3-Dithiole-2-selone-4,5-dithiolate (dmise). Crystal and Molecular Structure of Tetrabutylammonium bis(1,3-dithiole-2-selone-4,5-diselenolato)nickelate(II) and -(III), [(n-C4H9)4N]2[Ni(dsise)2 and (n-C4H9)4[Ni(dsise)2] Syntheses and properties of metal(II) and metal(III) bis-chelates of 1,3-dithiole-2-selone-4,5-diselenolate (dsise), of the general type (Bu4N)n)M(dsise)2] (n =2 : M = Zn, Cd, Hg, Cu, Ni, Pd; n = 1: M = Ni, Au) are reported and compared with chelates of the isologue 1,3-dichalcogenole-2-chalcogenoe-4,5-dichalcogenolate (i. r., 13C-n. m. r., e. p. r., cyclovoltammetric data). The unexpected rearrangement during the syntheses of dsise and 1,3-dithiole-2-selone-4,5-diselenolate (dmise) is characterized by ab-initio SCF calculations. The x-ray structures of (Bu4N)2[Ni(dsise)2] (space group P21/c, a = 8.5556(13) Å, b = 15.0009(12) Å, c = 19.696(3) Å, β = 96.018(7)°, V = 2513.9(5) Å3, Z = 2) and Bu4N[Ni(dsise)2] (space group C2/c, a = 25.133(6) Å, b = 9.828(4) Å, c = 18.104(7) Å, β = 132.81(1)°, V = 3281(2) Å3, Z = 4) are given.  相似文献   

4.
Three mononuclear copper(II) complexes of copper nitrate with 2, 6‐bis(pyrazol‐1‐yl)pyridine ( bPzPy ) and 2, 6‐bis(3′,5′‐dimethylpyrazol‐1‐yl)pyridine ( bdmPzPy ), [Cu(bPzPy)(NO3)2] ( 1 ), [Cu(bPzPy)(H2O)(NO3)2] ( 2 ) and [Cu(bdmPzPy)(NO3)2] ( 3 ) were synthesized by the reaction of copper nitrate with the ligand in ethanol solution. The complexes have been characterized through analytical, spectroscopic and EPR measurements. Single crystal X‐ray structure analysis of complexes 1 and 2 revealed a five‐coordinate copper atom in 1 , whereas 2 contains a six‐coordinate (4+2) CuII ion with molecular units acting as supramolecular nodes. These neutral nodes are connected through O–H ··· O(nitrate) hydrogen bonds to give couples of parallel linear strips assembled in 1D‐chains in a zipper‐like motif.  相似文献   

5.
The oxido-pincer ligand pydotH2 (2,6-bis(1-hydroxy-1-o-tolyl-ethyl-η2O,O′)pyridine) forms two different CuII containing complexes when prepared from anhydrous CuCl2. A combination of EPR spectroscopy and EXAFS allowed to structurally characterise the light-green dimer of the formula [(pydotH2)CuCl(μ-Cl)2ClCu(pydotH2)] and the penta-coordinate olive-green monomer [(pydotH2)CuCl2]. The molecular entities imply that the ligand remains protonated upon coordination. When dissolved in DMF both compounds form monomeric species [(pydotH2)CuCl2(DMF)] which could be characterised in detail by EPR, UV-Vis/NIR spectroscopy and electrochemical measurements. The assignments were supported by comparison with CuII complexes of the related ligands 2,6-bis(hydroxymethyl)pyridine (pydimH2) and 2,6-bis(1-hydroxy-1-methyl)pyridine (pydipH2).  相似文献   

6.
The synthesis and the structures of (i) the ligand N,N‐Diethyl‐N′‐3,5‐di(trifluoromethyl)benzoylthiourea HEt2dtfmbtu and (ii) the NiII and PdII complexes of HEt2dtfmbtu are reported. The ligand coordinates bidendate forming bis chelates. The NiII and the PdII complexes are isostructural. The also prepared CuII complex could not be characterized by X‐ray analysis. However, the preparation of diamagnetically diluted powders Cu/Ni(Et2dtfmbtu)2 and Cu/Pd(Et2dtfmbtu)2 suitable for EPR studies was successful. The EPR spectra of the Cu/Ni and Cu/Pd systems show noticeable differences for the symmetry of the CuS2O2 unit in both complexes: the Cu/Pd system is characterized by axially‐symmetric g< and A cu tensors; for the Cu/Ni system g and A Cu have rhombic symmetry. EPR studies on frozen solutions of the CuII complex show the presence of a CuII‐CuII dimer which is the first observed for CuII acylthioureato complexes up to now. The parameters of the fine structure tensor were used for the estimation of the CuII‐CuII distance.  相似文献   

7.
Summary A variety of metal(II) complexes of 2-carbethoxypyridine (L) have been prepared and characterised. With metal(II) chlorides the bis complexes can be formulated [ML2Cl2]o (M=CuII, NiII, CoII, FeII or MnII). The complexes are six-coordinate with 2-carbethoxypyridine acting as a bidentate ligandvia the pyridine nitrogen and the carbonyl group of the ester. The chloro complexes are nonelectrolytes in nitroethane; magnetic susceptibility measurements, i.r. and d-d electronic spectra are reported. With metal(II) perchlorate salts the complexes can be formulated as six-coordinate [ML2 (OH2)2] [ClO4]2 species containing ionic perchlorate. The ester exchanges of some of these complexes with a variety of primary alcohols have been investigated.  相似文献   

8.
Synthesis and characterization of seven new complexes [Cu(2‐MeSnic)2(CH3OH)]2 (where 2‐MeSnic is 2‐methylthionicotinate), [Cu(2‐MeSnic)2L2]2 (where L is pyridine — py, ethylnicotinate — Etnic and butylnicotinate — Bunic), [Cu(2‐MeSnic)2L2(H2O)2] (where L is py and nicotinamide — nia) and [Cu(2‐MeSnic)2(N‐Menia)2(H2O)2]·2H2O (where N‐Menia is N‐methylnicotinamide) are reported. The characterization were based on elemental analysis, infrared, electronic and EPR spectra, and magnetic susceptibility measurements over a temperature range of 1.8 — 300 K or 70 — 300 K. Three complexes of different type were studied by X‐ray analysis. The molecule of [Cu(2‐MeSnic)2(CH3OH)]2 has dimeric paddle‐wheel cage structure with a tetragonal pyramidal arrangement around CuII. The dimer results from the fact that carboxyl groups of four 2‐MeSnic anions function as bridging in a syn‐syn arrangement. On the other hand [Cu(2‐MeSnic)2(py)2]2 forms dimers with hexacoordinated CuII atoms in highly distorted coordination octahedra, each with two oxygen atoms of bridging carboxyl groups in an anti‐anti arrangement of two 2‐MeSnic anions, with two oxygen atoms of one asymmetrically chelating 2‐MeSnic anion and with two nitrogen atoms of two pyridine ligands. The temperature independent EPR spectrum for this complex exhibits an axial signal which corresponds to almost isolated S = 1/2 magnetic ions. Magnetic data for the dimer show a weak antiferromagnetic interaction between the two metal ions with J = —0.65 cm—1. The CuII atom in complex [Cu(2‐MeSnic)2(py)2(H2O)2] is hexacoordinated in an elongated centrosymmetrical tetragonal‐bipyramidal arrangement (4 + 2). Based on the molecular structure the electronic, infrared, electron paramagnetic resonance spectra and magnetic properties are discussed and stereochemistry as well as the mode of ligand coordination in new solid complexes under study have been determined.  相似文献   

9.
In the title compound, [Cu(C7H3N2O4)(C4H5N2)(H2O)], (I), pyridine‐2,6‐dicarboxylate (pydc2−), 2‐aminopyrimidine and aqua ligands coordinate the CuII centre through two N atoms, two carboxylate O atoms and one water O atom, respectively, to give a nominally distorted square‐pyramidal coordination geometry, a common arrangement for copper complexes containing the pydc2− ligand. Because of the presence of Cu...Xbridged contacts (X = N or O) between adjacent molecules in the crystal structures of (I) and three analogous previously reported compounds, and the corresponding uncertainty about the effective coordination number of the CuII centre, density functional theory (DFT) calculations were used to elucidate the degree of covalency in these contacts. The calculated Wiberg and Mayer bond‐order indices reveal that the Cu...O contact can be considered as a coordination bond, whereas the amine group forming a Cu...N contact is not an effective participant in the coordination environment.  相似文献   

10.
Summary Dicyanamide complexes of CuII, NiII and CoII of the type M[N(CN)2]2L2, where L = benzimidazole, 2-methyl- or 2-ethylbenzimidazole, have been prepared and studied by spectroscopy and magnetochemistry. The complexes, except for Co[N(CN)2]2 (benzimidazole)2, are six-coordinate, involving bidentate bridging dicyanamide groups. While the NiII complexes have practically octahedral structures, the CuII complexes are pseudooctahedral with similar tetragonal distortion. The ligand field strength in these complexes depends mainly on the steric effect of the benzimidazole ligands. The CoII complex of benzimidazole is monomeric tetrahedral, but that of 2-ethylbenzimidazole is tetragonal octahedral. The oridging function of dicyanamide in the six-coordinate complexes is realized either through both cyanide or through amide and cyanide nitrogens. The complex Cu[N(CN)2]2 (2-methylbenzimidazole)2 is a weak antiferromagnet (J = -0.1 cm–1), exhibiting under ca. 15 K a long-range antiferromagnetic ordering.  相似文献   

11.
Mixed Ligand Complex Formation by Thermal Reactions of Metal(II) Thioselenocarbamate Chelates. EPR and Mass Spectrometric Investigations At higher temperatures metal(II) thioselenocarbamates M(R2tsc)2 (M = Cu, Ni, Pd, Pt) react to form M(R2tsc)(R2dsc) and M(R2tsc)(R2dtc) (dtc = dithiocarbamate, dsc = diselenocarbamate) mixed-ligand chelates. If CuII species are participated the mixed-ligand complex formation can be the followed by EPR spectroscopy. The reaction is irreversible, and the rate depends on the temperature, the substituent R, and the solvent used. The complexes M(Et2tsc)(Et2dsc) and M(Et2tsc)(Et2dtc) formed during the thermal reaction of M(Et2tsc)2 chelates (M = Ni, Pd, Pt) can be detected by EPR spectroscopy using the ligand-exchange reaction with [Cu(mnt)2]2?(mnt = maleonitriledithiolate). As results the spectra of [Cu(mnt)(Et2tsc)]?, [Cu(mnt)(Et2dsc)]? and [Cu(mnt)(Et2dtc)]? are observed.  相似文献   

12.
Summary New complexes of general formulae [Ni(HL)2], [ML]·H2O and [Cu(HL)X] (H2L = pyrrole-2-aldehyde Schiff bases ofS-methyl- andS-benzyldithiocarbazates; X = Cl or Br; M = NiII, CuII, ZnII or CdII) were prepared and characterized by a variety of physicochemical techniques. The Schiff bases coordinate as NS bidentate chelating agents in [Ni(HL)2] and [Cu(HL)X], and as tridentate NNS chelates in [ML] (M = NiII, CuII, ZnII or CdII). Both the [Ni(HL)2] and [NiL] complexes are diamagnetic and square-planar. Based on magnetic and spectroscopic evidence, thiolate sulphur-bridged dimeric square-planar structures are assigned to the [Cu(HL)X] and [ML] (M = NiII or CuII) complexes. The complexes ML (M = ZnII or CdII) are polymeric and octahedral.  相似文献   

13.
The reaction of copper(II) perchlorate with the hydrochloride salt of 3,6,9,15-tetra-azabicyclo[9.3.1]penta-deca-1,11,13-triene (L1) in acetonitrile forms two macrocyclic complexes that can be characterized: [L1CuIICl][ClO4] (1) and [L1CuIICl]2[CuCl4] (2). The structural, electronic, and redox properties of these complexes were studied using spectroscopy (EPR and UV–visible) and electrochemistry. In addition, the solid-state structure of 1 was obtained using X-ray diffraction. The copper(II) is five-coordinate ligated by four N-atoms of the macrocycle and a chloride atom. EPR studies of 1 both in DMF and aqueous solution indicate the presence of a single copper(II) species. In contrast, EPR studies of 2 performed in frozen DMF and in the solid-state reveal the presence of two spectroscopically distinct copper(II) complexes assigned as [L1CuIICl]+ and [CuIICl4]2?. Lastly, electrochemical studies demonstrate that both [L1CuIICl]+ and [CuIICl4]2? are redox active. Specifically, the [L1CuIICl]+ undergoes a quasi-reversible Cu(II)/(I) redox reaction in the absence of excess chloride. In the presence of chloride, however, the chemical irreversibility of this couple becomes evident at concentrations of chloride that exceed 50 mM. As a result, the presence of chloride from the chemical equilibrium of this latter species impedes the reversibility of the reduction of [L1CuIICl]+ to [L1CuICl]0.  相似文献   

14.
Summary The preparation and characterization of CuII, CoII, NiII and HgII complexes containing 1,4-diphenylthiosemicarbazide (DPhTSC) of the type [Cu(DPhTSC-H)X.H2O]nH2O (X= Cl, Br or Ac; n=0 or 1) · [M(DPhTSC-H)2yH2O] (M=CoII or NiII; y=0 or 1) and [Hg(DPhTSC)Cl2]2 H2O and [Cu(D-PhTSC)2SO4]H2O are reported. The stereochemistry of the complexes have been studied with the help of magnetic and electronic measurements. The anomalous magnetic moments observed in all cases have been explained. The i.r. spectral studies have been used to determine the bonding sites in the complexes.  相似文献   

15.
Electronic spectra (340–800 nm; 298.2 K), liquid (298.2 K) and frozen solution (77 K) EPR spectra and electrolytic conductivities (298.2 K) have been measured for Cu(CH3CO2)2 over the whole range of compositions of the mixed pyridine-water solvent. The results have been interpreted in terms of the possible coordination equilibria in the solution. They support the strong tendency of the CuII ion to coordinate pyridine molecules in aqueous solutions, revealed by other CuII salts. Even small amounts of pyridine were found to withdraw the electrolytic dissociation of the aqueous Cu(CH3CO2)2 solutions, probably, through the enhancement of the CuII ion interactions.  相似文献   

16.
Synthesis, Structures, EPR and ENDOR Investigations on Transition Metal Complexes of N, N‐diisobutyl‐N′‐(2, 6‐difluoro)benzoyl selenourea The synthesis and the structures of the NiII and PdII complexes of the ligand N, N‐diisobutyl‐N′‐(2, 6‐difluoro)benzoylselenourea HBui2dfbsu are reported. The ligands coordinate bidentately forming bis‐chelates. The structure of the ligand could not be obtained, however, the structure of its O‐ethyl ester will be reported. Attempts to prepare the CuII complex result only in the formation of oily products. However, the CuII complex could be incorporated into the corresponding NiII and PdII compounds. From this diamagnetically diluted powder and single‐crystal samples were obtained being suitable for EPR‐ENDOR measurements. We report X‐ and Q‐band EPR investigations on the systems [Cu/Ni(Bui2dfbsu)2] and [Cu/Pd(Bui2dfbsu)2] as well as a single‐crystal X‐band EPR study for [Cu/Ni(Bui2dfbsu)2]. The obtained 63, 65Cu and 77Se hyperfine structure tensors allow a determination of the spin‐density distribution within the first coordination sphere. In addition, orientation selective 19F Q‐band pulse ENDOR investigations on powder‐samples of [Cu/Ni(Bui2dfbsu)2] have been performed. The hyperfine structure tensors of two intramolecular 19F atoms could be determined. According to the small 19F couplings only a vanishingly small spin‐density of < 1 % was obtained for these 19F atoms.  相似文献   

17.
Synthesis, Structure and EPR Investigations of binuclear Bis(N,N,N?,N?‐tetraisobutyl‐N′,N″‐isophthaloylbis(thioureato)) Complexes of CuII, NiII, ZnII, CdII and PdII The synthesis of binuclear CuII‐, NiII‐, ZnII‐, CdII‐ and PdII‐complexes of the quadridentate ligand N,N,N?,N?‐tetraisobutyl‐N′,N″‐isophthaloylbis(thiourea) and the crystal structures of the CuII‐ and NiII‐complexes are reported. The CuII‐complex crystallizes in two polymorphic modifications: triclinic, (Z = 1) and monoclinic, P21/c (Z = 2). The NiII‐complex was found to be isostructural with the triclinic modification of the copper complex. The also prepared PdII‐, ZnII‐ and CdII‐complexes could not be characterized by X‐ray analysis. However, EPR studies of diamagnetically diluted CuII/PdII‐ and CuII/ZnII‐powders show axially‐symmetric g and A Cu tensors suggesting a nearly planar co‐ordination within the binuclear host complexes. Diamagnetically diluted CuII/CdII powder samples could not be prepared. In the EPR spectra of the pure binuclear CuII‐complex exchange‐coupled CuII‐CuII pairs were observed. According to the large CuII‐CuII distance of about 7,50Å a small fine structure parameter D = 26·10?4 cm?1 is observed; T‐dependent EPR measurements down to 5 K reveal small antiferromagnetic interactions for the CuII‐CuII dimer. Besides of the dimer in the EPR spectra the signals of a mononuclear CuII species are observed whose concentration is T‐dependent. This observation can be explained assuming an equilibrium between the binuclear CuII‐complex (CuII‐CuII pairs) and oligomeric complexes with “isolated” CuII ions.  相似文献   

18.
The title compound, [Cu(Cr2O7)(C10H8N2)2], a new mixed‐metal molecular compound, contains isolated molecular units, each comprised of one CuII atom coordinated to two 2,2′‐bi­pyridine ligands and also to an oxy­gen vertex of a dichromate anion. The CuII atom has an approximate trigonal–bipyramidal geometry, which is consistent with previous studies. Both enantiomers of the chiral complex mol­ecule are present and are related by inversion centers. In a reported pyridine analogue, achiral [Cu(Cr2O7)(pyridine)4] chains pack in the non‐centrosymmetric space group Pna21. Differences in the organic ligands influence the chirality and dimensionality of the Cu—Cr2O7 bonding.  相似文献   

19.
Summary Nine different CuII(sulf)2 and three mixed CuII(sulf)2X2–3 (X=NH3 or pyridine) derivatives were prepared from CuII and sulfanilamides (sulfH=sulfadiazine, sulfadimethoxine, sulfadimidine, sulfamerazine, sulfamethoxydiazine, sulfamethoxypyridazine, sulfapyridine, sulfathiazole and sulfisomidine) in alkaline solution and their e.s.r., i.r. and ligandfield spectroscopic properties were evaluated. Two types of Cu(sulf)2 complexes were formed: dimeric and monomeric/ polymeric species.  相似文献   

20.
EMR studies of bis(benzene-dithiocarboxylato)copper(II) in the form of the pure solid sample, in solution as well as magnetically diluted in the host lattices of the corresponding complexes of NiII, ZnII, PdII, and PtII are reported. Two different samples (violet and blue) have been obtained in the NiII complex host lattice with EMR spectra indicating a superposition of several individual CuII signals. The EMR spectrum of the violet sample is explained by a superposition of the individual signals of (thio-, perthio-carboxylate)CuII and bis(perthiocarboxylate)CuII while that for the blue Cu/Ni(dtb)2 complex, as well as for Cu/Pd (dtb)2 is explained by different positions of the CuII species in the host lattices. The EMR spectrum typical for the magnetically diluted sample caused by self redox reaction has been recorded in the pure solid sample of copper(II) dithiocarboxylate complex.  相似文献   

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