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1.
Abstract

Ternary copper(II) complexes of the type [Cu(His)A] (HisH=L-histidine, A=glycinato, L-valinato, L-alaninato, L-threoninato, L-serinato, or L-asparaginato) and [Cu(Glu)B]n- (GluH2=L-glutamic acid, B=glycinato, L-alaninato, L-valinato (n=1) or an amino-acid with positively charged protonated side chain such as L-asparagine, L-lysine, or L-ornithine (n=0)) have been investigated in aqueous solution by means of ESR and absorption spectra. It is suggested that in the ternary species the histidinate ion adopts a histamine-like bonding mode giving rise to CuN3O chromophores in the metal plane. Coordination in the bis-(glycine)-like mode is detected in the Glu-containing species. The spectral results have been used to postulate plausible structures for the bis-(histidinato)copper(II) complexes.  相似文献   

2.
以1-羟基-2-乙酰基咕吨酮和肼基二硫代甲酸甲酯缩合所得希夫碱(以H_2L表示),与Cu(Ⅱ)反应制得三种双核配合物。通过元素分析、红外、紫外-可见,磁化率、电子顺磁共振和循环伏安法等对配合物进行了表征和研究.表明这些配合物中,在所处化学环境不同的两个Cu(Ⅱ)之间存在较弱的自旋交换作用。桥联配体为醋酸根时,表现出不可逆的氧化还原性质,其余配合物显示准可逆的双电子转移过程.在吡啶存在时,醋酸根配位的双核铜配合物的氧化还原可逆性增加,其余配合物表现出可逆的两步单电子转移过程,同时还原电位正向移动.  相似文献   

3.
本文合成了两种新的铜(Ⅱ)5—氟尿密嘧啶配合物,[Cu(fuH)(Ac)(OH)](1)和[Cu_3O(fuH)_2(Ac)(OH)_3](2),进行了元素分析和红外光谱测定。从80-300K变温磁化率的数据表明,1和2均服从Curie-Weiss定律,θ值分别为-92K和-94K,证示在1和2分子内部均存在着反铁磁偶合作用。出1的室温多晶EPR谱测得g‖=2.30,g⊥=2.08和|A‖|=16.8mT,表明铜(Ⅱ)的几何构型为畸变四方形,其单电子主要集居于d_(x~2-y~2)轨道。同时对1和2的可能结构及反铁磁偶合作用机制进行了讨论。  相似文献   

4.
Abstract

Complex formation between copper(II) and 3-amino-3-phosphonoglutaric acid (Apga), an ambidentate aminophosphonate or citric acid derivative, was studied in aqueous solution by pH-potentiometry and EPR and electronic spectroscopy. Complexation with the parent molecules citric acid and tricarballylic acid was reinvestigated. The stoichiometries and stability constants of the complexes formed in these systems were determined at 25°C at an ionic strength of 0.20 mol dm?3 (KCl). Stability constant data and spectroscopic results revealed that in the acidic pH range Apga behaves as a citric acid derivative, forming the phosphonate-bridged dimeric species Cu2A2H2, while in the basic pH range, with decreasing proton competition at the amino binding site, it rearranges to yield mononuclear complexes involving aminophosphonate-like (NH2, PO3 2-, CO2) coordination.  相似文献   

5.
6.
苯并咪唑双铜配合物合成表征和生物活性   总被引:1,自引:1,他引:1  
本文报道三种新的N-羟乙基-N,N′,N′-三苯并咪唑甲基乙二胺双配合物合成和表征。变温磁化率分析结果表明配合和双铜离子间存在弱的反铁相互作用。ESR结果示配合物中Cu-N键具部分共价性。对配合物儿茶酚酶活性,体外抗癌活性及农药活性测定结果表明配合物具一定催化活性和生物活性。  相似文献   

7.
Abstract

The syntheses and crystal structures of [Co(nic)2(H2O)4] (1). [Co(iso)2(H2O)4] (2). [Cu(nic)2(H2O)4] (3), and [Cu(iso)2(H2O)4] (4) (nic = nicotinate; iso = isonicotinate) are reported. Complex 1 crystallizes in monoclinic, space group C2/m with cell parameters a =14.150(4). b = 6.883(2)., c = 8.497(2) Å, β= 118.28(2)° and Z = 2. The other crystals. 2. 3. and 4. are all triclinic, ; a = 9.777(3), b = 6.348(4), c = 6.888(3)Å, a= 113.10(6)., β= 110.55(3). γ = 97.61(5)°, and Z=l for 2; a = 7.0281(4), b = 7.7176(6), c = 8.6978(7)Å, a = 68.103(7), β = 68.526(5), γ = 62.550(6)°, and Z=1 for 3; a = 9.1807(4), b = 6.3334(3), c = 6.8871(3)Å, a= 108.213(4), β = 99.433(4), γ= 105.190(4)°, and Z= 1 for 4. The arrangements around the metal ions are trans-octahedra with two pyridyl nitrogens and two aqua oxygens in the equatorial positions and two aqua oxygens in the axial positions, although the Cu(II) complexes show a larger Jahn-Teller distortion.  相似文献   

8.
Abstract

Crystals of monoaquo(μ-5-methylpyrazine-2-carboxylato-N,O,O′), (5-methylpyrazine-2-carboxyato-N,O)di(μ-aquo-O,O)calcium(II) contain molecular ribbons in which two adjacent calcium(II) ions are bridged by two bidentate oxygen atoms donated by two ligand molecules on one side and bidentate oxygen atoms of two water molecules on the other. The coordination polyhedron around the Ca(II) ion is a pentagonal bipyramid. The vertices of its pentagonal base are composed of two bridging water oxygen atoms, two carboxylate oxygen atoms of two ligand molecules and a nitrogen atom belonging to one of the bridging ligands. A coordinated water molecule constitutes the apex of the pyramid on one side of the base, while the N, O bonding moiety of a second ligand molecule makes two apices on the other side of the base. The ribbons are held together by a system of hydrogen bonds.  相似文献   

9.
吡啶—2,6二甲酸铕配合物的晶体结构研究   总被引:2,自引:0,他引:2  
合成了吡啶—2,6二甲酸铕配合物Na_3[Eu(DPC)_3]·14H_2O(DPC为吡啶—2,6二甲酸根)晶体,对该配合物的红外光谱、荧光光谱、热谱及电导等性质进行了研究.单晶结构分析表明,Na_3[Eu(DPC)_3]·14H_2O属三斜晶系,空间点群P(?).晶胞参数:a=1.1000(10),b=1.7268(22),c=1.0314(14)nm;α=102.53(11)°,β=107.05(8)°,γ=74.53(9)°;V=1.7845nm~3;Z=2;D_c=1.80g/cm~3;μ=18.9cm~(-1).吡啶—2,6二甲酸以三齿配位,铕的配位数为9,其配位多面体为畸变的三帽三角棱柱体.  相似文献   

10.
Abstract

Mn(II) cations in the crystals of trisaquobis(μ-thiophen-2-carboxylato-O,O′)(thiophen-2-carboxylato-O)manganese(II) monohydrate are bridged by oxygen atoms donated by bidentate carboxylic groups of two thiophen-2-carboxylate ligands. In addition, each Mn(II) ion is coordinated by an oxygen atom of a monodentate carboxylic group of this ligand and three oxygen atoms of water molecules. The coordination around the Mn(II) cation is octahedral. The bridging of the ligands results in molecular ribbons propagating in the c-direction of the crystal held together by C?H…O hydrogen bonds. The crystal structure of diaquobis(μ-furan-3-carboxylato-O,O′)di(μ-furan-3-carboxylato-O,O)(μ-aqua-O)manganese(II) consists of dinuclear structural units. In each molecule Mn(II) cations are O,O′ bridged by oxygen atoms of bidentate carboxylic groups of two furan-3-carboxylate ligands and have a water located between the Mn cations. The units are O,O′ bridged to Mn(II) ions located in adjacent units by bidentate oxygen atoms, forming molecular ribbons extending in the c-direction. Octahedral coordination around each Mn(II) ion is completed by two water molecules. The octahedra around two adjacent metal ions in the unit share a common apex - the bridging oxygen atom of the water molecule. The ribbons are held together by C?H…O hydrogen bonds between furan ring oxygen atoms and the carbon atoms of adjacent furan rings.  相似文献   

11.
Abstract

The title compound [Cu3Br4C28H28N4O2] is a type of polymeric three-centre octahedral-trigonal planar coordination complex. The copper(II) atom located at a centre of symmetry is six-coordinate with two bidentate (N3, O1) ligands of acetone-1-naphthoylhydrazone forming the equatorial plane and two bromine ions in axial positions (Cul-Brl = 2.946(1)Å). The ligands are in trans positions. The Cu(I) atoms are in trigonal planar coordination by two bridging Br? ions (Cu2-Br2 = 2.412(1)Å, Cu2-Br2? = 2.407(2)Å) which connect two Cu(I) atoms and a third bromine ion shared with the octahedral Cu(II) ion (Cu2-Br1 = 2.304(1)Å). The arrangement forms an infinite chain along the b axis.  相似文献   

12.
本文合成了一组新的不对称的双核配合物,[Cu_2(C_2O_4)_2terp]和〔Cu Zn(C_2O_4)_2terp〕(图1),terp表示联三吡啶。配合物〔Cu_2(C_2O_4)2terp〕的变温磁化率已测,其数值已用最小二乘法与Bleaney-Bowers方程拟合,求得交换积分J=-47.20cm~(-1)。文中还用Kahn理论解释了这种较弱的反铁磁自旋交换作用。  相似文献   

13.
Abstract

The crystal structures of two mixed-ligand copper(II) complexes having iminodiacetate(2-) (IDA) or N-carboxymethyl-D,L-threoninato(2-) ion (CMT) as terdentate ligands and imidazole (ImH) as an N-heterocyclic ligand are reported. Both compounds crystallize in the orthorhombic system, space group Pbca with Z = 8. Aqua(imidazole)(iminodiacetato)copper(II) monohydrate (I,R = 0.065, R w = 0.075) consists of H2O molecules and [Cu(IDA)(ImH)(H2O)] complex units in a hydrogen bonding network. The structure of imidazole(N-carboxymethyl)-D,L-threoninatocopper(II) (IV, R = 0.066, Rω 0.078) is built up of hydrogen bonded polynuclear chains. In both compounds the Cu(II) ion exhibits a flattened and distorted square-based pyramidal coordination, with a terdentate aminoacidate ion, IDA or CMT, and one ImH ligand at the base and H2O (in I) or the oxygen atom of the OH side chain from one adjacent CMT ion (in IV) as the fifth apical ligand. The nearly coplanar conformation of the two five-membered chelate rings in I and IV is discussed in connection with the known structure of corresponding aquacomplexes (with H2O instead of ImH) and the ability of terdentate aminoacids to give ternary Cu(II) complexes having two N-heterocyclic donors (2 ImH or one 2,2′-bipy) per Cu(II) atom.  相似文献   

14.
研究了新的水溶性显色剂2-(2,3,5-三氮唑偶氮)-1,8-二羟基-3,6-萘二磺酸与铜的显色反应,并利用该显色反应建立了测定铜的新方法。在pH=5.52的HAc-NaAc缓冲液中,该试剂与铜形成蓝绿色稳定络合物,λ_(max)为550.8nm,表观摩尔吸光系数为2.44×10~4L/(mol·cm),铜的浓度在0.0~1.0μg/mL范围内符合比耳定律。其他金属离子共存时,不经预分离也无需加掩蔽剂,可直接测定食品及环境水样中的微量铜,操作简便,结果准确。  相似文献   

15.
16.
酸性磷(瞵)酸酯是一类重要的萃取剂,它们对金属离子的萃取性能和机理研究巳有报导,但大多限于溶液体系。酸性磷酸酯金属萃合物的研究也有报导,但对固态烷基膦酸单烷基酯金属萃合物方面的报导较少。本文报导2-乙基已基膦酸2-乙基已基酯(简称HEH(EH)P或HA)金属(M=Co、Ni、Cu、Zn)固体萃合物的磁性,电子光谱和红外光谱,结合热分析结果对萃合物的成键特性和可能构型进行了讨论。  相似文献   

17.
人们在探索新的有效抗癌药物时,发现了一些Schiff碱及其和某些金属生成的配合物具有抗癌作用。为研究此类配合物的抗癌作用和结构的关系,我们合成了一系列Schiff碱类配合物。 本文合成了Cu(Ⅱ)与N(2-羟基乙基)水杨醛亚胺配合物,培养出了单晶,通过X射线单晶衍射确定了配合物的晶体和分子结构,并对其热分解过程进行了初步探讨。  相似文献   

18.
Abstract

A series of mono- and dinuclear complexes of Ni(II) and Co(II) with two hexadentate ligands α,α′-bis(bis(2-(diphenylphosphino)ethyl)amino)ethane(BDPE) and α,α′-bis(bis(2-(diphenylphosphino)ethyl)-amino)-m-xylene (BDPX) were synthesized and chracterized by means of elemental analyses, molar conductance, magnetic susceptibilities, infrared, electronic and 31P NMR data. The molecular structure of a mononuclear Ni(II) complex, [Ni(BDPE)](CIO4)2.CH2Cl2, was established by single-crystal X-ray diffraction methods. Crystal data: C59H62NiCl4N2O8P4, M = 1250.98, orthorhombic, space group Pbca, V= 11834.3(7) Å3, Z= 8, a= 10.817(1), b = 31.683(7), c=34.538(1) Å, final R 0.055 (R w = 0.057) for 3118 observed reflections. The Ni(II) ion exists in a slightly distorted square planar geometry, the coordination sites being two phosphorous and two tertiary nitrogen atoms of the ligand. Electrochemical studies of the complexes were also carried out.  相似文献   

19.
本文采用电导、pH滴定法研究了乙醇-水溶液中希土与1′-苯基-3′-甲基-5′-氧代吡唑-4′-基乙醛酸(简称H_2A)的配位反应.合成了15种新的希土固态配合物.通过元素分析、化学分析、水份分析确定了配合物的化学组成为RE(HA)_3·nH_2O(RE=Ce、Pr、Sm、Tm、Lu、n=1;RE=La、Nd、Eu、Gd、Tb、Dy、Ho、Er、Yb、Y,n=1-2).并对配合物的红外光谱、核磁共振谱、热稳定性、紫外光谱、溶解性及摩尔电导进行了测定.  相似文献   

20.
合成了五个2,6-二乙酰吡啶缩肼基硫代甲酸酯双希夫碱合铜(Ⅱ)配合物,用元素分析、磁化率、红外光谱及紫外-可见光谱等对它们进行了表征,研究了配合物的电化学性质和Cu_3L_2~2X_2(X=Cl~-、SCN~-)的光电子能谱。结果表明:五个Cu(Ⅱ)配合物均为三核配合物,在Cu_3L_2~2(SCN)_2中存在Cu(Ⅱ)间的自旋—交换作用。  相似文献   

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