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1.
Two new μ-oxamido-bridged binuclear copper(II) complexes with formulae of [Cu2(heae)(pic)2] (1) and [Cu2(heae)(Me2phen)2](ClO4)2 · H2O (2), where heae and pic stand for the anion of N,N′-bis(N-hydroxyethylaminoethyl)oxamide and 2,4,6-trinitrophenol, respectively, and Me2phen represents 2,9-dimethyl-1,10-phenanthroline; have been synthesized and characterized by elemental analyses, molar conductivity measurements, IR and electronic spectra studies. The crystal structures of the two binuclear copper(II) complexes have been determined by X-ray single-crystal diffraction. In both the two binuclear complexes the central two copper(II) atoms are bridged by trans-heae. In complex 1 the coordination environment around each copper(II) atom can be described as a distorted octahedral geometry, while in complex 2 each copper(II) atom displays a square-pyramid stereochemistry. Hydrogen bonding and π-π stacking interactions link the binuclear copper(II) complex 1 or 2 into a 3D infinite network. The cytotoxicities of the two binuclear copper(II) complexes were tested by Sulforhodamine B (SRB) assays against human hepatocellular carcinoma cell SMMC-7721 and human lung adenocarcinoma cell A549. Both of the two binuclear copper(II) complexes exhibit potent cytotoxic effects against SMMC-7721 and A549 cell lines. The interactions of the two binuclear complexes with herring sperm DNA (HS-DNA) are investigated by using absorption and emission spectra and electrochemical techniques and viscometry. The results suggest that both the two binuclear copper(II) complexes interact with HS-DNA in the mode of intercalation with the intrinsic binding constants of 1.73 × 105 M−1 (1) and 1.92 × 106 M−1 (2). The influence of structural variation of the terminal ligands in the binuclear complexes on DNA-binding properties is preliminarily discussed.  相似文献   

2.
2,2′-Dipyridylketone (dpk), when acting as a chelating ligand for PdII or PtII, is in slow equilibrium with its corresponding gem-diol form (dpk·H2O). In D2O, equilibrium constants K = (dpk·H2O)/(dpk) change from ca. 0.04 for the free ligand to ca. 3 in the corresponding complexes with cis-[Pt(H2O)2]2+. In solution, species of both ligands can be identified and differentiated by 1H NMR spectroscopy, and in the trinuclear μ-OH bridged PtII complex [Pt3(μ-OH)3(dpk·H2O)2(dpk)](NO3)3·4.5H2O (4), both types of ligands are present simultaneously in a ratio of (dpk·H2O):(dpk) = 2. As demonstrated with a series of PdII complexes containing dpk·H2O and dpk ligands, a straightforward differentiation is possible when DMSO-d6 is used as solvent, because then also the OH protons of dpk·H2O are observable. It is also shown that monocrystalline [PdCl2(dpk·H2O)] (1), when dissolved in DMSO-d6, partially converts, with loss of H2O, to [PdCl2(dpk)].  相似文献   

3.
The synthesis and characterization of rare-earth (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) thiocyanate adducts with tripiperidinophosphine oxide (tpppO) with general formula (RE)(SCN)3(tpppO)3 are reported. Conductance measurements in acetonitrile indicate the non-electrolytic nature of the complexes. Infrared absorption spectra evidence that the SCN ion coordinates through the nitrogen atom (isothiocyanate form) and that tpppO coordinates through the phosphoryl oxygen. X-ray powder patterns suggest the existence of three different crystal forms: (1) La; (2) an isomorphous series including Ce, Nd and Pr; and (3) another isomorphous series, including Sm, Gd, Eu, Ho, Er, Tb, Lu and Y. The visible spectra of the Nd adduct and the calculated parameters β = 0.98, b1/2 = 0.072 and δ = 1.06 indicate that the metal-ligand bonds are essentially electrostactic. The emission spectra of the Eu compound showed 5D0 → 7FJ bands (J = 0, 1, 2), suggesting a C3v symmetry for the coordination polyhedron. The lifetime of the 5D0 state is 1.28 ms. The emission spectra of the Tb complex presented 5D4 → 7FJ bands (J = 4, 5, 6) and the Dy complex showed the 4F9/2 → 6H13/2 band. The structure of the Pr complex showed that the coordination polyhedron is a trigonal antiprism, with the isothiocyanate anions in one base and three tpppO ligands in the other. Thermal analyses (TG-DTG) were carried out for the Ce, Nd and Gd adducts. Mass losses start between 250 and 334 °C. The final residues at 1300 °C are the corresponding phosphates.  相似文献   

4.
Two new neutral, binuclear CuIICuII bis(oxamato) complexes with the formula [Cu2(opba)(pmdta)(MeOH)] · 1/2MeOH · dmf (3) and [Cu2(nabo)(pmdta)(MeOH)] (4), with opba = o-phenylene-bis(oxamato), nabo = 2,3-naphthalene-bis(oxamato), pmdta = N,N,N′,N″,N″-pentamethyldiethylenetriamine and dmf = dimethylformamide have been synthesized and their crystal structures have been determined. The structure of 3 consists of dimeric [Cu2(opba)(pmdta)(MeOH)] entities, joined together by mutual intermolecular Cu?O contacts of the Cu2+ ion of one [Cu(opba)]2− complex fragment and one carboxylate atom of the oxamato group of a second [Cu(opba)]2− complex fragment. The structure of 4 consists of neutral binuclear complexes joined together by hydrogen bonds and π-π interactions, giving rise to an unique supramolecular 1D-chain. The magnetic properties of 3 and 4 were studied by susceptibility measurements versus temperature. For the intramolecular J parameter, identical values of (−114 ± 2) cm−1 (3) and (−112 ± 2) cm−1 (4) were obtained.  相似文献   

5.
The binuclear mixed valence copper(I/II) compound [CuI(CN)3CuII(tn)2] (1) (tn = propane-1,3-diamine) and its acetonitrile adduct [CuI(CN)3CuII(tn)2] · 2MeCN (2) have been synthesized. Complex 1 crystallizes triclinic, space group , a = 8.117(2) Å, b = 8.389(2) Å, c = 11.920(2) Å, α = 108.728(3)°, β = 100.024(3)°, γ = 104.888(4)°, Z = 2, and compound 2 monoclinic, space group P21/m, a = 8.752(2) Å, b = 13.243(3) Å, c = 9.549(2) Å, β = 114.678(4)°, Z = 2. In both crystal structures, the binuclear [CuI(CN)3CuII(tn)2] complex with slightly different bonding geometries is formed. One of the three nitrogen atoms of a CuI(CN)3 moiety is coordinated to Cu(II) at the apex of a square-pyramid with two chelating ligands tn on its base. The shortest intramolecular CuII?CuII distance in 1 is 5.640(7) Å. The EPR behaviour of 1 has been investigated at room temperature and at 77 K. The magnetic properties were measured in the temperature range 1.8-300 K.  相似文献   

6.
To complete the elucidation of the electrochemical properties of MnII-bis(terpyridine) complexes in CH3CN and evaluate the influence of the bulkiness of the terpy substituents, the oxidation processes of [MnII(L)2]2+ (L = terpy for 2,2′:6′,2″-terpyridine, pTol-terpy for 4′-(4-methylphenyl)-2,2′:6′,2″-terpyridine and tBu3-terpy for 4,4′,4″-tri-tert-butyl-2,2′:6′,2″-terpyridine) have been investigated in aqueous (1 M) CH3CN solution. In this medium, exhaustive oxidations at 1.10-1.20 V versus Ag/Ag+ release two electrons per molecule of initial complex and lead to clean dimerization processes with the quantitative formation of the oxo-bridged binuclear [Mn2IVO2(L)2(H2O)2]4+ complex for L = tBu3-terpy and of the tetranuclear [Mn4IVO5(L)4(H2O)2]6+ complexes for L = terpy and pTol-terpy. The formation of the tetranuclear complex with the tBu3-terpy derivative is prevented by the steric hindrance induced by the bulkiness of the tert-butyl groups, as confirmed by molecular mechanics calculations, as well as by their strong electron-donating properties. All these electrogenerated multinuclear complexes have been fully characterized in solution by UV-vis and electron paramagnetic resonance (EPR) spectroscopy. A markedly improved chemical synthesis of [Mn4IVO5(terpy)4(H2O)2]6+ is also reported.  相似文献   

7.
Ring coupled bimetallic derivatives (μ-η5:5-C5H4C5H4)[Nb(CO)4]2 and [μ-CH25-C5H4)2][M(CO)4]2, where M = Nb and Ta have been prepared. The molecular structures of the latter two compounds have been determined: , triclinic, , a = 8.028(2) Å, b = 11.414(1) Å, c = 12.711(2) Å, α = 75.020(8)°, β = 80.34(2)°, γ = 79.46(2)°, V = 1097.3(4) Å3, Z = 2, R(F) = 2.79%; [μ-CH25-C5H4)2][Ta(CO)4]2, triclinic, , a = 7.815(3) Å, b = 10.275(4) Å, c = 13.135(4) Å, α = 104.25(3)°, β = 100.26(4)°, γ = 96.86(3)°, V = 991.2(6) Å3, Z = 2, R(F) = 3.00%.  相似文献   

8.
A new ligand, 1-(pyridin-2-yl)-N-(pyridin-2-ylmethyl)-N-(thiophen-3-ylmethyl)methanamine, ThDPA, was synthesized, as a new example of an N3S donor. Cu(II) complexes of this ligand were isolated. When Cu(NO3)2 was used as the metal source, a homobinuclear complex with the formula [CuThDPA(NO3)2]2·H2O, 1, with two different types of nitro coordination was isolated. 1 crystallizes in the monoclinic P21/n space group with a = 15.193, b = 8.181, c = 32.827 Å, β = 103.3° and V = 3971.9 Å3. In the case of CuSO4 as the source of copper(II), uncommon sulfato-bridged structures were isolated. The homobinuclear complex crystallized in two different lattices, depending on the solvent evaporation rate. Compound 2, with the formula [CuThDPA(SO4)]2·3H2O, crystallizes with 3 water molecules per binuclear structure in the monoclinic space group P21/c with a = 10.143, b = 17.013, c = 11.793 Å, β = 97.18° and V = 2019.1 Å3, and 3, [CuThDPA(SO4)]2·4H2O, crystallizes with 4 water molecules per binuclear structure in the triclinic space group, with a = 9.2906, b = 10.7297, c = 12.7236 Å, α = 79.66, β = 72.18, γ = 67.1° and V = 1109.7 Å3.  相似文献   

9.
The syntheses and characterization of novel binuclear chromium (III) complexes of 1,4,8,11-tetraazacyclotetradecane (cyclam) are described. The complex [(cyclam)Cr(OH)]2Cl4 · 7H2O (1) crystallizes in the monoclinic space group C2/c with four binuclear formula units in a cell of dimensions a = 17.403 (2), b = 16.803 (3), c = 12.708 (2) Å, and β = 100.83 (1)°. The cation in 1 consists of di-μ-hydroxodichromium (III) units. The bridging OH groups lie on a twofold axis, which relates one end of the dimer to the other and gives rise to a rigorously planar Cr2O2 bridging unit. The Cr?Cr separation is 3.122 (1) Å and the average bridging Cr-O-Cr angle is 104.6 (4)°. The complex [(cyclam)Cr(SO4)]2 (ClO4) · H2O (5) crystallizes in the monoclinic space group P21/c with two binuclear formula units in a cell of dimensions a = 9.516 (2), b = 13.263 (3), c = 14.870 (3) Å, and β = 104.08 (3)°. This cation consists of bis-μ-sulfato-di-chromium (III) units, in which the two chromium centers are bridged by two bridging sulfate groups leading to an eight-membered {Cr-O-S-O}2 bridging framework. Both dimers exhibit antiferromagnetic interactions, with J = 27.7 cm−1 for complex 1 and J = 4.7 cm−1 for complex 5. The EPR spectrum of the complex 1 has been simulated, demonstrating that the spectrum almost entirely originates from the quintet state, while a few lines can be attributed as triplet and septet transitions.  相似文献   

10.
Enhanced electrochemical resolution of anodic processes is possible in the presence of [N(nBu)4][B(C6F5)4], 1, as supporting electrolyte over that obtained in the presence of [N(nBu)4][PF6]. By changing the anion of the supporting electrolyte to a salt having [B(C6F5)4], anions, electrochemical processes of especially cationic analytes can benefit. Thus, the redox chemistry of 0.5 mmol dm−3 solutions of [Ru2(μ-FcCOO)4·(CH3CH2OH)2][PF6], 2, Fc = ferrocenyl, in CH2Cl2/[N(nBu)4][B(C6F5)4] were found to involve four well-resolved ferrocenyl-based electrochemical reversible redox processes as well as reduction of RuIII-RuII. At 1.0 mmol dm−3 concentrations of 2, or in the presence of [N(nBu)4][PF6], the four ferrocenyl processes coalesced into only two waves as a result of (Fc+)?() ion paring. Seventeen of the possible 18 one-electron transfer processes of the biscadmium trisphthalocyaninato complex [Cd2{Pc(C6H13)8}3], 3, could be observed in THF/[N(nBu)4][B(C6F5)4], but the electrochemical window of CH2Cl2/[N(nBu)4][B(C6F5)4] only allowed detection of 15 of these processes. Although reduction processes were unaffected, THF solvation leading to species such as (3n+)(THF)x with 1 ? n ? 4 and x ? 1 as well as ion pair formation of the type (3n+)?() prevented good resolution of oxidation processes. The CH2Cl2/[N(nBu)4][B(C6F5)4] system also allowed detection of reversible one-electron transfer ferrocenyl (Fc/Fc+) and ruthenocenyl-based (Rc/Rc+) processes for both enol and keto isomers of the β-diketone FcCOCH2CORc, 4, Rc = ruthenocenyl. In CH3CN/[N(nBu)4][PF6], the ruthenocenyl moiety was oxidised to a RuIV species.  相似文献   

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