Complex Formation Constants for the Aqueous Copper(I)−Acetonitrile System by a Simple General Method

Kamau, Patrick; Rb, Jordan

doi:10.1021/ic001447b

Cited by 51 publications

(55 citation statements)

References 24 publications

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“…The binding isotherm is consistent with a 1:1 complex stoichiometry, and nonlinear least-squares fit over the entire spectral range yielded an apparent binding affinity of logK ϭ 6.88 Ϯ 0.05. The stability constants for the aqueous Cu(I)-CH 3 CN system have been accurately determined (35) and can be used in the nonlinear least-squares data analysis to account for competitive binding by CH 3 CN. With this data treatment, the apparent binding affinity of CTAP-1 was estimated to be logK ϭ 10.4 Ϯ 0.1.…”

Section: Microprobe X-ray Absorption Near-edge Structure (Microxanes)mentioning

confidence: 99%

Imaging of the intracellular topography of copper with a fluorescent sensor and by synchrotron x-ray fluorescence microscopy

Yang

McRae

Henary

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

361

286

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Copper is an essential micronutrient that plays a central role for a broad range of biological processes. Although there is compelling evidence that the intracellular milieu does not contain any free copper ions, the rapid kinetics of copper uptake and release suggests the presence of a labile intracellular copper pool. To elucidate the subcellular localization of this pool, we have synthesized and characterized a membrane-permeable, copper-selective fluorescent sensor (CTAP-1). Upon addition of Cu(I), the sensor exhibits a 4.6-fold emission enhancement and reaches a quantum yield of 14%. The sensor exhibits excellent selectivity toward Cu(I), and its emission response is not compromised by the presence of millimolar concentrations of Ca(II) or Mg(II) ions. Variable temperature dynamic NMR studies revealed a rapid Cu(I) self-exchange equilibrium with a low activation barrier of ⌬G ‡ ‫؍‬ 44 kJ⅐mol ؊1 and k obs ϳ 10 5 s ؊1 at room temperature. Mouse fibroblast cells (3T3) incubated with the sensor produced a copper-dependent perinuclear staining pattern, which colocalizes with the subcellular locations of mitochondria and the Golgi apparatus. To evaluate and confirm the sensor's copper-selectivity, we determined the subcellular topography of copper by synchrotron-based x-ray fluorescence microscopy. Furthermore, microprobe x-ray absorption measurements at various subcellular locations showed a near-edge feature that is characteristic for low-coordinate monovalent copper but does not resemble the published spectra for metallothionein or glutathione. The presented data provide a coherent picture with strong evidence for a kinetically labile copper pool, which is predominantly localized in the mitochondria and the Golgi apparatus.photoinduced electron transfer ͉ metal exchange kinetics ͉ dynamic NMR ͉ microprobe x-ray absorption near-edge spectroscopy

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Section: Microprobe X-ray Absorption Near-edge Structure (Microxanes)mentioning

confidence: 99%

Imaging of the intracellular topography of copper with a fluorescent sensor and by synchrotron x-ray fluorescence microscopy

Yang

McRae

Henary

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

361

286

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“…the observed reaction is not due This set of equilibria constants was chosen as they were measured at similar ionic strengths to those used in this study. The use of the stability constants reported by Jordan et al [41] does not affect the derived rate constants considerably. only to reaction (5) and (2) The rate constants are summed up in Table 3.…”

Section: Derivation Of K(cumentioning

confidence: 98%

“…Under the experimental conditions used here four Cu I complexes are present in the solution, [38][39][40][41] …”

Section: Derivation Of K(cumentioning

confidence: 99%

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Ligand Effects on the Chemical Activity of Copper(I) Complexes: Outer‐ and Inner‐Sphere Oxidation of Cu^IL

et al. 2007

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The effect of the ligands acetonitrile (AN), fumaric acid (H2fum) and 2,5,8,11‐tetramethyl‐2,5,8,11‐tetraazadodecane (L1) on the kinetics of oxidation of CuI complexes by [(cyclam)NiIII(SO4)2]– and [(NH3)5CoIIICl]2+ in aqueous solutions via an outer‐ and inner‐sphere mechanism, respectively, has been studied. The effects of the ligands on the electron self‐exchange rate constants have also been evaluated. All ligands studied stabilize CuI in aqueous solution but affect the redox potential of the CuII/IL couple differently. The ligands decrease the rate of the redox reactions and the electron self‐exchange rate constants. The results indicate that acetonitrile and alkenes should not be used as solvents for [CuIL]+‐catalyzed processes that involve redox steps. On the other hand, the results also suggest that [CuIL1]+ should be a good catalyst for such processes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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“…As the complex formation constants reported in literature are obtained at room temperature [9] it is needful to develop a method to estimate the Cu ? -ACN complex formation constant at the higher temperatures required to obtain high labeling yields.…”

Section: Introductionmentioning

confidence: 99%

Optimization of the labeling yield by determination of the Cu+–acetonitrile complex constant in Cu+-catalyzed nucleophilic exchange reactions in mixed solvent conditions

Eersels

Mertens

Herscheid

2010

J Radioanal Nucl Chem

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To apply the Cu? -assisted nucleophilic exchange based radioiodination of aromatic compounds for more lipophilic compounds the reaction is carried out in mixed solvent conditions. Due to its physicochemical properties acetonitrile is an attractive solvent. Although acetonitrile forms complexes with Cu ? decreasing the labeling yield. This article describes a method for the determination of the complex constant at labeling temperature based on a Lineweaver-Burk approach, relating the reaction rate constant and the concentration of precursor in presence of different amounts of acetonitrile. The method also allows to calculate the adjusted amount of copper salt in order to obtain the same high labeling yield as obtained in absence of acetonitrile.

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Complex Formation Constants for the Aqueous Copper(I)−Acetonitrile System by a Simple General Method

Cited by 51 publications

References 24 publications

Imaging of the intracellular topography of copper with a fluorescent sensor and by synchrotron x-ray fluorescence microscopy

Imaging of the intracellular topography of copper with a fluorescent sensor and by synchrotron x-ray fluorescence microscopy

Ligand Effects on the Chemical Activity of Copper(I) Complexes: Outer‐ and Inner‐Sphere Oxidation of Cu^IL

Optimization of the labeling yield by determination of the Cu+–acetonitrile complex constant in Cu+-catalyzed nucleophilic exchange reactions in mixed solvent conditions

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Complex Formation Constants for the Aqueous Copper(I)−Acetonitrile System by a Simple General Method

Cited by 51 publications

References 24 publications

Imaging of the intracellular topography of copper with a fluorescent sensor and by synchrotron x-ray fluorescence microscopy

Imaging of the intracellular topography of copper with a fluorescent sensor and by synchrotron x-ray fluorescence microscopy

Ligand Effects on the Chemical Activity of Copper(I) Complexes: Outer‐ and Inner‐Sphere Oxidation of CuIL

Optimization of the labeling yield by determination of the Cu+–acetonitrile complex constant in Cu+-catalyzed nucleophilic exchange reactions in mixed solvent conditions

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Product

Resources

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Ligand Effects on the Chemical Activity of Copper(I) Complexes: Outer‐ and Inner‐Sphere Oxidation of Cu^IL