Metal Ammine Formation in Solution. XVII. Stability Constants of Copper(II) Methylamine and Diethylamine Complexes Obtained from Solubility Measurements with Gerhardtite, Cu(OH)1.5(NO3)0.5.

Ilcheva, Liliana; Bjerrum, Jannik; Jennische, Per; Hesse, Rolf; Sandström, M.

doi:10.3891/acta.chem.scand.30a-0343

Cited by 17 publications

(9 citation statements)

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“…This is in accord with its formation constant, which is low (7.60 log units) considering that it is a diamino ligand coordinating a single Cu 2 + ion. This value is comparable with the logb 2 value of 7.51 reported in the literature for methyl-A C H T U N G T R E N N U N G amine [11] and indicates that the two primary amines, separated by a chain of nine atoms, are not profiting from any chelate effect. The hydroxidecoordinated compound [L1H 2 Cu(OH)] + forms in an even lower quantity (< 15 %) and can be considered to be forming from [L1H 2 Cu] by deproA C H T U N G T R E N N U N G tonation of one of the water molecules that complete the coordination sphere of the Cu 2 + ion (pK a = 6.46).…”

Section: Resultssupporting

confidence: 77%

Single and Double pH‐Driven Cu²⁺ Translocation with Molecular Rearrangement in Alkyne‐Functionalized Polyamino Polyamido Ligands

Aurora

Boiocchi²,

Dacarro

et al. 2006

Chemistry A European J

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A new series of ligands, containing one (L1H(2)-L4H(2)) or two (L5H(4)-L6H(4)) 1,4,8,11-tetraaza-5,7-dione units and functionalized with a propargyl group on the C atom between the C=O moieties, has been synthesized. Protonation constants for the ligands and formation constants of their Cu(2+) complexes have been determined in water, and the coordination geometry of the complexes existing at various pH values has been investigated by coupled pH-metric and spectrophotometric titrations. Ligands capable of simple uptake of Cu(2+) with the formation of neutral, square-planar complexes containing the -2-charged diamino-diimido donor sets and ligands containing further coordinating groups (quinoline or pyridine) capable of single and double cation translocation have been investigated. The role of the substituents on the amino groups and the structural role played by the propargyl group have been examined as regards Cu(2+) complexation and translocation. In the double-translocating ligand L6H(4), when the two Cu(2+) ions move inside the diamino-diamido donor set, the slim propargyl group allows an unprecedented folding of the whole ligand with apical coordination of one pyridine to form a five-coordinate, square-pyramidal Cu(2+) ion. The crystal and molecular structures of this unusual [L6Cu(2)] complex have been determined by X-ray diffraction. Finally, oxidation of Cu(2+) to Cu(3+) has been studied by cyclic voltammetry in water, which revealed that the redox reaction occurs only when the copper cation is within the diamino-diimido compartment. Moreover, both functionalization of the primary amines with bulky substituents and apical coordination of Cu(2+) make access to the 3+ oxidation state more difficult and disrupt the reversibility of the electrochemical process.

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Section: Resultssupporting

confidence: 77%

Single and Double pH‐Driven Cu²⁺ Translocation with Molecular Rearrangement in Alkyne‐Functionalized Polyamino Polyamido Ligands

Aurora

Boiocchi²,

Dacarro

et al. 2006

Chemistry A European J

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“… a S1 = scenario 1: [NO 2 – ] = 2.2 × 10 –7 . M, [amine] = 1 mM, [Cl – ] = 1 M. b S3 = scenario 3: [NO 2 – ] = 1 M, [amine] = 1 mM, [Cl – ] = 1 mM. c Ref . d Ref . e Ref . f Ref . g The stated initial and relative rates will be an underestimate for the reasons discussed. …”

Section: Detailed Discussion and Resultsmentioning

confidence: 99%

Potential for the Formation of N-Nitrosamines during the Manufacture of Active Pharmaceutical Ingredients: An Assessment of the Risk Posed by Trace Nitrite in Water

Ashworth

Dirat

Teasdale

et al. 2020

Org. Process Res. Dev.

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Regulatory requests that marketing authorization holders for chemically synthesized active substances risk assess their medicines for the potential presence of N-nitrosamines have led to a renewed interest in amine nitrosation. We have used published mechanistic and kinetic studies of amine nitrosation to assess the risk that traces of nitrite in the water used during active pharmaceutical ingredient (API) manufacturing could give rise to significant levels of N-nitrosamines. We conclude that the levels of nitrite typically found in water used for API manufacture are very low (<0.01 mg/L) and will not give rise to significant levels of N-nitrosamines through reaction with basic secondary amines (pK a > 9.5) in the majority of cases. The use of less basic amines, elevated processing temperatures, or low pH conditions in combination with elevated levels of nitrite have the potential to generate levels of N-nitrosamines that could lead to significant quantities being present in the isolated API if the downstream processing does not provide an adequate purge. The kinetic models described may be used to risk assess specific situations or processes. For example, the addition of traces of dimethylamine to a nitrosation reaction is predicted to lead to the rapid, quantitative formation of N-nitroso dimethylamine. Simple tertiary alkylamines can nitrosate via a dealkylative process, which is significantly slower than secondary amine nitrosation. Therefore, they do not represent a risk of N-nitrosamine formation under conditions where there is no significant risk of secondary amine nitrosation.

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“…51,52 With the decrease of pH below 5, more of the L-cysteine on the surface of the AuNPs is and Cu 2+ -L-cysteine is 3.4 and 13.72 respectively. 66,67 The weak interaction between Cu 2+ and NH 2 group provides a potential breaking point for the removal of the AuNPs caps. Direct evidence of the removal of AuNPs was observed by TEM and SEM images.…”

Section: Stimuli Responsive Drug Releasementioning

confidence: 99%

Stimuli-responsive functionalized mesoporous silica nanoparticles for drug release in response to various biological stimuli

et al. 2014

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A silica-based mesoporous nanosphere (MSN) controlled-release drug delivery system has been synthesized and characterized. The system uses L-cysteine derivatized gold nanoparticles (AuNPs), bound to the MSNs using Cu 2+ as a bridging ion. The AuNPs serve as removable caps that hinder the release of drug molecules inside the amino functionalized MSN mesoporous framework. The modified MSNs themselves exhibit negligible cytotoxicity to living cells, as revealed using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The drug delivery system requires one of two biological stimuli to trigger drug release. These stimuli are either: low pH (pH < 5); or elevated levels of adenosine triphosphate (ATP) (concentration > 4 mM). The feasibility of biologically controlled release was demonstrated through the stimuli-induced removal of the AuNP caps over the MSN releasing the anticancer drug doxorubicin. We envisage that this MSN system could play a significant role in developing new generations of controlled-release delivery vehicles.

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Metal Ammine Formation in Solution. XVII. Stability Constants of Copper(II) Methylamine and Diethylamine Complexes Obtained from Solubility Measurements with Gerhardtite, Cu(OH)1.5(NO3)0.5.

Cited by 17 publications

References 0 publications

Single and Double pH‐Driven Cu²⁺ Translocation with Molecular Rearrangement in Alkyne‐Functionalized Polyamino Polyamido Ligands

Single and Double pH‐Driven Cu²⁺ Translocation with Molecular Rearrangement in Alkyne‐Functionalized Polyamino Polyamido Ligands

Potential for the Formation of N-Nitrosamines during the Manufacture of Active Pharmaceutical Ingredients: An Assessment of the Risk Posed by Trace Nitrite in Water

Stimuli-responsive functionalized mesoporous silica nanoparticles for drug release in response to various biological stimuli

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Metal Ammine Formation in Solution. XVII. Stability Constants of Copper(II) Methylamine and Diethylamine Complexes Obtained from Solubility Measurements with Gerhardtite, Cu(OH)1.5(NO3)0.5.

Cited by 17 publications

References 0 publications

Single and Double pH‐Driven Cu2+ Translocation with Molecular Rearrangement in Alkyne‐Functionalized Polyamino Polyamido Ligands

Single and Double pH‐Driven Cu2+ Translocation with Molecular Rearrangement in Alkyne‐Functionalized Polyamino Polyamido Ligands

Potential for the Formation of N-Nitrosamines during the Manufacture of Active Pharmaceutical Ingredients: An Assessment of the Risk Posed by Trace Nitrite in Water

Stimuli-responsive functionalized mesoporous silica nanoparticles for drug release in response to various biological stimuli

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Product

Resources

About

Single and Double pH‐Driven Cu²⁺ Translocation with Molecular Rearrangement in Alkyne‐Functionalized Polyamino Polyamido Ligands

Single and Double pH‐Driven Cu²⁺ Translocation with Molecular Rearrangement in Alkyne‐Functionalized Polyamino Polyamido Ligands