Metal exchange reactions between divalent metal ions and their dithiocarbamate complexes in dimethyl sulfoxide: a kinetic and mechanistic study

The kinetics and mechanism of metal exchange between NiII, CuII, ZnII, CdII, PbII and HgII and their dithiocarbamate complexes have been studied in dimethyl sulfoxide. Two pathways for ligand transfer are observed. The first involves dissociation of dithiocarbamate from the metal complex followed by substitution at the metal ion, while the second involves direct electrophilic attack by the metal ion on the dithiocarbamate complex. The relative importance of the pathways depends on the stability of the complex and the substitution lability and electrophilic character of the metal ion. The stability of the dithiocarbamate complexes in dimethyl sulfoxide is in the order Hg > Cu > Ni > Pb ≈ Cd > Zn.

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Metallothionein-protein interactions

BioMolecular Concepts ◽

10.1515/bmc-2012-0049 ◽

2013 ◽

Vol 4 (2) ◽

pp. 143-160 ◽

Cited By ~ 29

Author(s):

Sílvia Atrian ◽

Mercè Capdevila

Keyword(s):

Protein Interactions ◽

Stress Responses ◽

Metal Ion ◽

Physical Contact ◽

Metal Exchange ◽

Exchange Reactions ◽

Spongiform Encephalopathies ◽

Small Proteins ◽

Parkinson’S Diseases ◽

Wide Range

AbstractMetallothioneins (MTs) are a family of universal, small proteins, sharing a high cysteine content and an optimal capacity for metal ion coordination. They take part in a plethora of metal ion-related events (from detoxification to homeostasis, storage, and delivery), in a wide range of stress responses, and in different pathological processes (tumorigenesis, neurodegeneration, and inflammation). The information on both intracellular and extracellular interactions of MTs with other proteins is here comprehensively reviewed. In mammalian kidney, MT1/MT2 interact with megalin and related receptors, and with the transporter transthyretin. Most of the mammalian MT partners identified concern interactions with central nervous system (mainly brain) proteins, both through physical contact or metal exchange reactions. Physical interactions mainly involve neuronal secretion multimers. Regarding metal swap events, brain MT3 appears to control the metal ion load in peptides whose aggregation leads to neurodegenerative disorders, such as Aβ peptide, α-synuclein, and prion proteins (Alzheimer’s and Parkinson’s diseases, and spongiform encephalopathies, respectively). Interaction with ferritin and bovine serum albumin are also documented. The intercourse of MTs with zinc-dependent enzymes and transcription factors is capable to activate/deactivate them, thus conferring MTs the role of metabolic and gene expression regulators. As some of these proteins are involved in cell cycle and proliferation control (p53, nuclear factor κB, and PKCμ), they are considered in the context of oncogenesis and tumor progression. Only one non-mammalian MT interaction, involving Drosophila MtnA and MtnB major isoforms and peroxiredoxins, has been reported. The prospective use for biomedical applications of the MT-interaction information is finally discussed.

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The Interaction of Cobalt(II), Nickel(II), Copper(II) and Zinc(II) With Oxygen-Nitrogen Donor Macrocycles Immobilized on a Polystyrene Matrix

Australian Journal of Chemistry ◽

10.1071/ch9861071 ◽

1986 ◽

Vol 39 (7) ◽

pp. 1071 ◽

Cited By ~ 12

Author(s):

RS Paredes ◽

NS Valera ◽

LF Lindoy

Keyword(s):

Metal Ion ◽

Matrix Effects ◽

Aqueous Media ◽

Solvent Mixture ◽

Ion Binding ◽

Metal Exchange ◽

Metal Ion Binding ◽

Exchange Reactions ◽

Binding Properties ◽

Crosslinked Polystyrene

Five macrocyclic ligands incorporating O2N2 or O2N3 donor sets have been appended to 2% crosslinked polystyrene, and the metal-ion-binding properties of the resulting functionalized polymers towards CoII , NiII, CuII and ZnII have been investigated. Loading studies were undertaken in ethyl acetate/methanol (9 : 1), and, under similar conditions, the degree of loading was found to be metal-dependent. In addition, in some cases metal uptake was found to exceed that required for 1:1 complexation of metal to cyclic ligand . In the above solvent mixture, metal-exchange reactions were found to be relatively facile. However, attempts to leach metal ions from the loaded polymers with either acid or ammonia in aqueous media were less successful due to poor swelling of the polymer beads in such media. Matrix effects associated with the polystyrene backbone appear to be the cause of the significant modification in metal-ion-binding properties of the immobilized macrocycles relative to those of their detached analogues.

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Expanding the Ligand Classes Used for Mn(II) Complexation: Oxa-aza Macrocycles Make the Difference

Molecules ◽

10.3390/molecules26061524 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1524

Author(s):

Ferenc K. Kálmán ◽

Viktória Nagy ◽

Rocío Uzal-Varela ◽

Paulo Pérez-Lourido ◽

David Esteban-Gómez ◽

...

Keyword(s):

Water Molecule ◽

Metal Ion ◽

Macrocyclic Ligand ◽

Relaxation Dispersion ◽

Metal Exchange ◽

Relaxation Rates ◽

Exchange Reactions ◽

Biologically Relevant ◽

The Difference ◽

Nuclear Magnetic

We report two macrocyclic ligands based on a 1,7-diaza-12-crown-4 platform functionalized with acetate (tO2DO2A2−) or piperidineacetamide (tO2DO2AMPip) pendant arms and a detailed characterization of the corresponding Mn(II) complexes. The X−ray structure of [Mn(tO2DO2A)(H2O)]·2H2O shows that the metal ion is coordinated by six donor atoms of the macrocyclic ligand and one water molecule, to result in seven-coordination. The Cu(II) analogue presents a distorted octahedral coordination environment. The protonation constants of the ligands and the stability constants of the complexes formed with Mn(II) and other biologically relevant metal ions (Mg(II), Ca(II), Cu(II) and Zn(II)) were determined using potentiometric titrations (I = 0.15 M NaCl, T = 25 °C). The conditional stabilities of Mn(II) complexes at pH 7.4 are comparable to those reported for the cyclen-based tDO2A2− ligand. The dissociation of the Mn(II) chelates were investigated by evaluating the rate constants of metal exchange reactions with Cu(II) under acidic conditions (I = 0.15 M NaCl, T = 25 °C). Dissociation of the [Mn(tO2DO2A)(H2O)] complex occurs through both proton− and metal−assisted pathways, while the [Mn(tO2DO2AMPip)(H2O)] analogue dissociates through spontaneous and proton-assisted mechanisms. The Mn(II) complex of tO2DO2A2− is remarkably inert with respect to its dissociation, while the amide analogue is significantly more labile. The presence of a water molecule coordinated to Mn(II) imparts relatively high relaxivities to the complexes. The parameters determining this key property were investigated using 17O NMR (Nuclear Magnetic Resonance) transverse relaxation rates and 1H nuclear magnetic relaxation dispersion (NMRD) profiles.

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Stability constants of complexes of metal ions with peatsoil humic acids under non-acid-conditions

Bayero Journal of Pure and Applied Sciences ◽

10.4314/bajopas.v14i1.8 ◽

2021 ◽

Vol 14 (1) ◽

pp. 54-63

Author(s):

Yusuf Sabo ◽

W.L.O. Jimoh ◽

Isa Baba Koki ◽

Q.O. Sholadoye

Keyword(s):

Metal Ions ◽

Stability Constants ◽

Humic Acids ◽

Metal Ion ◽

Aqueous Media ◽

Computational Method ◽

Divalent Metal Ions ◽

Acid Condition ◽

Stability Constants Of Complexes ◽

The Stability

Stability constants of complexes of four divalent metal ions viz. Cu2+, Pb2+,Mg2+ and Cd2+ with humic acids (HA) were determined by potentiometric titration of humic acids with the corresponding salt of the divalent metals in aqueous media under non-acid-condition. The log K (logarithm of the stability constant) ranged from 1.0942 to 2.7471 for metal-humic acid complexes were determined using point-wise computational method. The order of stability constants were obtained as follows: Cu >Pb> Cd > Mg for metal -HA complexes respectively, indicating a higher degree of complexation with Cu metal ion.

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Fabrication of Thin Metal-Organic Framework MOF Films on Metal-Ion-crosslinked GO-modified Supports

MRS Advances ◽

10.1557/adv.2017.466 ◽

2017 ◽

Vol 2 (46) ◽

pp. 2497-2504 ◽

Cited By ~ 1

Author(s):

Julius Choi ◽

Hyuk Taek Kwon ◽

Hae-Kwon Jeong

Keyword(s):

Metal Ions ◽

Surface Properties ◽

Metal Ion ◽

Metal Organic Framework ◽

Gas Permeation ◽

Divalent Metal ◽

Divalent Metal Ions ◽

Zeolitic Imidazolate Framework ◽

Metal Organic ◽

The Stability

ABSTRACTThin films of metal-organic frameworks (MOFs) have shown promising for applications such as gas separation, gas storage, optoelectronics or sensing. However, synthesis of polycrystalline MOF films and membranes depends largely on the surface properties of supports, limiting the availability of common supports. It is, therefore, highly desirable to develop ways to modify the surface properties of common supports for the preferred heterogeneous nucleation of the MOFs. Here, we demonstrated that graphene-oxide (GO) can be exploited to readily modify the surface properties of common supports, thereby leading to well inter-grown polycrystalline MOF films. A prototypical zeolitic-imidazolate framework ZIF-8 was chosen as a model MOF system. The stabilization of GO layers with divalent metal ions was found a key step to synthesize well inter-grown ZIF-8 films. The effect of divalent metal ions on the stability of GO layers and the quality of the resulting ZIF-8 films were systematically investigated. Finally, the single gas permeation behaviors of the ZIF-8 films grown on GO-modified supports were tested.

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Metal exchange reactions between cadmium protoporphyrin and cobalt and zinc chlorides in acetonitrile and dimethyl sulfoxide

Russian Journal of Inorganic Chemistry ◽

10.1134/s0036023606010189 ◽

2006 ◽

Vol 51 (1) ◽

pp. 112-117 ◽

Cited By ~ 5

Author(s):

S. V. Zvezdina ◽

M. B. Berezin ◽

B. D. Berezin

Keyword(s):

Dimethyl Sulfoxide ◽

Metal Exchange ◽

Exchange Reactions

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Structure of the complexes of ethylenediphosphinetetraacetic acid in solution

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19850445 ◽

1985 ◽

Vol 50 (2) ◽

pp. 445-453 ◽

Cited By ~ 2

Author(s):

Jana Podlahová ◽

Josef Šilha ◽

Jaroslav Podlaha

Keyword(s):

Metal Ion ◽

Carboxyl Groups ◽

Complex Solution ◽

Square Planar ◽

Weak Complexes ◽

Carboxylic Groups ◽

Uv Visible ◽

The Stability ◽

Tetrahedral Complexes ◽

Free Carboxyl

Ethylenediphosphinetetraacetic acid is bonded to metal ions in aqueous solutions in four ways, depending on the type of metal ion: 1) through an ionic bond of the carboxylic groups to form weak complexes with a metal:ligand ratio of 1 : 1 (Ca(II), Mn(II), Zn(II), Pb(II), La(III)); 2) through type 1) bond with contributions from weak interaction with the phosphorus (Cd(II)); 3) through coordination of the ligand as a monodentate P-donor with the free carboxyl groups with formation of 2 : 1 and 1 : 1 complexes (Cu(I), Ag(I)); 4) through formation of square planar or, for Hg(II), tetrahedral complexes with a ratio of 1 : 2 with the ligand as a bidentate PP-donor with the free carboxyl groups (Fe(II), Co(II), Ni(II), Pd(II), Pt(II)). On acidification of the complex solution, the first two protons are bonded to the carboxyl groups. The behaviour during further protonation depends on the type of complex: in complexes of types 1) and 2) phosphorus is protonated and the complex dissociates; in complexes of types 3) and 4) the free carboxyl groups are protonated and the phosphorus-metal bond remains intact. The results are based on correlation of the stability constants, UV-visible, infrared, 1H and 31P NMR spectra and magnetic susceptibilities of the complexes in aqueous solution.

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