NOTA Complexes with Copper(II) and Divalent Metal Ions: Kinetic and Thermodynamic Studies

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F18%3A10374431" target="_blank" >RIV/00216208:11310/18:10374431 - isvavai.cz</a>

Alternative codes found

RIV/00216224:14310/18:00103745

Result on the web

<a href="https://doi.org/10.1021/acs.inorgchem.7b02929" target="_blank" >https://doi.org/10.1021/acs.inorgchem.7b02929</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.inorgchem.7b02929" target="_blank" >10.1021/acs.inorgchem.7b02929</a>

Result language

angličtina

Original language name

NOTA Complexes with Copper(II) and Divalent Metal Ions: Kinetic and Thermodynamic Studies

Original language description

H(3)nota derivatives are among the most studied macrocyclic ligands and are widely used for metal ion binding in biology and medicine. Despite more than 40 years of chemical research on H(3)nota, the comprehensive study of its solution chemistry has been overlooked. Thus, the coordination behavior of H(3)nota with several divalent metal ions was studied in detail with respect to its application as a chelator for copper radioisotopes in medical imaging and therapy. In the solid-state structure of the free ligand in zwitterionic form, one proton is bound in the macrocyclic cavity through a strong intramolecular hydrogen-bond system supporting the high basicity of the ring amine groups (log K-a = 13.17). The high stability of the [Cu(nota)](-) complex (log K-ML = 23.33) results in quantitative complex formation, even at pH &lt;1.5. The ligand is moderately selective for Cu(II) over other metal ions (e.g., log K-ML(Zn) = 22.32 and log K-ML(Ni) = 19.24). This ligand forms a more stable complex with Mg(II) than with Ca(II) and forms surprisingly stable complexes with alkali-metal ions (stability order Li(I) &gt; Na(I) &gt; K(I)). Thus, H(3)nota shows high selectivity for small metal ions. The [Cu(nota)](-) complex is hexacoordinated at neutral pH, and the equatorial N2O2 interaction is strengthened by complex protonation. Detailed kinetic studies showed that the Cu(II) complex is formed quickly (millisecond time scale at c(Cu) approximate to 0.1 mM) through an out-of-cage intermediate. Conversely, conductivity measurements revealed that the Zn(II) complex is formed much more slowly than the Cu(II) complex. The Cu(II) complex has medium kinetic inertness (tau(1/2) 46 s; pH 0, 25 degrees C) and is less resistant to acid-assisted decomplexation than Cu(II) complexes with H(4)dota and H(4)teta. Surprisingly, [Cu(nota)](-) decomplexation is decelerated in the presence of Zn(II) ions due to the formation of a stable dinuclear complex. In conclusion, H(3)nota is a good carrier of copper radionuclides because the [Cu(nota)](-) complex is predominantly formed over complexes with common impurities in radiochemical formulations, Zn(II) and Ni(II), for thermodynamic and, primarily, for kinetic reasons. Furthermore, the in vivo stability of the [Cu(nota)](-) complex may be increased due to the formation of dinuclear complexes when it interacts with biometals.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Inorganic Chemistry

ISSN

0020-1669

e-ISSN

—

Volume of the periodical

57

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

12

Pages from-to

3061-3072

UT code for WoS article

000428219500016

EID of the result in the Scopus database

2-s2.0-85044177736