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

Kód výsledku v 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>

Nalezeny alternativní kódy

RIV/00216224:14310/18:00103745

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Inorganic Chemistry

ISSN

0020-1669

e-ISSN

—

Svazek periodika

57

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

3061-3072

Kód UT WoS článku

000428219500016

EID výsledku v databázi Scopus

2-s2.0-85044177736