Coordination Behavior of 1,4-Disubstituted Cyclen Endowed with Phosphonate, Phosphonate Monoethylester, and H-Phosphinate Pendant Arms

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F19%3A10398863" target="_blank" >RIV/00216208:11310/19:10398863 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=TGvTnGUX_h" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=TGvTnGUX_h</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/molecules24183324" target="_blank" >10.3390/molecules24183324</a>

Result language

angličtina

Original language name

Coordination Behavior of 1,4-Disubstituted Cyclen Endowed with Phosphonate, Phosphonate Monoethylester, and H-Phosphinate Pendant Arms

Original language description

Three 1,4,7,10-tetraazacyclododecane-based ligands disubstituted in 1,4-positions with phosphonic acid, phosphonate monoethyl-ester, and H-phosphinic acid pendant arms, 1,4-H(4)do2p, 1,4-H(2)do2p(OEt), and 1,4-H(2)Bn(2)do2p(H), were synthesized and their coordination to selected metal ions, Mg(II), Ca(II), Mn(II), Zn(II), Cu(II), Eu(III), Gd(III), and Tb(III), was investigated. The solid-state structure of the phosphonate ligand, 1,4-H(4)do2p, was determined by single-crystal X-ray diffraction. Protonation constants of the ligands and stability constants of their complexes were obtained by potentiometry, and their values are comparable to those of previously studied analogous 1,7-disubstitued cyclen derivatives. The Gd(III) complex of 1,4-H(4)do2p is similar to 1 order of magnitude more stable than the Gd(III) complex of the 1,7-analogue, probably due to the disubstituted ethylenediamine-like structural motif in 1,4-H(4)do2p enabling more efficient wrapping of the metal ion. Stability of Gd(III)-1,4-H(2)do2p(OEt) and Gd(III)-H(2)Bn(2)do2p(H) complexes is low and the constants cannot be determined due to precipitation of the metal hydroxide. Protonations of the Cu(II), Zn(II), and Gd(III) complexes probably takes place on the coordinated phosphonate groups. Complexes of Mn(II) and alkali-earth metal ions are significantly less stable and are not formed in acidic solutions. Potential presence of water molecule(s) in the coordination spheres of the Mn(II) and Ln(III) complexes was studied by variable-temperature NMR experiments. The Mn(II) complexes of the ligands are not hydrated. The Gd(III)-1,4-H(4)do2p complex undergoes hydration equilibrium between mono- and bis-hydrated species. Presence of two-species equilibrium was confirmed by UV-Vis spectroscopy of the Eu(III)-1,4-H(4)do2p complex and hydration states were also determined by luminescence measurements of the Eu(III)/Tb(III)-1,4-H(4)do2p complexes.

Czech name

—

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

—

OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

<a href="/en/project/LTC17067" target="_blank" >LTC17067: Application of NMR relaxation and diffusion measurements to assess dynamics of complex molecular systems</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

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

Name of the periodical

Molecules

ISSN

1420-3049

e-ISSN

—

Volume of the periodical

24

Issue of the periodical within the volume

18

Country of publishing house

CH - SWITZERLAND

Number of pages

18

Pages from-to

3324

UT code for WoS article

000488830500116

EID of the result in the Scopus database

2-s2.0-85072181389