A combined NMR and DFT study of conformational dynamics in lanthanide complexes of macrocyclic DOTA-like ligands
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F17%3A10364260" target="_blank" >RIV/00216208:11310/17:10364260 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1039/c7cp05296k" target="_blank" >http://dx.doi.org/10.1039/c7cp05296k</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1039/c7cp05296k" target="_blank" >10.1039/c7cp05296k</a>
Alternative languages
Result language
angličtina
Original language name
A combined NMR and DFT study of conformational dynamics in lanthanide complexes of macrocyclic DOTA-like ligands
Original language description
The solution dynamics of the Eu(III) complexes of H(4)dota (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetracarboxylic acid) and H(5)do3ap (1,4,7,10-tetraazacyclododecane-4,7,10-tris(carboxymethyl)-1-methylphosphonic acid, bound in both monoprotonated and fully deprotonated forms) were investigated by using a combination of NMR measurements and DFT calculations. In solution, an equilibrium between the square antiprismatic (SAP) and twisted-square antiprismatic isomers (TSAP) of these complexes is present. These two isomers interconvert by rotation of the pendant arms or inversion of the cyclen chelate rings. 1D EXSY NMR spectra were used to determine these exchange rates with unprecedented accuracy. It was found that the two processes occur at different rates. Additional variable-temperature measurements allowed determination of the corresponding activation parameters for the two processes. DFT calculations were then used to obtain mechanistic information at the molecular level. The results show that the cyclen inversion pathway involves stepwise inversion of the four chelate rings formed upon metal ion coordination. However, the arm rotation process may operate through a synchronous rotation of the pendant arms or a stepwise mechanism depending on the system. A mixed cluster-continuum approach was required to improve the agreement between experimental and calculated activation parameters for the arm rotation process. The obtained results will aid the design of MRI contrast agents. Furthermore, the methodology developed in this work can be further applied for the investigation of other dynamic paramagnetic systems, e.g. peptides with Ln(III) probes or natively paramagnetic metalloproteins.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - 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
Result continuities
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)
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Physical Chemistry Chemical Physics
ISSN
1463-9076
e-ISSN
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Volume of the periodical
19
Issue of the periodical within the volume
39
Country of publishing house
GB - UNITED KINGDOM
Number of pages
10
Pages from-to
26662-26671
UT code for WoS article
000412763700019
EID of the result in the Scopus database
2-s2.0-85031328813