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Stable Mn2+, Cu2+ and Ln3+ complexes with cyclen-based ligands functionalized with picolinate pendant arms |
Tartalom: | http://real.mtak.hu/15689/ |
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Archívum: | MTA Könyvtár |
Gyűjtemény: |
Status = Published
Type = Article |
Cím: |
Stable Mn2+, Cu2+ and Ln3+ complexes with cyclen-based ligands functionalized with picolinate pendant arms
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Létrehozó: |
RodrĂguez-RodrĂguez, Aurora
Garda, ZoltaĚn
RuscsĂĄk, Erika
Esteban-GĂłmez, David
de Blas, AndrĂŠs
RodrĂguez-Blas, Teresa
Lima, LuĂs M. P.
Beyler, Maryline
Tripier, RaphaĂŤl
TircsĂł, Gyula
Platas-Iglesias, Carlos
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Kiadó: |
Royal Society of Chemistry
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Dátum: |
2015
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Téma: |
QD01 Analytical chemistry / analitikai kĂŠmia
QD02 Physical chemistry / fizikai kĂŠmia
QD03 Inorganic chemistry / szervetlen kĂŠmia
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Tartalmi leírás: |
In this work we present the results of the equilibrium, dissociation kinetics, DFT and X-ray crystallographic studies performed on the complexes of metal ions of biomedical importance (Mn2+, Cu2+ and Gd3+) formed with octadentate ligands based on a cyclen platform incorporating two picolinate pendant arms (dodpa2ď and Medodpa2ď). The stability constants of the complexes were accessed by multiple methods (pH-potentiometry, direct and competition UV-vis spectrophotometry and 1H-relaxometry). The stability constants of the complexes formed with dodpa2 and Medodpa2 do not differ significantly (e.g. log K[Mn(dodpa)]=17.40 vs log K[Mn(Medodpa)]=17.46, log K[Cu(dodpa)]=24.34-25.17 vs. log K[Cu(Medodpa)]=24.74 and log K[Gd(dodpa)]+ = 17.27 vs log K[Gd(Medodpa)]+=17.59), which indicates that the steric hindrance brought by the methyl groups has no significant effect on the stability of the complexes. The stability constants of the Mn2+ complexes formed with the cyclen dipicolinates were found to be greater by ca. 3 log K units than those determined for the complex of the cyclen monopicolinate (dompaď) which indicates that the second picolinate moiety attached to the backbone of the macrocycle is very likely coordinate to the Mn2+ ion. However, the stability of the [Cu(dodpa)] and [Cu(Medodpa)] complexes agrees well with the stability constant of [Cu(dompa)]+, in line with the hexadentate coordination around the metal ion observed in the X-ray structure of [Cu(Medodpa)]. The [Gd(dodpa)]+ and [Gd(Medodpa)]+ complexes display a fairly high kinetic inertness, as the rate constants of acid catalysed dissociation (k1=2.5(4)ď´10-3 and 8.3(4)ď´10-4 M-1s-1 for [Gd(dodpa)]+ and [Gd(Medodpa)]+, respectively) are smaller than the value reported for [Gd(do3a)] (k1=2.5ď´10 2 M-1s-1). The [Mn(dodpa)] complex was found to be more inert than [Mn(Medodpa)]. The results of the diffusion-ordered NMR spectroscopy (DOSY) and DFT calculations of diamagnetic [La(dodpa)]+ and [Lu(dodpa)]+ complexes indicate the formation of a trinuclear entity of the La complex in aqueous solution.
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Nyelv: |
magyar
magyar
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Típus: |
Article
NonPeerReviewed
info:eu-repo/semantics/article
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Formátum: |
text
text
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Azonosító: |
RodrĂguez-RodrĂguez, Aurora and Garda, ZoltaĚn and RuscsĂĄk, Erika and Esteban-GĂłmez, David and de Blas, AndrĂŠs and RodrĂguez-Blas, Teresa and Lima, LuĂs M. P. and Beyler, Maryline and Tripier, RaphaĂŤl and TircsĂł, Gyula and Platas-Iglesias, Carlos (2015) Stable Mn2+, Cu2+ and Ln3+ complexes with cyclen-based ligands functionalized with picolinate pendant arms. DALTON TRANSACTIONS, 44. pp. 5017-5031. ISSN 1477-9226
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Kapcsolat: |