1
|
Kot K, Oczko G, Puchalska M, Starynowicz P. Relationships between structural and spectroscopic properties of complexes of o-phenanthroline and 2,2′-bipyridine with lanthanide (Ln = Sm, Eu) thiocyanates. Polyhedron 2020. [DOI: 10.1016/j.poly.2020.114770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
2
|
Structural and spectroscopic studies of heavy lanthanide complexes with o-phenanthroline and isothiocyanate. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.114119] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
3
|
Kariaka NS, Kolotilov SV, Gawryszewska P, Kasprzycka E, Weselski M, Dyakonenko VV, Shishkina SV, Trush VA, Amirkhanov VM. Structures and Spectral and Magnetic Properties of a Series of Carbacylamidophosphate Pentanuclear Lanthanide(III) Hydroxo Complexes. Inorg Chem 2019; 58:14682-14692. [PMID: 31647223 DOI: 10.1021/acs.inorgchem.9b02354] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of pentanuclear lanthanide complexes Ln5L6(μ-L)4(μ3-OH)4(μ4-OH) (LnIII = Nd, Dy, Ho, Er, Yb; L- = dimethyl N-benzoylamidophosphate ion, [C6H5C(O)-N-P(O)(OCH3)2]-) was obtained by the reaction of sodium dimethyl N-benzoylamidophosphate with the corresponding lanthanide nitrates. The pentanuclear cores formed as a result of self-arrangement and their composition did not depend on the lanthanide ion. The complexes and sodium dimethyl N-benzoylamidophosphate have been characterized by single-crystal X-ray diffraction. The absorption spectra of the complexes were measured at 300 and 4 K. The dysprosium and ytterbium complexes exhibited weak emission in the visible and IR regions, respectively. Temperature dependences of magnetic susceptibility (χM) of the dysprosium, holmium, and erbium compounds were studied. It was found that χM vs T dependences were governed by the crystal field splitting effects with the Δ parameter being in the range 5-17 cm-1. Slow magnetic relaxation was found for the dysprosium complex by ac magnetic measurements, while no significant out-of-phase signals were detected for holmium and erbium complexes.
Collapse
Affiliation(s)
- Nataliia S Kariaka
- Taras Shevchenko National University of Kyiv , Department of Chemistry , 64/13, Volodymyrska Street , Kyiv 01601 , Ukraine
| | - Sergey V Kolotilov
- L. V. Pisarzhevskii Institute of Physical Chemistry of the National Academy of Sciences of Ukraine , Nauky ave. 31 , Kyiv 03028 , Ukraine
| | - Paula Gawryszewska
- Faculty of Chemistry University of Wroclaw 14 F. Joliot-Curie Str. , 50-383 Wroclaw , Poland
| | - Ewa Kasprzycka
- Faculty of Chemistry University of Wroclaw 14 F. Joliot-Curie Str. , 50-383 Wroclaw , Poland
| | - Marek Weselski
- Faculty of Chemistry University of Wroclaw 14 F. Joliot-Curie Str. , 50-383 Wroclaw , Poland
| | - Viktoriya V Dyakonenko
- STC "Institute for Single Crystals" , National Academy of Science of Ukraine , Nauky ave. 60 , 61001 Kharkiv , Ukraine
| | - Svitlana V Shishkina
- STC "Institute for Single Crystals" , National Academy of Science of Ukraine , Nauky ave. 60 , 61001 Kharkiv , Ukraine.,V. N. Karazin Kharkiv National University , 4 Svobody sq. , Kharkiv 61122 , Ukraine
| | - Victor A Trush
- Taras Shevchenko National University of Kyiv , Department of Chemistry , 64/13, Volodymyrska Street , Kyiv 01601 , Ukraine
| | - Vladimir M Amirkhanov
- Taras Shevchenko National University of Kyiv , Department of Chemistry , 64/13, Volodymyrska Street , Kyiv 01601 , Ukraine
| |
Collapse
|
4
|
Wang SY, Gao S, Dai JW, Shi YR, Dong X, Weng WZ, Zhou ZH. Carbonate and phosphite encaged in frameworks constructed from square lanthanum aminopolycarboxylates and sodium chloride. Dalton Trans 2019; 48:2959-2966. [PMID: 30741287 DOI: 10.1039/c8dt04940h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel additives of lanthanum aminopolycarboxylates with inorganic anions, Na12n[La(edta)L]4n·8nNaCl·4nH2O (1: L = HPO32-; 2: L = CO32-) and K12n[La(cdta)(CO3)]4n·35nH2O (3) (H4edta = ethylenediaminetetraacetic acid; H4cdta = cyclohexanediaminetetraacetic acid), were obtained in alkaline solution. Structural analyses reveal that 1 and 2 are isomorphous and contain interesting square structures. HPO32- (CO32-) was encaged in the constructed tetranuclear frameworks. Tetranuclear lanthanum ethylenediaminetetraacetate was further encaged in superstructures of sodium chloride. 3 has a similar square structure, in which edta is replaced by cdta. All complexes are fully characterized via elemental, FT-IR, NMR, thermogravimetric and structural analyses. Solution 13C NMR spectra show that 1 and 2 dissociate into mononuclear units in water. Interestingly, 2 possesses 3.7 Å diameter holes inside its crystals, which can adsorb a small amount of O2 or CO2 selectively. The amounts of O2 and CO2 adsorbed increase gradually from 0.32 and 0.38 mg g-1 at 0.4 bar to 15.90 and 10.54 mg g-1 at 29.9 bar, respectively.
Collapse
Affiliation(s)
- Si-Yuan Wang
- State Key Laboratory for Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | | | | | | | | | | | | |
Collapse
|
5
|
Janicki R, Mondry A. Structural and thermodynamic aspects of water–carbonate exchange equilibrium for MIII/IV–EDTA–carbonate systems. Inorg Chem Front 2019. [DOI: 10.1039/c8qi01062e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The carbonate anion readily displaces water molecules in the [Er(EDTA)(H2O)2]− complex and though it is mainly an entropy driven process, the formation of the [Er(EDTA)(CO3)]3– complex is additionally enthalpy stabilized.
Collapse
Affiliation(s)
- Rafał Janicki
- University of Wrocław
- Faculty of Chemistry
- 50-383 Wrocław
- Poland
| | - Anna Mondry
- University of Wrocław
- Faculty of Chemistry
- 50-383 Wrocław
- Poland
| |
Collapse
|
6
|
Pawlak-Jarosz N, Oczko G, Starynowicz P, Kot K. Relationship between the optical properties and the structure of a new complex: Nd(III)-isothiocyanate-2,2′-bipyridine. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2018.05.094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
7
|
Janicki R, Lindqvist-Reis P. Eu(iii) and Cm(iii) tetracarbonates – in the quest for the limiting species in solution. Dalton Trans 2018; 47:2393-2405. [DOI: 10.1039/c7dt04836j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The luminescence spectra of solids [C(NH2)3][Y:M(CO3)4]·2H2O (M = Eu, Cm) were used to establish the stoichiometry and stability of the limiting species of the aqueous Eu(iii) and Cm(iii) carbonate systems at different temperatures and in a broad range of ionic strengths.
Collapse
Affiliation(s)
- Rafał Janicki
- University of Wrocław
- Faculty of Chemistry
- 50-383 Wrocław
- Poland
| | - Patric Lindqvist-Reis
- Karlsruhe Institute of Technology
- Institute of Nuclear Waste Disposal
- 76021 Karlsruhe
- Germany
| |
Collapse
|
8
|
Firmino AD, Figueira F, Tomé JP, Paz FAA, Rocha J. Metal–Organic Frameworks assembled from tetraphosphonic ligands and lanthanides. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2017.08.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
9
|
Structure, stability and spectroscopic features of the neodymium(III) complex of the octadentate polypyridine ligand 6,6′-bis[bis(2-pyridylmethyl)aminomethyl]-2.2′-bipyridine. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2017.07.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
10
|
|
11
|
Firmino ADG, Mendes RF, Antunes MM, Barbosa PC, Vilela SMF, Valente AA, Figueiredo FML, Tomé JPC, Paz FAA. Robust Multifunctional Yttrium-Based Metal–Organic Frameworks with Breathing Effect. Inorg Chem 2017; 56:1193-1208. [DOI: 10.1021/acs.inorgchem.6b02199] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ana D. G. Firmino
- Department
of Chemistry, CICECO—Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
- Department
of Chemistry, QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Ricardo F. Mendes
- Department
of Chemistry, CICECO—Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Margarida M. Antunes
- Department
of Chemistry, CICECO—Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Paula C. Barbosa
- Department of Materials & Ceramic Engineering, CICECO − Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Sérgio M. F. Vilela
- Department
of Chemistry, CICECO—Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
- Department
of Chemistry, QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Anabela A. Valente
- Department
of Chemistry, CICECO—Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Filipe M. L. Figueiredo
- Department of Materials & Ceramic Engineering, CICECO − Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - João P. C. Tomé
- Department
of Chemistry, QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
- Centro
de Química Estrutural, Instituto Superior Técnico, University of Lisbon, Avenida Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Filipe A. Almeida Paz
- Department
of Chemistry, CICECO—Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| |
Collapse
|
12
|
Firmino AD, Mendes RF, Ananias D, Vilela SM, Carlos LD, Tomé JP, Rocha J, Almeida Paz FA. Microwave Synthesis of a photoluminescent Metal-Organic Framework based on a rigid tetraphosphonate linker. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2016.05.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
13
|
Janicki R, Gałęzowska J, Mondry A. Stoichiometry of lanthanide(iii) complexes with tripodal aminophosphonic ligands – a new solution to an old problem. Inorg Chem Front 2017. [DOI: 10.1039/c7qi00191f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The [Eu(NP2py)2]5− complex crystallized as a [C(NH2)3]5[Eu(NP2py)2]·12 compound. However, the formation of the [Ln(NP2py)2]5– species in aqueous solution starts at pH as high as 8.
Collapse
Affiliation(s)
- Rafał Janicki
- Faculty of Chemistry
- University of Wrocław
- 50-383 Wrocław
- Poland
| | - Joanna Gałęzowska
- Department of Inorganic Chemistry
- Wrocław Medical University
- 50-556 Wrocław
- Poland
| | - Anna Mondry
- Faculty of Chemistry
- University of Wrocław
- 50-383 Wrocław
- Poland
| |
Collapse
|
14
|
Cross JN, Macor JA, Bertke JA, Ferrier MG, Girolami GS, Kozimor SA, Maassen JR, Scott BL, Shuh DK, Stein BW, Stieber SCE. Comparing the 2,2′‐Biphenylenedithiophosphinate Binding of Americium with Neodymium and Europium. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201606367] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
| | - Joseph A. Macor
- Los Alamos National Laboratory Los Alamos NM 87545 USA
- University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | | | | | | | | | | | | | - David K. Shuh
- Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | | | - S. Chantal E. Stieber
- Los Alamos National Laboratory Los Alamos NM 87545 USA
- California State Polytechnic University Pomona CA 91768 USA
| |
Collapse
|
15
|
Cross JN, Macor JA, Bertke JA, Ferrier MG, Girolami GS, Kozimor SA, Maassen JR, Scott BL, Shuh DK, Stein BW, Stieber SCE. Comparing the 2,2′‐Biphenylenedithiophosphinate Binding of Americium with Neodymium and Europium. Angew Chem Int Ed Engl 2016; 55:12755-9. [DOI: 10.1002/anie.201606367] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Indexed: 11/06/2022]
Affiliation(s)
| | - Joseph A. Macor
- Los Alamos National Laboratory Los Alamos NM 87545 USA
- University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | | | | | | | | | | | | | - David K. Shuh
- Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | | | - S. Chantal E. Stieber
- Los Alamos National Laboratory Los Alamos NM 87545 USA
- California State Polytechnic University Pomona CA 91768 USA
| |
Collapse
|
16
|
Complexation studies of 177Lu with ethylenediaminetetramethylene phosphonic acid (EDTMP) as a bone pain palliative therapeutic radiopharmaceutical. Polyhedron 2016. [DOI: 10.1016/j.poly.2015.12.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
17
|
Janicki R, Kędziorski A, Mondry A. The first example of ab initio calculations of f–f transitions for the case of [Eu(DOTP)]5− complex—experiment versus theory. Phys Chem Chem Phys 2016; 18:27808-27817. [DOI: 10.1039/c6cp05284c] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Structure, IR and UV-vis-NIR spectra of the [Eu(DOTP)]5− complex in single crystals were studied experimentally. Ab initio calculations of the excited states of the [Eu(DOTP)]5− complex provide new insights into the interpretation of the observed f–f electronic transitions spectra.
Collapse
Affiliation(s)
- Rafał Janicki
- University of Wrocław
- Faculty of Chemistry
- 50-383 Wrocław
- Poland
| | - Andrzej Kędziorski
- Nicolaus Copernicus University
- Faculty of Physics
- Astronomy and Informatics
- Address Toruń
- Institute of Physics
| | - Anna Mondry
- University of Wrocław
- Faculty of Chemistry
- 50-383 Wrocław
- Poland
| |
Collapse
|
18
|
Holmberg RJ, Korobkov I, Murugesu M. Enchaining EDTA-chelated lanthanide molecular magnets into ordered 1D networks. RSC Adv 2016. [DOI: 10.1039/c6ra09831b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Extending molecular systems into chain networks is a unique method with which to orient magnetic molecules into well-ordered arrays along one dimension, and study their resulting properties.
Collapse
Affiliation(s)
- Rebecca J. Holmberg
- Department of Chemistry and Biomolecular Sciences
- University of Ottawa
- Ottawa
- Canada K1N 6N5
| | - Ilia Korobkov
- Department of Chemistry and Biomolecular Sciences
- University of Ottawa
- Ottawa
- Canada K1N 6N5
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences
- University of Ottawa
- Ottawa
- Canada K1N 6N5
| |
Collapse
|
19
|
Yotnoi B, Meundaeng N, Funfuenha W, Pattarawarapan M, Prior TJ, Rujiwatra A. Influence of secondary ligand on structures and topologies of lanthanide coordination polymers with 1,3,5-triazine-2,4,6-triamine hexaacetic acid. J COORD CHEM 2015. [DOI: 10.1080/00958972.2015.1100721] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Bunlawee Yotnoi
- Faculty of Science, Department of Chemistry, Chiang Mai University, Chiang Mai, Thailand
| | - Natthaya Meundaeng
- Faculty of Science, Department of Chemistry, Chiang Mai University, Chiang Mai, Thailand
| | - Watcharee Funfuenha
- Faculty of Science, Department of Chemistry, Chiang Mai University, Chiang Mai, Thailand
| | - Mookda Pattarawarapan
- Faculty of Science, Department of Chemistry, Chiang Mai University, Chiang Mai, Thailand
| | - Timothy J. Prior
- Department of Chemistry, University of Hull, Kingston upon Hull, UK
| | - Apinpus Rujiwatra
- Faculty of Science, Department of Chemistry, Chiang Mai University, Chiang Mai, Thailand
| |
Collapse
|
20
|
Janicki R, Mondry A. Thermodynamics of the hydration equilibrium derived from the luminescence spectra of the solid state for the case of the Eu–EDTA system. Phys Chem Chem Phys 2015; 17:29558-65. [DOI: 10.1039/c5cp02429c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Spectroscopic evidence of the hydration equilibrium for the case of the Eu–EDTA system.
Collapse
Affiliation(s)
- R. Janicki
- University of Wrocław
- Faculty of Chemistry
- F. Joliot-Curie 14
- 50-383 Wrocław
- Poland
| | - A. Mondry
- University of Wrocław
- Faculty of Chemistry
- F. Joliot-Curie 14
- 50-383 Wrocław
- Poland
| |
Collapse
|
21
|
Holmberg RJ, Ho LTA, Ungur L, Korobkov I, Chibotaru LF, Murugesu M. Observation of unusual slow-relaxation of the magnetisation in a Gd-EDTA chelate. Dalton Trans 2015; 44:20321-5. [DOI: 10.1039/c5dt04072h] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A Gadolinium EDTA chelate displays characteristic isotropic behaviour common of GdIII complexes under zero applied magnetic field, and anisotropic behaviour arising from dipolar coupling and weak spin–phonon coupling under an applied magnetic field.
Collapse
Affiliation(s)
- Rebecca J. Holmberg
- Department of Chemistry and Biomolecular Sciences
- University of Ottawa
- Ottawa
- Canada K1N 6N5
| | - Le Tuan Anh Ho
- Theory of Nanomaterials Group and INPAC - Institute for Nanoscale Physics and Chemistry
- Katholieke Universiteit Leuven
- 3001 Leuven
- Belgium
| | - Liviu Ungur
- Theory of Nanomaterials Group and INPAC - Institute for Nanoscale Physics and Chemistry
- Katholieke Universiteit Leuven
- 3001 Leuven
- Belgium
| | - Ilia Korobkov
- Department of Chemistry and Biomolecular Sciences
- University of Ottawa
- Ottawa
- Canada K1N 6N5
| | - Liviu F. Chibotaru
- Theory of Nanomaterials Group and INPAC - Institute for Nanoscale Physics and Chemistry
- Katholieke Universiteit Leuven
- 3001 Leuven
- Belgium
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences
- University of Ottawa
- Ottawa
- Canada K1N 6N5
| |
Collapse
|
22
|
Negri R, Baranyai Z, Tei L, Giovenzana GB, Platas-Iglesias C, Bényei AC, Bodnár J, Vágner A, Botta M. Lower denticity leading to higher stability: structural and solution studies of Ln(III)-OBETA complexes. Inorg Chem 2014; 53:12499-511. [PMID: 25387307 DOI: 10.1021/ic5020225] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The heptadentate ligand OBETA (2,2'-oxybis(ethylamine)-N,N,N',N'-tetraacetic acid) was reported to form complexes with Ln(3+) ions more stable than those formed by the octadentate and more popular congener EGTA (ethylene glycol O,O'-bis(ethylamine)-N,N,N',N'-tetraacetic acid). The structural features leading to this puzzling coordination paradox were investigated by X-ray diffraction, solution state NMR, molecular modeling, and relaxometric studies. The stability constant of Gd(OBETA) (log KGdL = 19.37, 0.1 M KCl) is 2 orders of magnitude higher than that of the higher denticity analogue Gd(EGTA) (log KGdL = 17.66, 0.1 M KCl). The half-lives (t1/2) for the dissociation reactions of Gd(OBETA) and Gd(EGTA) ([Cu(2+)]tot = 0.2 mM, [Cit(3-)]tot = 0.5 mM, [PO4(3-)]tot = 1.0 mM, and [CO3(2-)]tot = 25 mM at pH = 7.4 and 25 °C in 0.1 M KCl solution) are 6.8 and 0.63 h, respectively, reflecting the much higher inertness of Gd(OBETA) near physiological conditions. NMR studies and DFT calculations using the B3LYP functional and a large-core ECP indicate that the [Gd(OBETA)(H2O)2](-) complex most likely exists in solution as the Δ(λλ)(δδδδ)A/Λ(δδ)(λλλλ)A enantiomeric pair, with an activation free energy for the enantiomerization process of ∼40 kJ·mol(-1). The metal ion is nine-coordinate by seven donor atoms of the ligand and two inner-sphere water molecules. The X-ray crystal structure of [C(NH2)3]3[Lu(OBETA)(CO3)]·2H2O is in agreement with the predictions of DFT calculations, the two coordinated water molecules being replaced by a bidentate carbonate anion. The (1)H NMRD and (17)O NMR study revealed that the two inner-sphere water molecules in Gd(OBETA) are endowed with a relatively fast water exchange rate (kex(298) = 13 × 10(6) s(-1)). The higher thermodynamic stability and inertness of Ln(OBETA) complexes, peaking in the center of the 4f series, combined with the presence of two coordinated water molecules suggests that Gd(OBETA) is a promising paramagnetic probe for MRI applications.
Collapse
Affiliation(s)
- Roberto Negri
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale "A. Avogadro" , Largo Donegani 2/3, I-28100 Novara, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Janicki R, Mondry A. A new approach to determination of hydration equilibria constants for the case of [Er(EDTA)(H2O)n]−complexes. Phys Chem Chem Phys 2014; 16:26823-31. [DOI: 10.1039/c4cp04093g] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|