74199-09-0Relevant articles and documents
Picolinate-containing macrocyclic Mn2+ complexes as potential MRI contrast agents
Molnar, Eniko,Camus, Nathalie,Patinec, Veronique,Rolla, Gabriele A.,Botta, Mauro,Tircso, Gyula,Kalman, Ferenc K.,Fodor, Tamas,Tripier, Raphael,Platas-Iglesias, Carlos
, p. 5136 - 5149 (2014)
We report the synthesis of the ligand Hnompa (6-((1,4,7-triazacyclononan-1- yl)methyl)picolinic acid) and a detailed characterization of the Mn2+ complexes formed by this ligand and the related ligands Hdompa (6-((1,4,7,10-tetraazacyclododecan-1-yl)methyl)picolinic acid) and Htempa (6-((1,4,8,11-tetraazacyclotetradecan-1-yl)methyl)picolinic acid). These ligands form thermodynamically stable complexes in aqueous solution with stability constants of logKMnL = 10.28(1) (nompa), 14.48(1) (dompa), and 12.53(1) (tempa). A detailed study of the dissociation kinetics of these Mn 2+ complexes indicates that the decomplexation reaction at about neutral pH occurs mainly following a spontaneous dissociation mechanism. The X-ray structure of [Mn2(nompa)2(H2O) 2](ClO4)2 shows that the Mn2+ ion is seven-coordinate in the solid state, being directly bound to five donor atoms of the ligand, the oxygen atom of a coordinated water molecule and an oxygen atom of a neighboring nompa- ligand acting as a bridging bidentate carboxylate group (μ-η1-carboxylate). Nuclear magnetic relaxation dispersion (1H NMRD) profiles and 17O NMR chemical shifts and transverse relaxation rates of aqueous solutions of [Mn(nompa)]+ indicate that the Mn2+ ion is six-coordinate in solution by the pentadentate ligand and one inner-sphere water molecule. The analysis of the 1H NMRD and 17O NMR data provides a very high water exchange rate of the inner-sphere water molecule (kex 298 = 2.8 × 109 s-1) and an unusually high value of the 17O hyperfine coupling constant of the coordinated water molecule (AO/h = 73.3 ± 0.6 rad s-1). DFT calculations performed on the [Mn(nompa)(H2O)]+· 2H2O system (TPSSh model) provide a AO/h value in excellent agreement with the one obtained experimentally.
An octadentate bis(semicarbazone) macrocycle: A potential chelator for lead and bismuth radiopharmaceuticals
Blower, Philip J.,Bruchertseifer, Frank,Davey, Patrick R. W. J.,Lange, Jaclyn L.,Ma, Michelle T.,Morgenstern, Alfred,Paterson, Brett M.,White, Jonathan M.
, p. 14962 - 14974 (2020)
A variant of 1,4,7,10-tetraazacyclododecane (cyclen) bearing two semicarbazone pendant groups has been prepared. The octadentate ligand forms complexes with Bi3+ and Pb2+. X-ray crystallography showed that the neutral ligand provides an eight-coordinate environment for both metal ions and intermolecular hydrogen bond interactions have influenced the coordination environments of both complexes in the solid state. NMR spectroscopy revealed a fluxional environment for both complexes. The ligand was radiolabeled with the α-emitting radioactive isotope 213Bi3+, which is used in systemic targeted radiotherapy. The resulting complex was stable in serum for at least 90 min (two decay half-lives). The Pb2+ complex has reasonably fast kinetics of formation (t1/2 = 20 min) at 25 °C and pH 7.4. The Bi3+ and Pb2+ complexes show kinetic stability in 1.2 M HCl (half-lives of 214 min and 47 min, respectively). This is the first description of a macrocycle bearing semicarbazone pendant groups and its utility in coordinating main group metals, specifically those with radiotherapeutic potential.
TETRACYCLIC TETRAAMINES BY GLYOXAL-MACROCYCLIC TETRAAMINE CONDENSATION
Weisman, Gary R.,Ho, Suzzy C. H.,Johnson, Van
, p. 335 - 338 (1980)
A series of new tetracyclic tetraamines have been synthesized in good to moderate yield by glyoxal-macrocyclic tetraamine condensation.
A tris-macrocycle with proton sponge characteristics as efficient receptor for inorganic phosphate and nucleotide anions
Andrea Bencini,Biagini, Silvia,Giorgi, Claudia,Handell, Henri,Michel Le Baccon,Mariani, Palma,Paoletti, Piero,Paoli, Paola,Rossi, Patrizia,Tripier, Raphael,Valtancoli, Barbara
, p. 5610 - 5621 (2009)
Synthesis, characterisation and proton-sponge behaviour of a new linear constrained tris-macrocycle (L), containing three cyclen (cyclen = 1,4,7,10-tetraazacyclododecane) reinforced macrocycles connected by two 2,6-pyridinediylbis(methyl-ene) linkers, is reported. Protonated forms of L are efficient receptors for inorganic phosphate and nucleotide anions (ATP and ADP). The binding properties of L toward these substrates have been investigated in aqueous solution by means of Potentiometrie titrations, determining the stability constants of the adducts. The interaction mode was clarified by using 1H and 31P NMR measurements in aqueous solution and by means of molecular modelling calculations carried out on differently protonated species of L as well as on sev-eral nucleotide-receptor adducts. The stability of the adducts is mainly due to charge-charge and hydrogen bonding inter-actions between the polyphosphate chain of nucleotides and the ammonium groups of L.
Trans-Methylpyridine cyclen versus cross-bridged trans-methylpyridine cyclen. Synthesis, acid-base and metal complexation studies (metal = Co 2+, Cu2+, and Zn2+)
Bernier, Nicolas,Costa, Judite,Delgado, Rita,Felix, Vitor,Royal, Guy,Tripier, Raphael
, p. 4514 - 4526 (2011)
The synthesis of the cross-bridged cyclen CRpy2 {4,10-bis((pyridin-2-yl)methyl)-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane}, a constrained analogue of the previously described trans-methylpyridine cyclen Cpy2 is reported. The additional ethylene bridge confers to CRpy 2 proton-sponge type behaviour which was explored by NMR and potentiometric studies. Transition metal complexes have been synthesized (by complexation of both ligands with Co2+, Cu2+ and Zn 2+) and characterized in solution and in the solid state. The single crystal X-ray structures of [CoCpy2]2+, [CuCpy 2]2+ and [ZnCpy2]2+ complexes were determined. Stability constants of the complexes, including those of the cross-bridged derivative, were determined using potentiometric titration data and the kinetic inertness of the [CuCRpy2]2+ complex in an acidic medium (half-life values) was evaluated by spectrophotometry. The pre-organized structure of the cross-bridged ligand imposes an additional strain for the complexation leading to complexes with smaller thermodynamic stability in comparison with the related non-bridged ligand. The electrochemical study involving cyclic voltammetry underlines the importance of the ethylene cross-bridge on the redox properties of the transition metal complexes.
Preparation method of cyclen and intermediate thereof
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Paragraph 0100-0102; 0127-0130, (2021/07/08)
The invention discloses a preparation method of cyclen and an intermediate thereof, specifically a preparation method of a compound as shown in a formula 4. The method comprises the following step: in water, carrying out a reduction reaction as shown in the specification on a compound as shown in a formula 3 and hydrazine hydrate, wherein X is phosphoric acid or sulfuric acid, when X is phosphoric acid, n is 4/3, and when X is sulfuric acid, n is 2. The preparation method has the advantages of low cost, simple operation, easy purification of intermediates and products, high yield and purity, and suitableness for industrial production.
Definition of the Labile Capping Bond Effect in Lanthanide Complexes
Rodríguez-Rodríguez, Aurora,Regueiro-Figueroa, Martín,Esteban-Gómez, David,Rodríguez-Blas, Teresa,Patinec, Véronique,Tripier, Rapha?l,Tircsó, Gyula,Carniato, Fabio,Botta, Mauro,Platas-Iglesias, Carlos
supporting information, p. 1110 - 1117 (2017/02/05)
Two macrocyclic ligands containing a cyclen unit, a methyl group, a picolinate arm, and two acetate pendant arms attached to two nitrogen atoms of the macrocycle either in trans (1,7-H3Medo2 ampa = 2,2′-(7-((6-carboxypyridin-2-yl)methyl)-10-met
Incorporation of Cobalt-Cyclen Complexes into Templated Nanogels Results in Enhanced Activity
Jorge, Ana Rita,Chernobryva, Mariya,Rigby, Stephen E.J.,Watkinson, Michael,Resmini, Marina
, p. 3764 - 3774 (2016/03/08)
Recent advances in nanomaterials have identified nanogels as an excellent matrix for novel biomimetic catalysts using the molecular imprinting approach. Polymerisable Co-cyclen complexes with phosphonate and carbonate templates have been prepared, fully characterised and used to obtain nanogels that show high activity and turnover with low catalytic load, compared to the free complex, in the hydrolysis of 4-nitrophenyl phosphate, a nerve agent simulant. This work demonstrates that the chemical structure of the template has an impact on the coordination geometry and oxidation state of the metal centre in the polymerisable complex resulting in very significant changes in the catalytic properties of the polymeric matrix. Both pseudo-octahedral cobalt(III) and trigonal-bipyramidal cobalt(II) structures have been used for the synthesis of imprinted nanogels, and the catalytic data demonstrate that: i) the imprinted nanogels can be used in 15 % load and show turnover; ii) the structural differences in the polymeric matrices resulting from the imprinting approach with different templates are responsible for the molecular recognition capabilities and the catalytic activity. Nanogel P1, imprinted with the carbonate template, shows >50 % higher catalytic activity than P2 imprinted with the phosphonate.
A high-purity torus cane rather method for the preparation of
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Paragraph 0051-0063; 0087; 0090-0091, (2017/03/21)
The invention provides a preparation method of high-purity cyclen. The method comprises the following preparation paths. Cyclen obtained by the method of the invention has high purity. At the same time, the method greatly reduces the energy consumption and the power cost, and thereby reducing the raw material cost; the method greatly improves the reaction rate, reduces the catalyst amount and the reaction temperature, thereby shortening the consuming time of the process, and reducing the process cost; and the method greatly reduces the acid amount consumption, and thereby greatly reducing the equipment loss. The preparation method improves the production efficiency, and enables the product quality to reach more than 99.8%; hydrazine hydrate is used for replacing diethylenetriamine for a hydrolysis reaction, so the process is suitable for industrialized production. The method of the invention is environmentally friendly, is cost-saving, and is suitable for environment-friendly industrialization.
BIFUNCTIONAL do2pa DERIVATIVES, CHELATES WITH METALLIC CATIONS AND USE THEREOF
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Page/Page column 42, (2016/06/28)
The present invention relates to chelates resulting from the complexation of bifunctional do2pa derivatives ligands of formula (I), wherein the substituents R1, R1', R2, R2', R3, R3', Lsup