Now showing items 21-40 of 58

    • High relaxivity Mn2+-based MRI contrast agents 

      Regueiro-Figueroa, Martín; Rolla, Gabriele A.; Esteban-Gómez, David; Blas, Andrés de; Rodríguez-Blas, Teresa; Botta, Mauro; Platas-Iglesias, Carlos (Wiley, 2014-12-16)
      [Abstract] Stable Mn2+ mono- and binuclear complexes containing pentadentate 6,6′-((methylazanediyl)bis(methylene)) dipicolinic acid coordinating units give remarkably high relaxivities due to the presence of two inner-sphere ...
    • Stable Mn2+, Cu2+ and Ln3+ complexes with cyclen-based ligands functionalized with picolinate pendant arms 

      Rodríguez-Rodríguez, Aurora; Garda, Zoltán; Ruscsák, Erika; Esteban-Gómez, David; Blas, Andrés de; Rodríguez-Blas, Teresa; Lima, Luís M. P.; Beyler, Maryline; Tripier, Raphaël; Tircsó, Gyula; Platas-Iglesias, Carlos (Royal Society of Chemistry, 2015-01-20)
      [Abstract] In this study 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 (Mn 2+ , Cu 2+ and ...
    • Importance of outer-sphere and aggregation phenomena in the relaxation properties of phosphonated gadolinium complexes with potential applications as MRI contrast agents 

      Elhabiri, Mourad; Abada, Sabah; Sy, Mohamadou; Nonat, Aline; Choquet, Philippe; Esteban-Gómez, David; Cassino, Claudio; Platas-Iglesias, Carlos; Botta, Mauro; Charbonnière, Loïc J. (Wiley, 2015-04-10)
      [Abstract] A series composed of a tetra-, a tris- and a bisphosphonated ligand based on a pyridine scaffold (L4, L3 and L2, respectively) was studied within the frame of lanthanide (Ln) coordination. The stability constants ...
    • Gd3+-based magnetic resonance imaging contrast agent responsive to Zn2+ 

      Regueiro-Figueroa, Martín; Gündüz, Serhat; Patinec, Véronique; Logothetis, Nikos K.; Esteban-Gómez, David; Tripier, Raphaël; Angelovski, Goran; Platas-Iglesias, Carlos (American Chemical Society, 2015-10-15)
      [Abstract] We report the heteroditopic ligand H5L, which contains a DO3A unit for Gd3+ complexation connected to an NO2A moiety through a N-propylacetamide linker. The synthesis of the ligand followed a convergent route ...
    • Exceptionally inert lanthanide(III) PARACEST MRI contrast agents based on an 18-membered macrocyclic platform 

      Castro, Goretti; Regueiro-Figueroa, Martín; Esteban-Gómez, David; Bastida, Rufina; Macías, Alejandro; Pérez-Lourido, Paulo; Platas-Iglesias, Carlos; Valencia, Laura (Wiley, 2015-12-14)
      [Abstract] We report a macrocyclic ligand based on a 3,6,10,13-tetraaza-1,8(2,6)-dipyridinacyclotetradecaphane platform containing four hydroxyethyl pendant arms (L1) that forms extraordinary inert complexes with Ln3+ ions. ...
    • Approaching the kinetic inertness of macrocyclic gadolinium(III)-based MRI contrast agents with highly rigid open-chain derivatives 

      Tircsó, Gyula; Regueiro-Figueroa, Martín; Nagy, Viktória; Garda, Zoltán; Garai, Tamás; Kálmán, Ferenc Krisztián; Esteban-Gómez, David; Tóth, Éva; Platas-Iglesias, Carlos (Wiley, 2016-01-08)
      [Abstract] A highly rigid open-chain octadentate ligand (H4cddadpa) containing a diaminocylohexane unit to replace the ethylenediamine bridge of 6,6′-[(ethane-1,2 diylbis{(carboxymethyl)azanediyl})bis(methylene)] dipicolinic ...
    • [C–H⋯anion] interactions mediate the templation and anion binding properties of topologically non-trivial metal–organic structures in aqueous solutions 

      Bilbeisi, Rana A.; Prakasam, Thirumurugan; Lusi, Matteo; El-Khoury, Roberto; Platas-Iglesias, Carlos; Charbonnière, Loïc J.; Olsen, John-Carl; Elhabiri, Mourad; Trabolsi, Ali (Royal Society of Chemistry, 2016-02-12)
      [Abstract] Two synthetic approaches—temperature variation and anion templation—allowed for the selective formation of a [2]catenane ([2]C4+) or a trefoil knot (TK6+), or for the enhanced formation of a Solomon link (SL8+), ...
    • Synthesis and characterisation of bismacrocyclic DO3A-amide derivatives – an approach towards metal-responsive PARACEST agents 

      Cakic, Nevenka; Verbić, Tatjana Ž.; Jelić, Ratomir M.; Platas-Iglesias, Carlos; Angelovski, Goran (Royal Society of Chemistry, 2016-02-26)
      [Abstract] Three new bismacrocyclic Ln3+ chelates consisting of triamide derivatives of cyclen with glycine, methyl and tert-butyl substituents (L1–3, respectively) linked to an acyclic EGTA-derived calcium chelator were ...
    • Magnetic anisotropies in rhombic lanthanide(III) complexes do not conform to Bleaney’s theory 

      Castro, Goretti; Regueiro-Figueroa, Martín; Esteban-Gómez, David; Pérez-Lourido, Paulo; Platas-Iglesias, Carlos; Valencia, Laura (American Chemical Society, 2016-04-04)
      [Abstract] We report a complete set of magnetic susceptibilities of lanthanide complexes with a macrocyclic ligand based on a 3,6,10,13-tetraaza-1,8(2,6)-dipyridinacyclotetradecaphane platform containing four hydroxyethyl ...
    • Paramagnetic lanthanide chelates for multicontrast MRI 

      Cakic, Nevenka; Savic, Tanja; Stricker-Shaver, Janice; Truffault, Vincent; Platas-Iglesias, Carlos; Mirkes, Christian; Pohmann, Rolf; Scheffler, Klaus; Angelovski, Goran (Royal Society of Chemistry, 2016-06-02)
      [Abstract] The preparation of a paramagnetic chelator that serves as a platform for multicontrast MRI, and can be utilized either as a T1-weighted, paraCEST or 19F MRI contrast agent is reported. Its europium(III) complex ...
    • Stimuli-responsive metal-directed self-assembly of a ring-in-ring complex 

      Alvariño Bouza, Cristina; Platas-Iglesias, Carlos; Blanco, Victor; García, Marcos D.; Peinador, Carlos; Quintela López, José María (Royal Society of Chemistry, 2016-06-06)
      [Abstract] Concentration, temperature and/or solvent polarity control the speciation on the metal-directed self-assembly of a ditopic pyridyl ligand L with cis-protected Pd(II) metal centers. This results into a controllable ...
    • Room temperature molecular up conversion in solution 

      Nonat, Aline; Chan, Chi Fai; Liu, Tao; Platas-Iglesias, Carlos; Liu, Zhenyu; Wong, Wing-Tak; Wong, Wai-Kwok; Wong, Ka-Leung; Charbonnière, Loïc J. (Springer Nature, 2016-06-15)
      [Abstract] Up conversion is an Anti-Stokes luminescent process by which photons of low energy are piled up to generate light at a higher energy. Here we show that the addition of fluoride anions to a D2O solution of a ...
    • Sulphur-rich functionalized calix[4]arenes for selective complexation of Hg2+ over Cu2+, Zn2+ and Cd2+ 

      Bensenane, Bachir; Asfari, Zouhair; Platas-Iglesias, Carlos; Esteban-Gómez, David; Djafri, Fatiha; Elhabiri, Mourad; Charbonnière, Loïc J. (Royal Society of Chemistry, 2016-08-16)
      [Abstract] The syntheses of two new ligands based on a calix[4]arene scaffold in the cone conformation functionalized on the phenolic positions 1 and 3 by diethylthiophosphonates (L1) or tetra(tri)thioethyleneglycol (L2) ...
    • Transient versus static electron spin relaxation in Mn2+ complexes relevant as MRI contrast agents 

      Platas-Iglesias, Carlos; Esteban-Gómez, David; Helm, Lothar; Regueiro-Figueroa, Martín (American Chemical Society, 2016-08-18)
      [Abstract] The zero-field splitting (ZFS) parameters of the [Mn(EDTA)(H2O)]2–·2H2O and [Mn(MeNO2A)(H2O)]·2H2O systems were estimated by using DFT and ab initio CASSCF/NEVPT2 calculations (EDTA = 2,2′,2″,2‴-(ethane-1,2-di ...
    • Unexpected Changes in the Population of Coordination Isomers for the Lanthanide Ion Complexes of DOTMA–Tetraglycinate 

      Kumas, Cemile; Fernando, W. Shirangi; Zhao, Piyu; Regueiro-Figueroa, Martín; Kiefer, Garry E.; Martins, André F.; Platas-Iglesias, Carlos; Sherry, A. Dean (American Chemical Society, 2016-09-19)
      [Abstract] Lanthanide complexes with DOTA–tetraglycinate (DOTA-(gly)4) heavily favor the square antiprismatic (SAP) coordination isomer in aqueous solution, a structural feature that has made them useful as water-based ...
    • Water exchange rates and mechanisms in tetrahedral [Be(H2O)4]2+ and [Li(H2O)4]+ complexes using DFT methods and cluster‐continuum models 

      Regueiro-Figueroa, Martín; Esteban-Gómez, David; Pujales-Paradela, Rosa; Caneda‐Martínez, Laura; Blas, Andrés de; Platas-Iglesias, Carlos (Wiley, 2016-10-05)
      [Abstract] The water exchange reactions in aquated Li+ and Be2+ ions were investigated with density functional theory calculations performed using the [Li(H2O)4]+·14H2O and [Be(H2O)4]2+·8H2O systems and a cluster‐continuum ...
    • The relationship between NMR chemical shifts of thermally polarized and hyperpolarized 89Y complexes and their solution structures 

      Xing, Yixun; Jindal, Ashish K.; Regueiro-Figueroa, Martín; Le Fur, Mariane; Kervarec, Nelly; Zhao, Piyu; Kovacs, Zoltan; Valencia, Laura; Pérez-Lourido, Paulo; Tripier, Raphaël; Esteban-Gómez, David; Platas-Iglesias, Carlos; Sherry, A. Dean (Wiley, 2016-11-07)
      [Abstract] Recently developed dynamic nuclear polarization (DNP) technology offers the potential of increasing the NMR sensitivity of even rare nuclei for biological imaging applications. Hyperpolarized 89Y is an ideal ...
    • Developing the family of picolinate ligands for Mn2+ complexation 

      Forgács, Attila; Pujales-Paradela, Rosa; Regueiro-Figueroa, Martín; Valencia, Laura; Esteban-Gómez, David; Botta, Mauro; Platas-Iglesias, Carlos (Royal Society of Chemistry, 2016-12-22)
      [Abstract] We have reported here a series of ligands containing pentadentate 6,6′-(azanediylbis(methylene))dipicolinic acid units that differ in the substituent present at the amine nitrogen atom (acetate: H3DPAAA; phenyl: ...
    • 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, Raphaël; Tircsó, Gyula; Carniato, Fabio; Botta, Mauro; Platas-Iglesias, Carlos (Wiley, 2017-01-23)
      [Abstract] 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 ...
    • Ditopic receptors containing urea groups for solvent extraction of Cu(II) salts 

      Carreira-Barral, Israel; Mato-Iglesias, Marta; Blas, Andrés de; Platas-Iglesias, Carlos; Tasker, Peter A.; Esteban-Gómez, David (Royal Society of Chemistry, 2017-02-15)
      [Abstract] The ditopic receptor L3 [1-(2-((7-(4-(tert-butyl)benzyl)-1,4,7,10-tetraazacyclododecan-1-yl)methyl)phenyl)-3-(3-nitrophenyl)urea] containing a macrocyclic cyclen unit for Cu(II)-coordination and a urea moiety ...