1384099-48-2Relevant articles and documents
Picolinate-appended tacn complexes for bimodal imaging: Radiolabeling, relaxivity, photophysical and electrochemical studies
Beyler, Maryline,Bucher, Christophe,Faivre-Chauvet, Alain,Galland, Margaux,Gogolák, Réka Anna,Guillou, Amaury,Le Sa?c, Patricia,Maury, Olivier,Patinec, Véronique,Roux, Amandine,Tircsó, Gyula,Tripier, Rapha?l,Váradi, Balázs
, (2020)
Based on our previous works involving two 1,4,7-triazacyclononane (tacn)-based ligands Hno2py1pa (1-Picolinic acid-4,7-bis(pyridin-2-ylmethyl)-1,4,7-triazacyclononane) and Hno1pa (1-Picolinic acid-1,4,7-triazacyclononane), we report here the synthesis of analogues bearing picolinate-based π-conjugated ILCT (Intra-Ligand Charge Transfer) transition antenna (HL1, HL2), using regiospecific N-functionalization of the tacn skeleton and their related transition metal complexes (e.g. Cu2+, Zn2+ and Mn2+). Coordination properties as well as their photophysical and electrochemical properties were investigated in order to quantify the impact of such antenna on the luminescent or relaxometric properties of the complexes. The spectroscopic properties of the targeted ligands and metal complexes have been studied using UV–Vis absorption and fluorescence spectrocopies. While the zinc complex formed with HL1 possesses a moderate quantum yield of 5%, complexation of Cu2+ led to an extinction of the luminescence putatively attributed to a photo-induced electron transfer, as supported by spectroscopic and electrochemical evidences. The [Mn(L2)]+ complex is characterized by a fluorescence quantum yield close to 8% in CH2Cl2. The potential interest of such systems as bimodal probes has been assessed from radiolabeling experiments conducted on HL1 and 64Cu2+ as well as confocal microscopy analyses and from relaxometric studies carried out on the cationic [Mn(L2)]+ complex. These results showed that HL1 can be used for radiolabeling, with a radiochemical conversion of 40% in 15 min at 100 °C. Finally, the relaxivity values obtained for [Mn(L2)]+, r1p = 4.80 mM? 1·s? 1 and r2p = 8.72 mM? 1·s? 1, make the Mn(II) complex an ideal candidate as a probe for Magnetic Resonance Imaging.
Synthesis of an unsymmetrical N-functionalized triazacyclononane ligand and its Cu(II) complex
Roger, Mélissa,Patinec, Véronique,Tripier, Rapha?l,Triki, Smail,Poul, Nicolas Le,Mest, Yves Le
, p. 201 - 207 (2014/06/24)
The unsymmetrical 1,4-bis(2-aminophenyl)-7-(pyridin-2-ylmethyl)-1,4,7- triazacyclononane ligand (L3) has been prepared and characterized by NMR spectroscopy. The L3 ligand is based on the triazamacrocycle ring bearing one flexible 2-pyridylmethyl linked to the macrocycle group via the methyl group, and two rigid 2-aminophenyl pendant donor groups linked to the macrocycle via the aromatic carbon atoms. Reaction of this ligand with Cu(ClO4) 2·6H2O afforded the corresponding complex [Cu(L3)](ClO4)2·H2O (4) which was structurally characterized both in solid state and in solution. The crystal structure of 4 consists of a discrete monomeric [Cu(L3)]2+ in which the Cu(II) ion is six coordinated with three nitrogen atoms of the macrocycle ring, two of the aminophenyle and one of the pyridine appended functions. The triazacyclonane macrocycle ring is facially coordinated and the N-donor atoms of the three pendant groups (two aniline and one pyridine groups), are disposed in the same side of the basal macrocyclic ring, leading to a distorted and elongated CuN4N2 octahedron. UV-Vis spectroscopy of complex 4 in acetonitrile displays a d-d transition band at λ = 673 nm. The voltammetric studies show that the [Cu(L3)]2+ cation can be reduced quasi-reversibly and oxidized irreversibly, both process being monoelectronic.
Exo-diastereoisomer of 10-aryl-1,4,7-triazabicyclo[5.2.1]decane as intermediary in specific derivatisation of triazacyclononane
Roger, Mélissa,Patinec, Véronique,Bourgeois, Martine,Tripier, Rapha?l,Triki, Smail,Handel, Henri
experimental part, p. 5637 - 5643 (2012/09/22)
Reaction of triazacyclononane (tacn) and aromatic aldehydes leads to aminal adducts, which exhibit only the exo configuration. In these aminal compounds, secondary amine function possesses a higher reactivity towards electrophilic reactants than the two nitrogen atoms linked to aminal carbon, giving rise to the specific derivatisation of tacn by different functionalised groups. Study of this behaviour also permits the access to a ditopic tacn-cyclam bicyclic polyamine.
