0000000000555748
AUTHOR
Andrea Liberato
Pb2+complexes of small-cavity azamacrocyclic ligands: thermodynamic and kinetic studies
The synthesis, acid-base behavior and Pb2+ coordination chemistry of the new aza-scorpiand like ligand 5-[2-(N-2-fluorenyl)ethylamino]-2,5,8-triaza[9]-2,6-pyridinophane (L1) have been studied by potentiometry, NMR and spectrofluorimetric titrations, and the results are compared with those obtained for the related compounds L2, lacking the fluorenyl group, and L3, the macrocycle lacking the pendant arm. The crystal structures obtained for complexes [PbL1][PbL1Cl](NO3)Cl2·4H2O (1) and [PbL3](ClO4)2 (2) reveal that the metal ion is located over the plane defined by the nitrogen atoms of the macrocyclic core due to its inability to accommodate the large Pb2+ ion in the macrocyclic cavity. For L…
Methylation as an effective way to generate SOD-activity in copper complexes of scorpiand-like azamacrocyclic receptors
Abstract Methylation of the secondary amine groups of a scorpiand-type ligand consisting of a pyridine spacer connected through methylene groups to a tris(2-aminomethyl) unit with the pendant arm further functionalised with a 3-pyridine unit leads to a ligand whose Cu(II) complex exhibits threefold enhanced SOD activity with respect to the non-methylated ligand. Potentiometric studies indicate the formation of [CuL] 2+ species with a stability three orders of magnitude lower than that formed with the related non-methylated ligand. Kinetic studies indicate that methylation of the secondary nitrogens causes a deceleration of both the complex formation and the acid-induced dissociation of the …
Coordination Chemistry of Cu2+ Complexes of Small N-Alkylated Tetra-azacyclophanes with SOD Activity
A new tetraaza-pyridinophane macrocycle (L1) N-alkylated with two isopropyl and one methyl groups symmetrically disposed has been prepared and its behavior compared with those of the unsubstituted pyridinophane (L3) and the related compound with three methyl groups (L2). The protonation studies show that, first, a proton binds to the central methylated amine group of L1, while, second protonation leads to a reorganization of the protons that are at this stage attached to the lateral isopropylated amines. The X-ray structure of [HL1]+ agrees with the UV–vis and NMR studies as well as with the results of DFT calculations. The stability of the Cu2+ complexes decreases on increasing the bulkine…
CCDC 1559249: Experimental Crystal Structure Determination
Related Article: Aida Nebot-Guinot, Andrea Liberato, M. Angeles Máñez, M. Paz Clares, Antonio Doménech, Javier Pitarch-Jarque, Alvaro Martínez-Camarena, Manuel G. Basallote, Enrique García-España|2018|Inorg.Chim.Acta|472|139|doi:10.1016/j.ica.2017.08.044
CCDC 1559236: Experimental Crystal Structure Determination
Related Article: Aida Nebot-Guinot, Andrea Liberato, M. Angeles Máñez, M. Paz Clares, Antonio Doménech, Javier Pitarch-Jarque, Alvaro Martínez-Camarena, Manuel G. Basallote, Enrique García-España|2018|Inorg.Chim.Acta|472|139|doi:10.1016/j.ica.2017.08.044
CCDC 1827335: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Andrea Liberato, Estefanía Delgado-Pinar, Andrés G. Algarra, Javier Pitarch-Jarque, José M. Llinares, M. Ángeles Mañez, Antonio Domenech-Carbó, Manuel G. Basallote, Enrique García-España|2018|Inorg.Chem.|57|10961|doi:10.1021/acs.inorgchem.8b01492
CCDC 1827337: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Andrea Liberato, Estefanía Delgado-Pinar, Andrés G. Algarra, Javier Pitarch-Jarque, José M. Llinares, M. Ángeles Mañez, Antonio Domenech-Carbó, Manuel G. Basallote, Enrique García-España|2018|Inorg.Chem.|57|10961|doi:10.1021/acs.inorgchem.8b01492
CCDC 1827336: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Andrea Liberato, Estefanía Delgado-Pinar, Andrés G. Algarra, Javier Pitarch-Jarque, José M. Llinares, M. Ángeles Mañez, Antonio Domenech-Carbó, Manuel G. Basallote, Enrique García-España|2018|Inorg.Chem.|57|10961|doi:10.1021/acs.inorgchem.8b01492