0000000001299847
AUTHOR
Javier Pitarch
Synthesis and Structural Characterization of a Cyclen-Derived Molecular Cage
Reaction of a tetrafunctionalized cyclen derivative containing four aldehyde groups with an appropriate diamine followed by reduction and demetalation highly efficiently affords a bis(cyclen)-derived molecular cage. Potentiometric investigations show that this compound forms dimetallic complexes with copper(II), with the two metal ions selectively coordinated to the cyclen units. X-ray crystallography indicates that these complexes could give rise to new cascade complexes after incorporation of anions between the metal centers.
Receptors for Nucleotides
Recognition and activation of nucleotides by polyammonium receptors constitute an important target in supramolecular chemistry since the very beginning of this field. Nucleotides have three components: (i) the polyphosphate chain, (ii) the sugar moiety, and (iii) the nucleobase, which permit their multipoint binding through attractions between opposite charges, hydrogen bonding, π-stacking, CH–π interactions, and so on. In this chapter, different receptors for nucleotides, most but not all of them consisting polyamines, are examined, focusing on their molecular structure that enables different binding modes to be operated. Also, a number of examples of nucleotide binding through metal compl…
In vitro and in vivo trypanosomicidal activity of pyrazole-containing macrocyclic and macrobicyclic polyamines: their action on acute and chronic phases of Chagas disease.
The in vitro and in vivo anti- Trypanosoma cruzi activity of the pyrazole-containing macrobicyclic polyamine 1 and N-methyl- and N-benzyl-substituted monocyclic polyamines 2 and 3 was studied. Activity against both the acute and chronic phases of Chagas disease was considered. The compounds were more active against the parasite and less toxic against Vero cells than the reference drug benznidazole, but 1 and 2 were especially effective, where cryptand 1 was the most active, particularly in the chronic phase. The activity results found for these compounds were complemented and discussed by considering their inhibitory effect on the iron superoxide dismutase enzyme of the parasite, the nature…
Zn(II)-coordination and fluorescence studies of a new polyazamacrocycle incorporating 1H-pyrazole and naphthalene units.
The synthesis and Zn(2+) coordination properties of a new macrocycle (L1) obtained by dipodal (2 + 2) condensation of the polyamine 3-(naphthalen-2-ylmethyl)pentane-1,5-diamine with 1H-pyrazole-3,5-dicarbaldehyde are reported. pH-metric studies show that L1 bears five measurable protonation steps in the 2.0-11.0 pH range. Fluorescence emission studies indicate that the removal of the first proton from the H(5)L1(5+) species leads to a significant decrease in the emission due to a photoinduced electron transfer process. Addition of Zn(2+) promotes a boat-like conformation that approaches both fluorophores and facilitates the formation of an excimer which reaches its highest emission for a 1 …
Tritopic phenanthroline and pyridine tail-tied aza-scorpiands
The synthesis of two new tritopic double-scorpiand receptors in which two equivalent 5-(2-aminoethyl)-2,5,8-triaza[9]-(2,6)-pyridinophane moieties have been linked with 2,6-dimethylpyridine (L1) or 2,9-dimethylphenanthroline (L2) units is reported for the first time. Their acid-base behaviour and Zn(2+) coordination chemistry have been studied by pH-metric titrations, molecular dynamic calculations, NMR, UV-Vis and steady-state fluorescence techniques. L1 and L2 behave, respectively, as hexaprotic and heptaprotic bases in the experimental conditions used (298.1 +/- 0.1 K, 0.15 mol dm(-3) NaCl, pH range under study 2.0-11.0). These ligands are able to form mono-, bi- and trinuclear Zn(2+) co…
CCDC 1431346: Experimental Crystal Structure Determination
Related Article: Alexander Ganß, Raquel Belda, Javier Pitarch, Richard Goddard, Enrique García-España, and Stefan Kubik|2015|Org.Lett.|17|5850|doi:10.1021/acs.orglett.5b03027
CCDC 1429442: Experimental Crystal Structure Determination
Related Article: Alexander Ganß, Raquel Belda, Javier Pitarch, Richard Goddard, Enrique García-España, and Stefan Kubik|2015|Org.Lett.|17|5850|doi:10.1021/acs.orglett.5b03027
CCDC 1431345: Experimental Crystal Structure Determination
Related Article: Alexander Ganß, Raquel Belda, Javier Pitarch, Richard Goddard, Enrique García-España, and Stefan Kubik|2015|Org.Lett.|17|5850|doi:10.1021/acs.orglett.5b03027