4 research outputs found
Polyoxometalate-Based Hybrids with 3d- and 4f-Metal Complexes Bearing Multidentate Organic Ligands From Magnetoluminescent Molecular Species to Extended Frameworks with Sorption Ability
316 p.This dissertation explores the reactivity of polyoxometalates (POMs) - a well-known class of anionic metal-oxo clusters- towards 3d- or 4f-metal complexes of multidentate organic ligands. In the first part of this work, the influence of the pH on the polyoxomolybdate/{Cu(cyclam)}2+ (cyclam = 1,4,8,11-tetraazacyclotetradecane) synthetic system is evaluated. As a result, 4 different extended structures containing hepta- or octamolybdate anions have been synthesized, and chemical and structurally characterized. Moreover, their thermostructural behavior has been analyzed, which reveals the ability to undergo sequential thermally-triggered single-crystal-to-single-crystal transformations. Selective water and gas sorption properties have also been studied for anhydrous phases. Furthermore, the effect of the different aqueous reaction media on the assembly of Anderson-Evans/{Cu(DMC)}2+ (DMC = 1,8-dimethylcyclam) synthetic system has also been studied. The new 7 hybrid compounds with different dimensionalities have been characterized and their thermostructural behavior analyzed.The second part of this work includes the derivatization of mid-to-late 4f-metal-substituted Keggin-type POMs with compartmental organic ligands. The 10 novel molecular POMs have been chemical and structurally characterized. Some interesting properties of these clusters, such as photoluminescence or the slow relaxation of magnetization have also been analyzed and their solution behavior assessed by a combination of ESI-MS experiments and 1H-NMR spectroscopy
Consecutive single-crystal-to-single-crystal isomerization of novel octamolybdate anions within a microporous hybrid framework with robust water sorption properties
The 3D hybrid framework [{Cu(cyclam)}3(kMo8O27)]· 14H2O (1) (cyclam=1,4,8,11-tetraazacyclotetradecane) undergoes sequential single-crystal-to-singlecrystal transformations upon heating to afford two
different anhydrous phases (2 a and 3a). These transitions modify the framework dimensionality and enable
the isomerization of k-octamolybdate (k-Mo8) anions
into λ (2 a) and μ (3 a) forms through metal migration.
Hydration of 3 a involves condensation of one water
molecule to the cluster to afford the γ-Mo8 isomer in 4,
which dehydrates back into 3a through the 6a intermediate. In contrast, 2a reversibly hydrates to form 5,
exhibiting the same Mo8 cluster as that of 1. It is
remarkable that three of the Mo8 clusters (k, λ and μ)
are new and that up to three different microporous
phases can be isolated from 1 (2 a, 3a, and 6a). Water
vapor sorption analyses show high recyclability and the
highest uptake values for POM-based systems. The
isotherms display an abrupt step at low humidity level
desirable for humidity control devices or water harvesting in drylands.Funded by Eusko Jaurlaritza/Gobierno Vasco (EJ/GV, grants IT1722-22 and KK-2022/00045). E.R.B. thanks EJ/GV for her doctoral fellowship (PRE_2018_1_0143)
Gradu amaierako lanaren erronkak eta aukerak ezagutzaren gizarterako : Bilbo, Bizkaia Aretoa, 2014-V-19/20
Este primer Congreso Interuniversitario sobre el Trabajo Fin de Grado ha supuesto un encuentro y un espacio de reflexión e intercambio de diversas experiencias procedentes de los distintos grados y áreas de conocimiento de las universidades participantes. Esta diversidad se ha manifestado en las temáticas presentadas, que hacen referencia a: normativas de TFG, modalidades de TFG, número de créditos y del peso académico del TFG en cada plan de estudios, enfoques e instrumentos de evaluación, desarrollo de materiales para la elaboración del TFG, guÃas docentes, defensas del TFG, las plataformas de gestión integral desarrolladas en algunas universidades, etc. También se ha reflexionado sobre las diversas formas de la difusión de los TFG (Open Access, repositorios digitales propios de cada universidad) y la transferencia de conocimiento desde los grados a los distintos sectores de la sociedad, la cultura, economÃa, tecnologÃa, salud, innovación social, etc