Treballs Finals de Grau (TFG) - Química

URI permanent per a aquesta col·leccióhttps://hdl.handle.net/2445/48525

Treballs Finals del Grau de Química de la Facultat de Química de la Universitat de Barcelona.

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Optimization of the cross-linker and fluorophore chain length in liquid crystal material mechanoluminescence
(2026-01) Sans Iglesias, Júlia; Velasco Castrillo, Dolores
Currently, there are various anisotropic materials with singular behaviors, whose mechanical, electrical or optical properties vary when an external stimulus is applied in a different orientation. Within this group of materials, we find those called Smart Materials (SM). These, when an external stimulus is applied to them, are capable of triggering a response, that is, they give rise to reversible changes in their properties, often associated with memory effects. Due to their peculiarity and their potential applications, these materials are studied in depth. Our research has been based on the study of monodomain Liquid Single Crystal Elastomers (LSCEs) and on the analysis of the variation of their fluorescent response when an external mechanical force is applied to them. Furthermore, the effect of two different synthesis methods on the final optical properties possessed by the synthesized elastomers in each method has been compared. The static pool method proposed by our research group and the method reported by Küpfer and Finkelmann, which is based on polymerization in a rotating PTFE mould. The elastomers that have been synthesized are composed of different monomers, among them, a fluorophore based on a carbazole functionalized with an aliphatic chain with a terminal double bond which is responsible for the fluorescence emission and a cross-linking agent derived from a hydroquinone substituted in the para position with two identical aliphatic chains that links the polymer chains. In this research, elastomers have been generated by combining fluorophores and cross-linkers with different aliphatic chain lengths in order to study their influence on the emitted mechanoluminescence. The obtained results show that elastomers synthesized using the pool method do not exhibit fluorescence due to the quenching phenomenon of the fluorophore caused by its proximity to the mesogen. In contrast, elastomers synthesized using the centrifugation method trigger a mechanoluminescent response, since during the synthesis process, the centrifugal force induces an orientation of the monomers that prevents quenching. In addition, the use of cross-linkers with longer aliphatic chains, generates elastomers more readily. Finally, the synthesized elastomers have been characterized using three techniques, a mechanoluminescence measurement and the swelling-deswelling process, which is used to determine the cross-linking state based from the degree of anisotropic swelling in different solvents and differential scanning calorimetry analysis.
Synthesis of LHOIPs with sustainable divalent transition metals for energy storage applications
(2026-01) Collao Jiménez, Dafne; Fernández Renna, Ana Inés; Salgado Pizarro, Rebeca
As discussed throughout this work, this research stems from the current complex global situation. We are in a context marked by a heavy reliance on fossil fuels. This factor, combined with constant population growth and industrial demand, makes the transition to renewable energy an environmental urgency. Consequently, there is a critical need for materials capable of storing energy efficiently. This work is based on the synthesis of a series of hybrid perovskites using different divalent metals selected for this study. The structure of these perovskites consists of alternating inorganic layers between two hydrocarbon chains. These compounds are of particular interest because they exhibit a solid-solid phase change with high enthalpy values and minimal volume variations, which are essential characteristics for energy storage. The primary objective is to identify the metal that provides the perovskite with the best properties for heat storage. Therefore, once the synthesis was completed to obtain crystals with the desired metals, the corresponding characterisation studies were carried out. Following the analysis of the results, it was determined that the Zn samples show the highest enthalpy and specific heat values. This indicates a superior heat storage capacity and optimal thermal stability compared to the other metals studied. The Mn and Cu samples also showed very favourable results, although slightly lower than those of Zn. In contrast, the Fe samples showed lower storage capacity and presented difficulties during the synthesis process. Finally, the Ni and Mg samples were completely discarded due to their low stability, structural disorder, and poor reproducibility of the experimental measurements. In conclusion, Zn stands out as the most suitable metal for producing perovskites aimed at thermal energy storage.
Synthesis of luminescent Pt(II) compounds with emissions in the NIR region
(2026-01) Saurí Abellán, Paula; Rodríguez Raurell, Laura; Lázaro Palacios, Ariadna
This Bachelor’s Final Project focuses on the design, synthesis, and photophysical characterization of novel Pt(II) complexes, aiming to evaluate how the metal’s coordination environment modulates phosphorescent emission. These systems play a fundamental role in the development of emerging biomedical and optoelectronic technologies, positioning them at the forefront of current scientific research. The first stage of the project involved the synthesis and characterization of several organic ligands specifically designed for subsequent platinum cyclometallation. The formation of these new compounds was confirmed using 1H NMR and IR spectroscopy. Ultimately, two organometallic complexes with distinct ligand environments were successfully obtained, enabling a comparative analysis of their properties under various conditions. The photophysical study was structured into three main blocks: first, a baseline characterization was conducted using UV-Vis spectroscopy and various emission techniques, including fluorimetry, phophorescence lifetimes, and quantum yields. This was followed by an aggregation study induced by solvent mixtures at a fixed concentration. These experiments demonstrated that the ligand structure is determining factor in the self-assembly capacity of the complex. The results show that, in addition to the high sensitivity of these compounds to oxygen quenching, the choice of ligand is crucial for controlling Pt···Pt interactions, π-π stacking and other possible weak intermoecular contacts. It was confirmed that, under specific solvent and concentration conditions, it is possible to induce or inhibit excimer formation, opening the door to the rational design of materials with tunable emissive properties.
Supramolecular switchable multifunctional materials
(2026-01) Roset Verdaguer, Maurici; Aguilà Avilés, David
This work has explored the design, synthesis, and supramolecular assembly of Fe(II) coordination compounds with the aim of developing multifunctional materials combining spin-crossover (SCO) and photoactive properties. A sequential approach was employed, consisting of isolating first a SCO Fe(II) crystalline precursor and further adding a photoactive coligand. Three ligands were explored to synthesize the iron(II) complexes: a tridentate ligand H4L1 and two bidentate ligands H2L2 and H2L3. The ligand H4L1 was synthesised and fully characterised prior to its coordination to Fe(II). All isolated SCO precursor Fe(II) complexes, regardless of the ligand employed, exhibit spin-crossover behaviour. Two Fe(II) supramolecular materials based on H4L1 were successfully crystallised and structurally characterised in the presence of two photoactive coligands: 4,4’-azopyridine and 1,2-bis(4-pyridyl)ethylene. However, upon formation of the corresponding cocrystals, these systems were found to stabilise exclusively the high-spin (HS) state, reflecting the rigid coordination environment imposed by the tridentate ligand and the supramolecular packing. Additional photoactive coligands, including1,2-bis(2′-methyl-5′-(pyrid-4″-yl)thien-3′-yl)perfluorocyclopentene, 4-(phenylazo)benzoic acid and 2-(4-hydroxyphenylazo)benzoic acid, were also explored, although they did not form crystalline supramolecular materials suitable for structural characterisation. In parallel, Fe(II) complexes incorporating the bidentate ligands H2L2 and H2L3 were also explored. In these systems, three ligands are required to complete the octahedral coordination sphere, leading to a more flexible coordination environment that is expected to better accommodate SCO after the supramolecular organisation. These complexes, previously studied within the research group, were investigated for cocrystallization with photoactive ligands, despite the synthetic challenges encountered. Finally, an alternative strategy based on the incorporation of the oxalate anion was explored in order to introduce an inorganic component with intrinsic magnetic properties, potentially acting as a single-molecule magnet.
Coupling Vibrations and Excitations: Exploring Ground-to-Excited State Relationships in Titania
(2026-01) Solà Caticha, Alex; Morales García, Ángel; Recio Poo, Miguel
This work studies a plausible relationship between ground-state properties and excited-state ones of photoactive hydrated titania nanoclusters. The goal is to understand the effect of the hydration degree on the structural and vibrational properties and excitation energies of a series of (TiO2)16(H2O)n (n = 0, 1 ,2 ,3 ,4 ,5 ,6, 7 and 8) nanoclusters. This computational exploration involves classical molecular dynamics and time-dependent density functional theory calculations. The results reveal that hydration induces structural distortions reflected in the vibrational modes of the titania nanoclusters framework. These changes are introduced by hydroxyl groups derived from dissociative water interaction. The degree of hydration also influences the excited state properties, shifting the lowest excitation energies towards higher values. In addition, the temperature at which the dynamics are performed significantly affects both the vibrational modes and the evolution of the excited state energies with time. Overall, this study demonstrates that both hydration and temperature play decisive roles in defining excited-state transitions in titania nanoclusters. Shortly, by identifying the vibrational modes coupled to the first excitation energy, the present work provides insight into the interplay between structure, dynamics and electronic excitations in photoactive TiO2 nanosystems, offering valuable information for the rational design of efficient photocatalysts in aqueous environments.
Designing new organic materials to control magnetism using electric fields
(2026-01) Espigares Vidal, Laia; Ribas Ariño, Jordi
The development of magnetoelectric materials, where magnetic and electric properties are coupled, has recently attracted significant attention due to their promising technological applications. This work explores the electric-field control of magnetic exchange interactions in fully organic diradicals composed of two stable radicals (trioxotriangulene radicals) connected by a dipolar linker, where the magnetoelectric response is tuned by modifying the linker dipole moment. Two new linkers, dicyanobenzene and dicyanoquinoxaline, are compared with a previously investigated reference system, a difluorobenzene-linked diradical, using density functional theory calculations. All molecular structures are obtained from DFT-based geometry optimizations employing the PBE0 exchange–correlation functional together with the 6-311G(d,p) basis set as implemented in the Gaussian09 package. The results show that increasing the dipole moment enhances the coupling between the electric field and the molecule, leading to larger changes in the torsional angle θ and, consequently, in the exchange coupling J. Among the systems studied, the dicyanoquinoxaline-linked diradical exhibits the strongest response, particularly in the out-of-plane configuration, which provides smooth and stable magnetoelectric tuning. These findings identify dicyanoquinoxaline as a promising linker for achieving efficient electric-field control of magnetism in organic systems.
Development of BaTiO3-Based Photocatalysts for H2 Production
(2026-01) Díaz Moral, Sonia; Vendrell, Xavier; Serafin, Jaroslaw
The global rise in energy demand and the continuous increase in atmospheric CO2 emissions have underscored the urgent need to develop cleaner and more sustainable energy technologies. Among the different strategies under study, photocatalytic hydrogen production is especially attractive, as it enables the conversion of solar energy into a carbon-free fuel. Titanium dioxide (TiO2) is one of the most widely investigated photocatalysts owing to its stability, low cost, and non-toxicity. However, its practical efficiency remains limited by rapid electron–hole recombination and weak absorption in the visible region. In this work, we synthesized novel TiO2-based composites modified with ferroelectric BST perovskites (Ba1-xSrxTiO3), conductive MXene (Ti3C2Tx), and metallic co-catalysts (Cu). The samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV–vis diffuse reflectance spectroscopy, photoluminescence spectroscopy (PL), and Brunauer–Emmett–Teller (BET) surface area analysis to evaluate their structural, optical, and morphological properties. Photocatalytic tests revealed a clear enhancement in hydrogen photoproduction. While pure TiO2 generated around 0.5 mmol·g-1·h-1, the best-performing TiO2/BST/MXene/Cu composite reached values equal to ~30 mmol·g-1·h-1. This improvement can be attributed to the synergistic contribution of each component. BST helps to separate charges more efficiently thanks to the internal electric field within its ferroelectric structure, which reduces the chance of electron–hole recombination. At the same time, MXenes act as highly conductive pathways, facilitating efficient electron transfer to the metal co-catalyst sites. As a result, charge recombination is suppressed, leading to a significant increase in hydrogen evolution activity. Overall, the obtained results demonstrate that combining TiO2 with BST, MXene, and Cu metal co-catalysts is a highly effective strategy for enhancing photocatalytic performance and supports the development of renewable hydrogen technologies.
Study of the interaction of fluorescent dyes with several DNA structures
(2026-01) Estrella Casas, Bruna; Gargallo Gómez, Raimundo
This project studies the interaction of four cyanine organic dyes (ID1-ID4) with different DNA structures, including the double helix, the G-quadruplex and the i-motif. For the characterisation of these interactions, molecular spectroscopic techniques such as UV-visible absorption, fluorescence and circular dichroism were used together with high-performance liquid chromatography. UV-visible absorption provides relevant information on the aggregation of the dyes in aqueous solution, while fluorescence and circular dichroism allowed insight into the general modes of interaction of the ligands with the DNA structures. The results show that the behaviour of the dyes varies depending on the substituents, although all four ligands can form H-dimers, only ID1 and ID3 form other H-type aggregates, such as trimers or tetramers. Regarding DNA binding, ID1 and ID3 interact via an ordered π-π stacking with the terminal tetrads of Pu22T14T23, which is a parallel G-quadruplex, whereas ID2 and ID4 exhibit a disordered interaction due to steric hindrance from their substituents. In the case of the Py39wt i-motif, all ligands show a disordered interaction. Thermal denaturation measurements indicate that dyes ID3 and ID4 significantly stabilise Pu22T14T23, whereas no ligand stabilises the Py39wt sequence. HPLC analysis also confirms the formation of DNA:dye complexes and that this binding does not produce significant conformational changes in the DNA structure. In summary, this study demonstrates that ligands can stabilise non-canonical DNA structures, particularly G-quadruplexes, making them interesting for future studies on the selective detection of G-quadruplexes and for the development of new therapeutic strategies for diseases such as cancer
Development and business viability of Bio-based Phase Change Materials (BPCM) from vegetable oil for application in the construction sector
(2026-01) Vilà Rosas, Sofia; Giró Paloma, Jessica; Vera Rivera, David; Luque Jiménez, Jorge
Climate change and the high energy demand of buildings require scalable solutions that improve thermal comfort, while reducing emissions and waste. This project develops sustainable phase change materials (PCM) from vegetable oil streams and converts them into microencapsulated PCM (MPCM) using recycled polymer shells, enabling passive thermal energy storage in mortars. Laboratory work focused on characterising olive oil, refining the PCM phase through fatty acid fractionation to obtain clearer thermal transitions and producing MPCM powder by solvent evaporation in an oil in water system with recycled PMMA as shell material. Different fractionation routes were examined, such as dry fractionation, solvent crystallisation and urea complexation. Among them, urea complexation provided the most effective separation, enabling the selection of an unsaturated enriched fraction as the MPCM core. Thermal and morphological analyses confirmed microcapsule formation and partial retention of phase behaviour, while also identifying technical challenges such as agglomeration and porosity that must be adressed to improve effective latent heat losses. In parallel, the results were translated into a B2B business proposal through market and competitor assessment and the development of marketing, operational, legal and financial plans. The financial model was built directly from experimentally obtained material balances and shows that process optimisation is the main lever to reach profitability at pilot scale. Through the combined chemical and business approach, this study supports a circular pathway that valorises waste streams, reduces environmental impact, and enhances wellbeing by improving indoor comfort and energy efficiency in buildings
Application of Sustainable Chemical Technologies for Climate Change Adaptation and Their Economic Impact on the Agricultural Sector
(2026-01) Secco, Valentina; Reigada Sanz, Ramon; Luque Jiménez, Jorge; Molina Mansilla, Ricardo
Adverse climatic conditions and, especially water stress, increasingly affect Mediterranean crops as a consequence of climate change. As an innovative and sustainable solution, non-thermal atmospheric plasma (NTAP) is presented, as it improves seed properties while avoiding the use of harmful chemical products for the environment. Therefore, this work studies plasma and, specifically, the one generated by dielectric barrier discharge can transform the hydrophobic character into a hydrophilic one in alfalfa and wheat seeds, thereby improving their water-use efficiency. Combined with this experimental analysis, a business plan is developed to assess economic viability in the current agricultural market. Through various assays (water contact angle, germination tests, and water imbibition tests), it is established that the optimal plasma treatment time is short to intermediate (between 30 and 120 s). When combined with physicochemical characterization techniques (OES, ATR-FTIR, SEM), both the reactive species generated and those present on the seed surface are identified, demonstrating that this is a purely local and surface-based technique. Overall, the obtained responses confirm an increase in hydrophilicity and, consequently, an improvement in seed water absorption and germination. Based on the results obtained and the presented context, a B2B business model is proposed, in which plasma treatment is offered as a service. The company adopts a strategy of gradual market penetration in the agricultural sector with strong R&D activity, which entails very high initial costs. In order to penetrate the agricultural market during the first years of operation, the service price is adjusted, despite being well below the estimated cost required to cover expenses. After the analysis conducted, it can be concluded that the proposed technique is an efficient and sustainable solution for improving crop performance; however, the business study clarifies that the sector is not yet prepared to sustain the costs in relation to the benefits provided by the service.
Meso-tetra(4-fluorobenzoyl) porphyrin: synthesis, characterization and study of its applications as a visible-light photoredox catalyst
(2026-01) Fabra Soucheiron, José Román; Moyano i Baldoire, Albert
Visible-light photoredox catalysis has become a powerful tool in organic synthesis, with an increasing interest in the development of efficient organophotocatalysts that avoid the use of scarce and/or toxic transition metals. Among these, porphyrins have attracted attention due to their tunable photophysical and redox properties. Previous studies by our research group demonstrated that both the electronic nature and the position of substituents on the porphyrin framework play a crucial role in modulating these properties and have led to the identification of meso-tetra(4-fluorobenzoyl)porphyrin as a particularly promising candidate due to the great facility of reduction of its excited state. In this context, the aims of this Bachelor’s thesis were to achieve a detailed characterization of this porphyrin, to investigate its photophysical behavior, and to evaluate its applicability as a visible-light photoredox catalyst. The target porphyrin was fully characterized by NMR spectroscopy, including HSQC experiments, allowing complete signal assignment (1H and 13C). Its singlet and triplet excited-state lifetimes were also determined . The compound was then applied as a photocatalyst in the addition of alkyl radicals, generated from 4-isopropyl-substituted Hantzsch esters, to p-substituted β-nitrostyrenes under visible-light irradiation. The reactions afforded mixtures of Giese addition and of nitro substitution products, whose distribution depends both on the irradiation wavelength and on the electronic nature of the styrene substituent. These results can be accounted for by a reductive quenching photoredox cycle involving initial oxidation of the Hantzsch ester by the excited porphyrin. While control experiments revealed that catalyst-free reactions can occur at wavelengths below 500 nm through direct excitation of the Hantzsch ester, at longer wavelengths the presence of the porphyrin photocatalyst becomes essential.
Evaluation of Advanced Catalysts for Green Methanol Synthesis
(2026-01) Trigo, Nahuel Ignacio; Guilera Sala, Jordi; Magagnin, Cippora
Methanol is of significant interest for integrated hydrogen production systems, both for transportation fuels and industrial uses, due to the advantageous properties of methanol as a hydrogen carrier. On this context, green methanol has emerged as a promising liquid fuel capable of substantially reducing carbon emissions and supporting the transition of the transport sector toward carbon neutrality. While conventional Cu/ZnO/Al2O3 (CZA) catalysts have been widely employed in methanol production, recent advances such as Atomic Layer Deposition (ALD) offers innovative approaches to catalyst synthesis. Evaluating this fabrication method can yield valuable insights into enhancing catalytic performance and sustainability. This study explores the synthesis and performance of Cu/ZnO/Al2O3 catalysts for methanol synthesis, with a particular focus on minimizing CuO content and studying the effects of the addition of ZnO, assessing ALD as an alternative to traditional preparation techniques. The main objective of this project is to review the best alternative of CuO precursor to synthetize the catalyst using the wet impregnation method, and once determined, compare and assess the catalytic activity of methanol synthesis catalysts prepared via ALD and conventional impregnation method. Through laboratory-scale experiments, the study aims to identify the most effective synthesis method in terms of activity, selectivity, and long-term stability. Catalysts with a varying CuO content were prepared using wet impregnation and those catalysts containing ZnO were deposited using ALD methods. Samples were studied by common analytical techniques. The catalytic activity of catalysts was evaluated in methanol synthesis reactions conducted at temperatures between 200-300ºC. This research has determined that copper nitrate is the best option as a CuO precursor for synthesizing the catalyst using the wet impregnation method. Furthermore, it demonstrated the importance of the presence of ZnO in the catalyst, resulting in better methanol productivity compared to catalysts without ZnO. Finally, it was determined that catalysts impregnated with 10% wt of Cu0 performed better than the catalysts impregnated with 20% and 30% wt of Cu0, obtaining a methanol production of 26.5 mmol g-1 h-1 and a carbon conversion of 10.25%.
Combined use of hyperspectral imaging and chemometrics to investigate the development of zebrafish embryos
(2026-01) Pons Forrellat, Berta; Juan Capdevila, Anna de; Marsal Terés, Maria
Zebrafish (Danio rerio) is a widely used model organism in biological research due to its high genetic similarity to humans. The optical transparency of the embryos, easy accessibility and fast development are the characteristics that make zebrafish particularly suitable for developmental and biomedical research. This project will focus on the investigation of the lipid distribution during zebrafish embryonic development, specifically at the middle-epiboly stage. To achieve this goal, embryos were stained using two lipidic-selective fluorophores, Nile Red and Lipi-Green, and analysed using confocal fluorescence hyperspectral imaging. Initially, embryos were stained with a single fluorophore at a time to evaluate its specificity and distribution. Subsequently, both fluorophores were applied simultaneously to enable a combined analysis of lipid components across the different embryonic regions. Due to the large and complex nature of hyperspectral datasets, chemometric analysis based on Multivariate Curve Resolution – Alternating Least Squares (MCR-ALS) was applied to extract meaningful information, obtaining the pure spectral signatures and the spatial distribution of the different lipid components. The results showed that Nile Red stained the three main embryonic regions – the yolk, the yolk syncytial layer (YSL) and the embryonic cells –, exhibiting two distinct emission shifts associated with differences in lipid polarity of the components. In contrast, Lipi-Green labelled a single lipid component, present in specific parts of the three regions. Overall, this study demonstrates that the combination of fluorescence hyperspectral imaging and chemometric analysis is a powerful approach for characterizing chemical and morphological changes during zebrafish embryonic development.
Identification of cellular biomarkers induced by light sensitive chemicals in an in vitro model
(2026-01) Duc Aguirre, Soraya; Llunell Marí, Miquel; Mitjans Arnal, Montserrat; Maddaleno Jiménez, Adriana S.
This study aims to develop novel in vitro methodology, currently unavailable, to discriminate between photoirritant and photoallergic reactions induced by chemical compounds with established evidence of photoirritation and/or photoallergic activity. The proposed approach is based on the quantification of specific biomarkers release using ELISA. Analyzed biomarkers were the interleukin-6 (IL-6), interleukin-8 (IL-8), and matrix metalloproteinase-1 (MMP-1), which are known to play key roles in inflammatory and tissue-remodeling responses in the skin. To achieve this objective and to ensure the reliability of the selected biomarkers, two experimental human cell lines were employed and evaluated under irradiated and non-irradiated conditions. The HaCaT immortalized human keratinocyte cell line was used as a dermal model, while the THP-1 human monocytic cell line mimic cutaneous dendritic cells and the immune-related responses involved in photoirritation and photoallergic mechanisms. Five chemical compounds with well-known phototoxic reactions were analyzed: as photoirritant and photoallergic was used chlorpromazine (CPZ), as non-phototoxic lactic acid (LA), as photoallergic 6-methylcoumarin (6-MC) and ketoprofen (KP) and as photoirritant retinoic acid (RA). Prior to biomarker evaluation, cell viability was assessed using LDH release and MTT reduction assays in both cell lines following exposure to each compound in irradiated and non-irradiated conditions. These preliminary assays ensured the use of subtoxic concentrations in subsequent ELISA experiments to detect the levels of the biomarkers proposed, thereby preventing cytotoxicity-related interference and enabling an accurate interpretation of biomarker modulation. Results showed that MMP-1 does not appear to be a suitable biomarker for identifying or discriminating photoirritant or photoallergenic compounds in HaCaT cells, as no significant differences were observed between irradiated and non-irradiated conditions. In addition, no notable differences were detected in the secretion of IL-6 in HaCaT cells for any of the tested compounds, further limiting its usefulness as a discriminative biomarker under the experimental conditions employed. In the case of IL-8, results showed that IL-8 cannot be considered a reliable biomarker in THP-1 cells at low lactic acid concentrations within the tested range. Under irradiated conditions, these concentrations reduced the expression of IL-8, while under non-irradiated conditions, no significant differences were observed. Additionally, when attempting to perform the LDH cytotoxicity assay with the same compound in THP-1 cells, the assay could not be successfully executed because the acidic environment interfered with the method.
Synthesis of protected 1,3-diols and 1,2-diols via C–H activation processes
(2026-01) Mòdol Balanzat, Pep; Ariza Piquer, Xavier
This work investigates the synthesis of protected 1,3- and 1,2-diols through Rh(III)-catalysed C–H activation processes, focusing on the intramolecular cyclisation of hemiacetals of bishomoallylic alcohols and exploring a new approach using homoallylic alcohols. The study is framed within the ongoing research efforts in our research group, aimed at the development of novel and efficient synthetic methodologies to access 1,3-diol and 1,2-diol motifs. Given the recurrent presence of these structural units in natural products, pharmaceuticals, and other bioactive compounds, the development of efficient and stereoselective synthetic methodologies remains a fundamental challenge in organic chemistry. The synthetic strategy explored is based on the in situ formation of hemiacetals from different alcohols and propanal, a process that involves a hemiacetal formation equilibrium that is key for obtaining the desired compounds. This synthetic route avoids the use of prefunctionalised substrates and enables the direct formation of protected cis-1,3-diols and 1,2-diols through the generation of sixand five-membered cyclic intermediates. The influence of substrate structure, particularly the differences among various bishomoallylic alcohols, on reactivity, cyclisation efficiency, and stereochemical outcome has been studied, and for the first time within the research group, experiments using a primary homoallylic alcohol have been carried out. Hemiacetals of bishomoallylic alcohols exhibit a greater tendency to undergo cyclisation, which is attributed to their increased conformational flexibility, favouring hemiacetal formation and intramolecular attack on the π-allyl–Rh intermediate. Conformational analysis allows the observed diastereoselectivity to be rationalised, highlighting a preference for chair conformations in which the bulkier substituents occupy equatorial positions.
Determination of pyrethroids in commercial insecticidal and antiparasitic products using gas chromatography
(2026-01) Homs-Procházka Pedrosa, Martina; Santos Vicente, Francisco Javier
Pyrethroids are synthetic insecticides derived from pyrethrins, substances extracted from chrysanthemum flowers that affect the neurological functions of insects. These synthetic compounds were developed as a more effective and persistent alternative to their natural counterparts, resulting in substances that are increasingly toxic to insects and exhibit greater persistence in the environment. Due to their high efficacy and favorable properties, pyrethroids are widely used as pesticides across a broad range of applications. The type of pyrethroid and its concentration in biocidal products are strictly regulated, and governmental authorities promote the selection of compounds with higher efficacy and minimal potential risks. In this project, different methods for the detection and quantification of pyrethroids commercial insecticidal and antiparasitic products have been developed. The optimization and validation of an analytical procedure for the determination of these substances in various matrices were carried out with the aim of producing a practical laboratory guide for students of the Analytical Chemistry Laboratory. Specifically, four pyrethroids present in sprays, lotions, aerosols and antiparasitic collars were analyzed using gas chromatography with flame ionization detection (GC-FID). The sample preparation process was adapted according to the matrix’s nature, primarily employing liquid-liquid extractions and solvent dilution of the product to ensure adequate determination of the active compounds while minimizing the presence of interfering substances. Subsequently, appropriate chromatographic separations and quantification were performed for each pyrethroid detected in the products. The developed methods achieved extraction yields above 80% for liquid-liquid extraction and standard deviations below 15%. The method proposed for the determination of pyrethroids in aerosols by sample dilution did not allow the determination of cypermethrin in aerosols due to significant matrix effects. The developed determination methods allowed to prepare laboratory practice guides for students of the Analytical Chemistry Laboratory, using equipment available in the laboratory, for the determination of permethrin, tetramethrin and deltamethrin in different biocidal products.
Synthesis and characterization of Pd functionalized UiO-66 and UiO-67 MOFs for C-C Coupling reactions
(2025-06) Zapirain Closas, Naiara; Sanz Nebot, María Victoria; Szilágyi, Petra Agota
Metal-organic frameworks (MOFs) have emerged as versatile porous materials thanks to their tuneable structures and compositional diversity. These features have positioned MOFs as promising candidates for a range of applications, particularly as platforms for heterogeneous catalysts. Among these, their potential to stabilize isolated metal atoms has attracted growing attention, opening new avenues in the development of single-atom catalysts[1]. Previous work carried out within the group of Szilágyi has demonstrated the immobilization of nanoclusters and single atoms of Pd incorporated into UiO-66 type metal-organic frameworks and has tested the catalytic activity of these Pd-laden MOFs in reactions such as the thermal hydrogenation of CO2. It was of interest to look for a reaction that demonstrates the catalytic activity of Pd single atoms embedded in functionalized UiO-66, and to investigate how Pd is incorporated in UiO-67 with new linkers. In this work, new functionalized linkers have been synthesized and incorporated into UiO-66 and UiO-67 MOFs, followed by metalation of the frameworks with Pd. Characterization has been done to confirm the structure of the material, and to understand the speciation of the incorporated Pd. The catalytic performance of the Pd immobilized frameworks for Stille coupling reaction has been assessed and the preliminary results are outlined. Functionalized terephthalic acid-based linkers and BPDC have first been synthesized and integrated into the UiO-66 and UiO-67 topology following an established synthesis protocol[2]. Metalation of these modified MOFs was achieved through the incorporation and subsequent in-situ reduction of a Pd precursor, allowing the integration of neutral Pd atoms within the MOF pores. Comprehensive structural analysis was performed using techniques such as X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emett-Teller (BET) surface area measurements, scanning electron microscopy (SEM), and microwave plasma atomic emission spectroscopy (MP-AES), enabling insights into the distribution and chemical state of Pd. Advanced characterization confirmed that palladium was successfully incorporated into the MOFs in both UiO-66 and UiO-67 type MOFs. BET measurements show that UiO-67 type MOFs have much larger surface area due to the larger size of the linkers used. The catalytic performance of the synthesized UiO-66 type MOFs in the Stille coupling reaction has been examined and confirmed in this work, with the obtention of biphenyl using the synthesized MOFs as catalysts.
Phosphorus ligands with the 1,8-dimethylnaphthalene scaffold
(2025-06) Vila Gaja, Alda; Grabulosa, Arnald
In this TFG, the study of the synthesis of different unreported phosphorus ligands based on the 1,8-dimethylnapthalene core has been carried out focusing on synthetic efficiency. The first part focuses on the synthesis of 1,8-dimethylnaphthalene (5) from naphthalic anhydride (1) involving a variety of synthetic methods and experiments that resulted into an efficient synthesis of 5. This compound has been characterized to ensure its purity to be used for the preparation of a P-phenylphosphorinane (8).Taking advantage of the precursors prepared for the synthesis of 5, two unreported ligands have also been synthesized, which can open the door to other interesting ligands for homogeneous catalysis: a bisphosphinite ligand (6) and an eight-membered cyclic phosphonite ligand (7). Both ligands have been characterized, including the selenide of 7, which allowed the evaluation of its donor properties. In addition, preliminary complexation studies of 7 with palladium(II) and ruthenium(II) precursors have been performed.Finally, the challenging synthesis of a novel 6-membered ring phosphorus heterocycle from precursor 5, the P-phenylphosphorinane 8, has also been performed by cyclisation of dilithiated 5 with dichlorophenylphosphine. Numerous difficulties, modifications, drawbacks and uncertainties had to be faced but it seems that the desired compound has been finally obtained and will be purified in future studies.
Study and optimisation of an α-selective catalytic allylic benzylborylation using Morita-Baylis-Hillman adducts and organoboron pronucleophiles
(2025-06) Villegas Vaquero, Ainhoa; Companyó Montaner, Xavier
Asymmetric allylic alkylation (AAA) is a chemical reaction in which an allylic substrate undergoes substitution by a nucleophile in the presence of a chiral catalyst, leading to the stereoselective formation of a new carbon–carbon or carbon–heteroatom bond at the allylic position. AAA reactions have become one of the most powerful and versatile catalytic strategies for the stereoselective formation of such bonds. For several years, these reactions were predominantly catalysed by transition metals. However, from 2000, many fundamental catalytic processes began to be developed under organocatalytic conditions, including the catalytic AAA using Morita-Baylis–Hillman (MBH) adducts as electrophilic substrates. Since then, significant progress has been made in the development of AAA methodologies. However, most reported AAA reactions involving MBH adducts have focused on achieving γ-selective asymmetric alkylation. In contrast, α-alkylations have been less extensively explored. The main goal of this TFG is the study and optimisation of an α-selective asymmetric allylic benzylborylation using MBH fluorides or MBH carbonates and organoboron pronucleophiles activated via desilylation or deborylation. Building on the knowledge previously acquired by the research group to achieve γ-selective asymmetric allylic benzylborylation, the objective of this TFG is to switch this γ-selectivity to α-selectivity. The most innovative aspect of the process is the use of the leaving group (LG) as a catalytic reaction initiator. The homoallylic benzylborylated product obtained is a valuable intermediate due to the versatile reactivity of organoboron compounds, which can serve as building blocks for the synthesis of other complex organic compounds
Alginate nanoparticles as a novel drug delivery system for Alzheimer's disease treatment
(2025-06) Tanyà Rovira, Sergi; Ignés i Mullol, Jordi; Grijalvo Torrijo, Santiago
Nanotechnology has emerged as a promising approach for developing innovative treatments for neurodegenerative diseases such as AD. The limited effectiveness of current therapies is largely attributed to the poor ability of drugs to cross the BBB. Recent advancements in biocompatible NPs have led to the creation of drug delivery systems (DDS) that offer minimal toxicity, superior BBB penetration, and improved transport of drugs with low water solubility. In this work, the application of ALG NPs for the treatment of AD is considered, with a focus on antioxidant therapy. Using the emulsion method, NPs with optimized properties for brain drug delivery were successfully synthesized. Key formulation parameters were adjusted to achieve a highly biocompatible and stable system, with particle sizes averaging around 12 nm (close to the ideal size for effective BBB penetration). A key aspect of the research involved optimizing surface charge, as positively charged NPs exhibit higher uptake across the BBB. However, attempts to achieve this through surfactant or cationic polymer coatings presented challenges, including undesirable increases in particle size and polydispersity. Ferulic acid (FA), a phytochemical with potent antioxidant activity, was selected as a model drug. Its successful encapsulation and loading into the NPs were confirmed using HPLC, demonstrating the system’s effectiveness in drug incorporation. To enhance therapeutic specificity, the NPs were functionalized with mitochondrial-targeting ligands. Of the ligands tested, (3-carboxypropyl)-triphenylphosphonium bromide (TPP) showed the most promising results. In contrast, the synthetic dendrons “G1” and “G2” faced significant solubility limitations and resulted in low functionalization yields. The most efficient strategy for ligand attachment proved to be the pre-functionalization of ALG before NPs synthesis. Although further optimization and comprehensive biological evaluation are necessary, the findings of this study establish a solid foundation for future research in the development of targeted nanotherapeutics for neurodegenerative diseases like AD.

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