Química (TFG)http://hdl.handle.net/10256/102322025-08-07T22:20:31Z2025-08-07T22:20:31ZOptimització de sistemes basats en nanopartícules de sílice per a la catàlisi heterogènia d’acoblament d’alcoholsLinillos Morgado, Ruthhttp://hdl.handle.net/10256/266742025-04-10T08:08:41Z2025-02-01T00:00:00ZOptimització de sistemes basats en nanopartícules de sílice per a la catàlisi heterogènia d’acoblament d’alcohols
Linillos Morgado, Ruth
In this final degree project, ruthenium complexes based on polypyridyl and dmso ligands have
been synthesized and characterized, with the aim of evaluating their catalytic activity in the
coupling of alcohols and the possibility of anchoring silica nanoparticles in these types of
complexes in order to optimize the system.
These compounds have been obtained from a first synthesis of the compound [RuCl2(dmso)4,
[1], from the reagent RuCl3·3H2O and dimethylsulfoxide at reflux. Once this complex has been
obtained, a second synthesis is carried out where the 2,2':6',6"-terpyridine ligand is coordinated
to the compound [1] in chloroform at 80oC, to end up forming cis-[RuCl2(terpy)(dmso), [2].
In order to study and characterize the properties of the synthesized compounds, spectroscopic
(NMR, UV-vis), spectrometric (ESI-MS) and electrochemical (cyclic voltammetry) techniques have
been used.
On the other hand, in this work, studies have been carried out focused on the incorporation of
the compounds into different silica materials (ST, LUS-TMA o-Ph-ST and Ph@LUS), some of them,
of the nanoparticle type, with the aim of making the catalytic system more efficient. As in the
previous study, spectroscopic (NMR, UV-vis), spectrometric (ESI-MS) and electrochemical (cyclic
voltammetry) techniques have been used to to characterize the new materials generated.
In addition, the catalytic efficiency of the complexes has been evaluated in the coupling of benzyl
alcohol and 1-phenylethanol in homogeneous phase, using several bases (potassium hydroxide,
potassium carbonate, piperidine and sodium methoxide) to improve selectivity and conversion.
Of these bases, the most suitable has been sodium methoxide. Additionally, the coupling product
has been quantified by gas chromatography using biphenyl as an internal standard, and the
percentage of conversion and selectivity of the different complexes have been calculated to be
able to compare the catalytic activity of the complexes in catalysis. The catalytic activity of the
heterogeneous systems obtained from anchoring the catalysts on silica-type supports has also
been studied, but the activity obtained has been low. At the end of the work, future strategies
are proposed to improve the efficiency of heterogeneous catalysts
2025-02-01T00:00:00ZEstudi de l’aromaticitat en l’estat singlet i triplet de compostos de bifenilè fusionats amb anells de sis membresVidal Sabench, Mariahttp://hdl.handle.net/10256/262662025-02-03T09:52:12Z2024-07-01T00:00:00ZEstudi de l’aromaticitat en l’estat singlet i triplet de compostos de bifenilè fusionats amb anells de sis membres
Vidal Sabench, Maria
π-Conjugated compounds formed by fused cycles with 4n+2 and 4n π electrons are interesting
for understanding the limits of aromaticity and antiaromaticity. These compounds in the ground
state exhibit intermediate properties between aromatic and antiaromatic systems. However,
their behaviour in the triplet state is not fully understood.
This study explores the rules of aromaticity, specifically Hückel’s and Baird’s rules, along with
Clar's π-sextet theory. The research combines these rules to investigate the triplet state energy
of 25 molecules, which are composed of biphenylene compounds fused with six-membered
rings, using density functional theory (DFT) calculations performed with the Gaussian16
program. To determine the aromaticity of the molecules, the NICS index has been analysed to
identify the presence of diatropic currents, indicative of aromaticity, and paratropic currents,
indicative of antiaromaticity, within the rings of the molecules. Spin density has also been used
to locate unpaired electrons.
The results indicate that molecules with the highest number of Baird rings combined with closedshell Clar π-sextets, with all electrons paired, are particularly stable in the triplet state. However,
steric effects can increase the energy of the molecules, decreasing their aromatic stability in both
electronic states. Additionally, the Radenkovic model used to predict triplet state energies has
been validated, and Leyva-Parra's theory has been applied to analyse how the antiaromatic
character of the central ring in the ground singlet state influences the energy difference between
the singlet (S0) and triplet (T1) states.
In conclusion, this work demonstrates that the combined use of Baird and Clar's rules can help
to better understand the behaviour of compounds containing rings with 4n and 4n+2 π electrons
in their different electronic states, significantly contributing to the theoretical chemistry of
aromatic and antiaromatic compounds
2024-07-01T00:00:00ZAvaluació de la capacitat de tractaments terciaris d’aigües residuals basats en Daphnia magna per filtrar nanopartícules metàl·liques en condicions controlades i en presència de microplàstics : estudis de laboratoriGarcia Metje, Clàudiahttp://hdl.handle.net/10256/262652025-02-03T09:49:39Z2024-07-01T00:00:00ZAvaluació de la capacitat de tractaments terciaris d’aigües residuals basats en Daphnia magna per filtrar nanopartícules metàl·liques en condicions controlades i en presència de microplàstics : estudis de laboratori
Garcia Metje, Clàudia
At present, the increase in the nanotechnology industry has led to a rise in the use of
nanoparticles (NPs). These have very interesting properties that allow for applications in
different sectors, such as medical, technological, and energy. In this case, we will focus
the study on silver nanoparticles (AgNPs), highly used in the medical industry thanks to
their antibacterial properties, and titanium oxide nanoparticles (TiO2NPs), with important
applications in daily consumer products. These nanoparticles, like microplastics,
accumulate excessively in ecosystems, causing a negative effect on the life forms
present in them.
Regarding the 1960s and 1970s, the mass use of plastics experienced significant
expansion due to the increased production of plastic products. As a result, ecosystems
have suffered an uncontrolled rise in waste, leading to the accumulation of MP,
negatively affecting the fauna and flora of the ecosystems.
This study examines the effect of NPs and MPs in the presence of Daphnia magna (D.
magna). D. magna is a small crustacean capable of ingesting or eliminating small
particles that do not precipitate in secondary sedimentation tanks. For this reason,
laboratory studies are conducted to simultaneously assess the toxicity of NPs and the
presence of MP in D. magna, as well as to determine the metal absorption capacity of
these organisms.
AgNPs, TiO2NPs, and polyethylene MP were used in the various experiments. Studies
were conducted on the stability of NPs in different concentrations of humic acids and
surfactants, as well as working with NPs of different sizes and coatings to determine their
behavior and evaluate the effect caused by the presence of D. magna.
First, it was determined that D. magna is capable of surviving for a certain period under
stress conditions and assimilating some of the present metal. It is important that the
presence of MP negatively affects survival. Additionally, glass wool was established as
the most adequate filtration method among those evaluated for nanoparticle
suspensions. Finally, in scanning electron microscope (SEM) studies, the presence of
AgNPs in the solutions was verified after 72 hours under typical laboratory conditions
and in the presence of light, although they appear to be aggregated. As for TiO2NPs, it
was found that after 72 hours, there are no nanoparticles present, corroborating previous
results obtained by ICP-MS, where a similar behavior between ionic titanium and
TiO2NPs was observed
2024-07-01T00:00:00ZAvaluació de l’eficiència de sistemes de tractament terciaris basats en la natura : eliminació de contaminants emergentsSorroche Bonet, Judithhttp://hdl.handle.net/10256/262642025-02-03T09:44:38Z2024-07-01T00:00:00ZAvaluació de l’eficiència de sistemes de tractament terciaris basats en la natura : eliminació de contaminants emergents
Sorroche Bonet, Judith
2024-07-01T00:00:00Z