A5057114335- Photochromic and Fluorescence Chemistry
- Radical Photochemical Reactions
- Luminescence and Fluorescent Materials
- Porphyrin and Phthalocyanine Chemistry
- Synthesis of Organic Compounds
- X-ray Diffraction in Crystallography
- Organic Light-Emitting Diodes Research
- Supramolecular Chemistry and Complexes
- Photochemistry and Electron Transfer Studies
- Phytochemicals and Antioxidant Activities
- Biochemical Analysis and Sensing Techniques
- Advanced Photocatalysis Techniques
- Crystallization and Solubility Studies
- Molecular Sensors and Ion Detection
- TiO2 Photocatalysis and Solar Cells
- Synthesis of Indole Derivatives
- Fermentation and Sensory Analysis
- Multicomponent Synthesis of Heterocycles
- Quantum Dots Synthesis And Properties
- Experimental Learning in Engineering
- Various Chemistry Research Topics
- Crystallography and molecular interactions
- Innovative Teaching Methods
- Plant Gene Expression Analysis
- Inorganic and Organometallic Chemistry
Institute for Biotechnology and Bioengineering
2020-2024
University of Lisbon
2020-2024
Instituto Politécnico de Lisboa
2019-2020
Faculdade de Tecnologia e Ciências
2015
Universidade Nova de Lisboa
2008-2015
Rede de Química e Tecnologia
2008-2015
Laboratório Associado para a Química Verde
2015
Seven flavylium salt dyes were employed for the first time as sensitizers dye-sensitized solar cells (DSSCs). The theoretical and experimental wavelengths of maximum absorbances, HOMO LUMO energy levels, coefficients, oscillator strengths dipole moments are calculated these synthetic dyes. introduction a donor group in molecular structure was investigated. Photophysical photoelectrochemical measurements showed that some analogues anthocyanins very promising DSSC applications. best...
The coronavirus disease (COVID-19) pandemic has changed not only people's daily lives but also the education system. rise of e-learning all across world challenged both students and teachers to adapt digital technologies a novel learning experience on sides. As if COVID-19 was enough, many were facing alien territory organic chemistry for first time. There is no denying that tough subject, several may have preconceived misconceptions. In addition, can be challenging teach remotely. It very...
Thermally activated delayed fluorescence (TADF) molecules offer nowadays a powerful tool in the development of novel organic light emitting diodes due to their capability harvesting energy from non-emissive triplet states without using heavy-metal complexes. TADF emitters have very small difference between singlet and excited states, which makes thermally reverse intersystem crossing back manifold viable. This mechanism generates long-lived component can be explored sensing oxygen...
2-Styryl-1-benzopyrylium derivatives exhibit deeper hues and absorption spectra that are substantially red-shifted when compared with their 2-phenyl-1-benzopyrylium analogues. They follow the same pH light-dependent network of chemical reactions previously described for compounds. In this work, photochromic properties 7-hydroxy-2-(4-hydroxystyryl)-1-benzopyrylium chloride reported. This compound was fully characterized by UV-vis absorption, fluorescence emission, jumps, flash photolysis, its...
2′-Hydroxyflavylium and 2′-hydroxyflavanone derivatives can be interconverted by a precise sequence of pH jumps, through the respective intermediate (mono) ionized trans-chalcones. In acidic neutral media, well known network chemical reactions involving flavylium cation, quinoidal base, hemiketal, cis trans chalcones is established. range 8 < 10, chalcone (Ct) deprotonates evolves to formation flavanone (F). At higher values, di-ionized trans-chalcone stable species, formed from cation....
A multistate molecular dyad containing flavylium and viologen units was synthesized the pH dependent thermodynamics of network completely characterized by a variety spectroscopic techniques such as NMR, UV-vis stopped-flow. The cation is only stable at acidic values. Above ≈ 5 hydration leads to formation hemiketal followed ring-opening tautomerization give cis-chalcone. Finally, this last species isomerizes trans-chalcone. For present system trans-chalcone could be detected being...
Abstract A pH-, light- and redox-responsive flavylium-bipyridinium molecular dyad (bioinspired in natural anthocyanins) was synthesized employed to devise a pseudorotaxane with the macrocycle cucurbit[7]uril (CB7) aqueous solution. The inclusion complex characterized by UV-Vis absorption, fluorescence emission, NMR electrochemical techniques which demonstrate formation of stable binary between CB7 both under acidic neutral conditions. It is noteworthy that tricationic only highly media,...
Abstract Organic Thermally Activated Delayed Fluorescence (TADF) molecules are luminescent compounds capable of harvesting energy from triplet states without using heavy metals. This process results in oxygen‐sensitive, long‐lived delayed emission, suitable for developing optical probes time‐gated cell imaging, oxygen sensors, and singlet photosensitizers. Despite their potential, the use TADF emitters these applications is hindered by poor performance polar media challenge balancing high...
Abstract A symmetric bis(flavylium) constituted by two 7‐hydroxyflavylium moieties linked a methylviologen bridge was synthesized. The thermodynamic and kinetics of the network chemical reactions involving model compound 7‐hydroxy‐4′‐methylflavylium completely characterized means direct reverse pH jumps (stopped flow) flash photolysis. Both compounds follow usual pH‐dependent flavylium derivatives. equilibrium species are cation (acidic species) trans ‐chalcone (basic with an apparent p K ′...
In the present work, five 2-styryl-1-benzopyrylium salts and their relative self-assembly processes towards TiO2 nanocrystalline layers were evaluated as photosensitizers in dye-sensitized solar cells (DSSCs). Integration of these with semiconductor allow for performance highly specific functions suitable smart applications material science. Spectroscopic photoelectrochemical measurements conducted on bio-inspired dyes, solution upon adsorption onto titanium dioxide films, allowed detailed...
The introduction of an ester group in the flavylium core allowed reversible conversion between two different compounds each one exhibiting its own reaction network. An unidirectional switching cycle 7-diethylamino-2-(4-(methoxycarbonyl)phenyl)-1-benzopyrylium and 2-(4-carboxyphenyl)-7-diethylamino-1-benzopyrylium was achieved by means alternate acid base stimuli. Addition to a methanolic solution derivative gives rise trans-chalcone parent carboxylic acid, which upon acidification forms...
The study of local polarity at the nanoscale is crucial importance for development smart drug delivery systems and photonic materials frequently accomplished with use luminescent tracer dyes. Nile Red often used this purpose, owing to its polarity-sensitive internal charge transfer transition, but performance affected by specific solute-solvent interactions that prevent widespread applicability. Herein, we develop a new 1,8-naphthalimide dye strong charge-transfer transition results in large...