A5017839433- Photochromic and Fluorescence Chemistry
- Synthesis of Indole Derivatives
- Polydiacetylene-based materials and applications
- Porphyrin and Phthalocyanine Chemistry
- Synthesis of Organic Compounds
- Photopolymerization techniques and applications
- Photoreceptor and optogenetics research
- Oxidative Organic Chemistry Reactions
- Asymmetric Synthesis and Catalysis
- Olfactory and Sensory Function Studies
- Radical Photochemical Reactions
- Advanced Polymer Synthesis and Characterization
- Synthetic Organic Chemistry Methods
- Catalytic Alkyne Reactions
- History and advancements in chemistry
- Electronic and Structural Properties of Oxides
- Fungal Plant Pathogen Control
- Traditional and Medicinal Uses of Annonaceae
- Additive Manufacturing and 3D Printing Technologies
- Electron Spin Resonance Studies
- Neurobiology and Insect Physiology Research
- Plant biochemistry and biosynthesis
- Microwave Dielectric Ceramics Synthesis
- Ferroelectric and Piezoelectric Materials
- Spectroscopy and Quantum Chemical Studies
University of Trás-os-Montes and Alto Douro
2016-2025
Association for the Development of Douro Viticulture
2017
Rede de Química e Tecnologia
2011-2016
Universidade Federal de São Carlos
1995
Photochromic silica nanoparticles (SiO2@NPT), fabricated through the covalent immobilization of silylated naphthopyrans (NPTs) based on 2H-naphtho[1,2-b]pyran (S1, S2) and 3H-naphtho[2,1-b]pyran (S3, S4) or direct adsorption parent (1, 3) onto (SiO2 NPs), were successfully incorporated cotton fabrics by a screen-printing process. Two aqueous acrylic- (AC-) polyurethane- (PU-) inks used as dispersing media. All textiles exhibited reversible photochromism under UV solar irradiation, developing...
Photochromic molecules can reversibly develop color upon irradiation with UV light. These smart molecules, mainly in the naphthopyran family, have been applied success to ophthalmic lenses that darken quickly under sunlight and revert uncolored state after several minutes dark. This slow adaptation absence of light is one limitations due formation an unwanted photoisomer. We designed a new bridged structure which prohibits undesirable, persistent photoisomer thus shows very fast switching...
A series of new photochromic fused-naphthopyrans with an alkyl bridge between the pyran ring and naphthalenic core was synthesized in several steps from 4-(bromomethyl)benzocoumarin. The presence these prevents formation one long-lived photoisomer therefore has a dramatic effect on their properties: UV irradiation common naphthopyrans gives rise to two isomeric colored photoisomers, which fades very slowly is responsible for persistent residual color. excitation uncolored leads only that...
A new type of photochromic naphthopyran with a fused structure was embedded in an organic–inorganic amine–alcohol–silicate hybrid gel producing colourless, transparent and flexible films. Under UV-vis light these materials developed, less than 30 s, intense yellow-orange colours that faded completely the dark 3 min. This behaviour contrasts usual performance common naphthopyrans always generate two coloured species which fade different kinetics, leading to formation residual colour persists...
Hybrid nanomaterials based on the covalent grafting of silylated naphthopyrans (NPTs) onto silica nanoparticles (SiO2 NPs) were successfully prepared and studied as new photochromic materials. They by a two-step protocol consisting (i) NPTs (derivatives from 2H-naphtho[1,2-b]pyran (2H-NPT) 3H-naphtho[2,1-b]pyran (3H-NPT)) silylation microwave-assisted reaction between hydroxyl-substituted 3-(triethoxysilyl)propyl isocyanate, followed (ii) post-grafting SiO2 NPs. In order to study role step,...
The development of photoresponsive textiles with high color contrast, sunlight response, fast coloration/bleaching, and reversible properties has been a major quest for anticounterfeiting, camouflage, UV protection, fashion. WO3 materials are promising building blocks textile applications, but their application limited by slow bleaching under ambient conditions response. Herein, innovative tungsten oxide-based tunable photochromism were produced low-cost, single-step, scalable solvothermal...
A new photochromic fused benzopyran presenting a bridge between the pyran double bond and benzenic ring was prepared. While UV irradiation of usual benzopyrans leads to formation two colored photoisomers with very different thermal stabilities, studies by laser flash photolysis showed that presence this particular prevents undesirable long-lived TT isomer therefore after solution fades following fast monoexponential decay.
An easy synthesis of photochromic naphthopyrans with a lactone ring linking the naphthalene core to pyran double bond is described. UV irradiation (or exposure sunlight) these uncolored compounds provide single photoisomer an intense orange coloration that returns completely initial state much faster than common used in commercial ophthalmic lenses. A polymeric material doped one lactone‐fused develops (ΔAbs = 0.73) when exposed light for 30 s, at room temperature, and just 1 min. The use...
By combining photochromic naphthopyran with a Norrish-type II benzophenone photoinitiator, new photoswitchable photoinitiator was created that is activated by the successive absorption of two different wavelengths. This dual-colour used to prepare various thin solid polymeric materials using UV and visible light LED promote formation radicals initiate polymerization an acrylate monomer. The use this system ensures only areas receive double irradiation polymerize, providing simple way control light.
A new indeno‐fused naphthopyran linked to a benzophenone nucleus was synthesized. This photochromic molecule functions as an efficient photoinitiator of radical polymerization under visible light (405 nm), enabling the straightforward manufacture various detailed, soft and thin solid objects directly from colorless liquid polyacrylate resin.
An efficient synthesis of photochromic fused-naphthopyrans was developed. UV-vis or sunlight irradiation these uncolored compounds in solution led to the formation a single colored photoisomer along with an unusual and bicyclic compound formed through intramolecular photochemical Diels-Alder reaction. Both species faded thermally dark initial form. A mechanism for this transformation is proposed based on NMR studies irradiated solutions. The new have been incorporated into hybrid...
Abstract A new photochromic fused 2 H ‐chromene that has a dehydropyran bridge between the pyran double bond and benzene ring was prepared. Unlike standard ‐chromenes give rise to two coloured species (one short‐ one long‐lived) under UV irradiation, flash photolysis studies on this particular show opening of led formation single, coloured, open bleaches uncoloured initial form in <1 ms. The design avoids undesirable long‐lived, transoid–trans , form; therefore, colour fades very quickly,...
A set of new 1-vinylidene-1,2-dihydro-naphtho[2,1-b]furans were unexpectedly obtained in the reaction 2-naphthol with readily available 1,1,4,4-tetraarylbut-2-yne-1,4-diols. Surprisingly, when adsorbed silica gel, these compounds exhibit photochromism at room temperature, whereas not solution and solid state. UV or sunlight irradiation leads, a few seconds, to formation intense pink/violet green colors that bleach completely minutes dark. These also reversible acidochromic properties...
The reaction of tetraarylbut-2-yne-1,4-diols with electron-rich aromatic compounds at room temperature, under p-TsOH catalysis, affords substituted polycyclic indene derivatives through a domino involving the formation cationic allenylium intermediate. This species can undergo series competitive intramolecular cascade reactions, leading to conjugated inden-2-one. simple method allows efficient synthesis indenes and inden-2-ones, in two steps, from ketones.