A5031256745- Photochemistry and Electron Transfer Studies
- Bioactive Compounds and Antitumor Agents
- Porphyrin and Phthalocyanine Chemistry
- Synthesis of Organic Compounds
- Luminescence and Fluorescent Materials
- Free Radicals and Antioxidants
- Morinda citrifolia extract uses
- Synthesis and Reactions of Organic Compounds
- Synthesis and properties of polymers
- Nonlinear Optical Materials Research
- Synthesis and Characterization of Heterocyclic Compounds
- Oxidative Organic Chemistry Reactions
- Forensic Fingerprint Detection Methods
- Spectroscopy and Quantum Chemical Studies
- Mesoporous Materials and Catalysis
- Radical Photochemical Reactions
- Photochromic and Fluorescence Chemistry
- Organic Chemistry Cycloaddition Reactions
- Inorganic and Organometallic Chemistry
- Synthesis and Biological Evaluation
- Photopolymerization techniques and applications
- Analytical Chemistry and Sensors
- Fungal Infections and Studies
- Synthesis and biological activity
- Dental materials and restorations
Universidade Federal do Rio Grande do Sul
2010-2021
Materia (United States)
2018
Heidelberg University
2003
Universidade de São Paulo
2003
Instituto de Química Orgánica General
1985-1992
Consejo Superior de Investigaciones Científicas
1989
The antibacterial activity of a series 1,4-naphthoquinones was demonstrated. Disk diffusion tests were carried out against several Gram-positive and Gram-negative bacteria. compound 5-amino-8-hydroxy-1,4-naphthoquinone the most effective, presenting inhibition zones measuring 20 mm staphylococci, streptococci bacilli at 50 microg/ml. Methicillin-resistant Staphylococcus aureus clinical isolates this bacterium also inhibited. Naphthazarin, 5-acetamido-8-hydroxy-1,4-naphthoquinone,...
Five silyl-functionalized benzazole dyes, fluorescent by excited state intramolecular proton transfer (ESIPT) mechanism, were synthesized reaction of amino derivatives with 3-(triethoxysilyl)propyl isocyanate. Fluorescent silica gels prepared and monolithic aerogels (d ≈ 0.18 g cm−3) obtained via supercritical CO2 drying the gel. The photophysical behaviour dyes was investigated UV–vis steady-state fluorescence spectroscopy.
Two Schiff bases were synthesized by reaction of 2-(4'-aminophenyl)benzoxazole derivatives with 4-N,N-diethylaminobenzaldehyde. UV-visible (UV-vis) and steady-state fluorescence in solution applied order to characterize its photophysical behavior. The present absorption the UV region emission blue-green region, a large Stokes' shift. UV-vis data indicates that each dye behaves as two different chromophores ground state. spectra 5a show an intramolecular proton transfer (ESIPT) mechanism...
Diels-Alder reactions of (S)-2-(p-tolylsulfinyl)-1,4-benzoquinone (1a) with cyclic (cyclopentadiene and cyclohexadiene) acyclic dienes (1-[(trimethylsilyl)oxy]-1,3-butadiene trans-piperylene) under different thermal Lewis acid conditions are reported. Chemoselectivity (reactions on C(2)-C(3) versus C(5)-C(6) double bonds) is mainly related to the (on C(5)-C(6)) or C(2)-C(3)) structure diene. The high pi-facial selectivity observed could be controlled by choosing adequate experimental conditions.
The Sonogashira coupling of 2-bromopyridine with 8-quinolinyl-acetylene affords 2-pyridinyl-8-quinolinyl-acetylene (1) in high yields. chloropalladation 1 Li(2)PdCl(4) methanol at room temperature the pincer palladacycle (C(5)H(4)N-2-C=C(Cl)-8-C(9)H(6)kappaN,kappaC,kappaN)PdCl (2) 63% yield. X-ray molecular structure shows that it is totally flat and associated pairs though pi-stacking between alternate pyridine-quinoline moieties (3.448 A). are also connected by an interpair distance 3.452...
New fluorescent succinimidyl benzazole derivatives were synthesised and successfully used to stain Candida albicans ATCC 10231 cells. The dyes characterised by means of infrared, 13C 1H NMR spectroscopies elemental analysis. UV–Vis steady-state fluorescence in solution also applied characterise their photophysical behaviour. novel the yellow–green region a phototautomerism excited state (ESIPT) with large Stokes shift (9065–10962 cm−1). Dual could be observed depending on solvent polarity....
Abstract Six new fluorescent monomers were synthesized by reaction of 2‐(5′‐amino‐2′‐hydroxyphenyl)benzazole derivatives with acryloyl chloride and allyl bromide. UV–vis steady‐state fluorescence in solution used to characterize its photophysical behavior. The are the blue, green, yellow, red region, a large Stokes shift between 92 226 nm. A dual ascribed conformational equilibrium ground state dependent on solvent polarity could be observed emission spectra monomers. radical polymerization...
New silica hybrid materials were obtained by incorporation of two benzimidazole dyes in the network sol–gel technique, using tetraethylorthosilicate (TEOS) as inorganic precursor. Several syntheses performed with catalysts (HF and NaF) producing powders monoliths different characteristics. The dye 2-(2′-hydroxy-5′-aminophenyl)benzimidazole was dispersed physically adsorbed matrix, 2′(5′-N-(3-triethoxysilyl)propylurea-2′-hydroxyphenyl)benzimidazole silylated, becoming chemically bonded to...
For the first time, incorporation of 2,5-bis(benzoxazol-2′-yl)-4-methoxyphenol (BM) in a silica matrix by sol–gel method has been accomplished, producing transparent and translucent monoliths with fluorescence properties. The intensity wavelength range bands F1 (primary structures) F2 (proton-transferred forms) were extremely sensitive to presence solvents dye concentration pores. band was observed when pores contained solvent; however, after solvent evaporation, interactions host hindered...