Ionic liquids (ILs) have recently emerged as an extremely promising medium for the extraction of metals from aqueous phases. ILs are salts that liquid at room temperature, and physical chemical properties make them potentially valuable replacements organic molecular solvents. However, same ionic character gives rise to mechanisms no analogue in liquids. While generally exist hydrophobic neutral complexes liquids, charged incorporating ligands may be highly soluble IL Further, permits ion...

We synthesized and analyzed 19 compounds of 3'- (meta-) 4'- (para-) substituted 2-[(R-phenyl)amine]-1,4-naphthalenediones (PANs) R = p-MeO, p-Me, p-Bu, p-Hex, p-Et, m-Me, m-Et, H, p-Cl, p-Br, m-F, m-Cl, p-COCH(3), m-CN, m-NO(2), m-COOH, p-COOH. Despite the fact that nitrogen atom, which binds quinone with meta- para-substituted ring, interferes direct conjugation between both rings, UV-vis spectra these show existence an intramolecular electronic transfer from respective aniline to...

The redox chemistry of different quinones is focused to understand how the reduction products can be stabilized by supramolecular interactions or they react through proton transfer mechanisms. This reactivity depends not only on electronic properties substituents, but also structural effects related formation intra and intermolecular hydrogen bonds. In order explore a wider spectrum for covalent non-covalent interactions, several donors substituted quinone structures have been tested in two...

Optical-coherence tomography (OCT) is a technique that employs light in order to measure the internal structure of semi-transparent, e.g. biological, samples. It based on interference pattern low-coherence light. Quantum-OCT (QOCT), instead, correlation properties entangled photon pairs, for example, generated by process spontaneous parametric downconversion (SPDC). The usual QOCT scheme uses pairs characterised joint-spectral amplitude with strict spectral anti-correlations. has been shown...

Thirteen C6 para-substituted anilinebenzoquinones derived from perezone (PZ) (2-(1,5-dimethyl-4-hexenyl)-3-hydroxy-5-methyl-1,4-benzoquinone) were prepared to analyze the effect of substituents on quinone electronic properties. The a hydrogen bond between α-hydroxy and carbonyl C4−O4 groups was determined in derivatives by substituting electron-donor electron-acceptor such as −OMe, −Me, −Br, −CN comparing −OH (APZs) −OMe (APZms) derivatives. Reduction potentials these compounds measured...

On the basis of voltammetric behaviors obtained for electrochemical reduction a series α-NH-quinones (Q) increasing basicity (5H-benzo[b]carbazole-6,11-dione (BCD), 2-{[4'-(trifluoromethyl)phenyl]amine}-1,4-naphthalenedione 2-(phenylamine)-1,4-naphthalenedione (PAN), 2-[(4'-methoxyphenyl)amine]-1,4-naphthalenedione (p-MeOPAN), and 2,5-di(α-methylbenzylamine)-1,4-benzoquinone (DMeBABQ)), in presence additives with acidity [ethanol (EtOH), phenol(PhOH), benzoic acid (HBz), perchloric it was...

We propose a microfluidic method to measure the refractive index of liquids. This is based on dynamic focusing by capillary when liquids with different indexes are inserted into it. Fabrication such refractometer has been done encapsulating two fibers and capillary. A calibration proposed.

Here we propose optofluidic spherical microlenses that can change their focal distance by varying the refractive index of liquid composes them. These lenses are fabricated in bulk a polymeric mixture. Results characterization study profile lenses, image forming capability, and behavior as function presented. Ionic liquids suggested source useful for fabricating this type lens.

We report the synthesis and voltamperometric reduction of 5H-benzo[b]carbazole-6,11-dione (BCD) its 2-R-substituted derivatives (R = −OMe, −Me, −COMe, −CF3). The electrochemical behavior BCDs was compared to that 2-[(R-phenyl)amine]-1,4-naphthalenediones (PANs) previously studied. Like PANs, exhibit two waves in acetonitrile. first step for represents formation radical anion, half-wave potential (E1/2) values this are less negative than PANs. second wave, corresponding dianion hydroquinone,...

We describe a simple and versatile optical sensing device for measuring refractive index of liquids. The sensor consists sinusoidal relief grating in glass cell. Device calibration is done by pouring the cell different liquids known indices. Each time liquid poured first order intensity measured. fabrication process testing prototype described. An application measurement temperature also presented.

We describe a way of selecting pairs glasses for both thin cemented achromatic doublets and aplanatic with reduced secondary spectrum. By taking one pair at time, we can compute display the spectrum in increasing value. The number solutions based on magnitude alone is huge: 40,804 pairs. Some tests are applied different stages design procedure to reduce acceptable solutions. Aberrations that cannot be corrected, namely, spherochromatism fifth-order spherical aberration, further calculated...

The flux of energy given by the Poynting vector Se and kt-wave normal to geometrical wavefront for extraordinary ray propagating through uniaxial crystals can be evaluated using theory developed Avendaño-Alejo [J. Opt. Soc. Am. A 19, 1668 (2002)] Stavroudis A19, 1674 (2002)]. We give here equations necessary evaluate general dispersion angle Se·kt. Additionally we define two new angles, Se·A kt·A, where is crystal axis vector. With these angles optical path length traversed in a...

We analyze the spatiotemporal intensity of Gaussian temporal envelope pulses with initial durations 200 fs and a carrier wavelength 810 nm at paraxial focal plane an achromatic doublet lens for well-collimated incoming pulse beam by using Seidel aberration theory thin lenses stop lens. effect these aberrations in focusing ultrashort illumination present experimental results focused near-IR doublet.

Six Schiff base copper(II) complexes have been prepared and characterized, elemental analyses, mass, IR electronic spectra, μeff X-ray crystal structures being obtained. The study shows that the geometry around metal atom is square planar for one of only distorted others. Electrochemical studies on complexes, though revealing a dependence Cu(II)/Cu(I) potentials effects, also show these are independent structure observed in solid state. Besides, EPR DMF solution at 193 K suggest different to...

Several studies have described that quinoid rings with electron-rich olefins at remote position experience changes in their redox potential. Since the original description of these changes, different approaches been developed to describe properties binding sites ubiquinones. The origin this phenomenon has attributed lateral chain flexibility and its effect on recognition between proteins substrates associated important biological activity. use electrochemical−electron spin resonance (EC−ESR)...