With 8-hydroxy quinoline

Rhenium can be analyzed by various instrumental techniques that include flame-AA, ICP-AES, ICP-MS, as well as x-ray and neutron activation methods. For flame-AA analysis the metal, its oxide, or other insoluble salts are dissolved in nitric acid or nitric-sulfuric acids, diluted, and aspirated directly into nitrous oxide-acetylene flame. Alternatively, rhenium is chelated with 8-hydroxy quinoline, extracted with methylisobutyl ketone and measured by flame-AA using nitrous oxide-acetylene flame. 

An interesting property of resins impregnated with oximes or oxines is that the selectivity of, for example, copper over iron(III), approaches that of a pure solvent-extraction process only when an inert solvent is present in the pores of the resin.396 Thus, in a /S-hydroxyoxime SIR, the selectivity for copper over iron(III) improved by a factor of 20 when the solvent perchloroethylene was introduced into the SIR, and by a factor of 700 in a similar resin impregnated with 8-hydroxy-quinoline.396 This is believed to be due to kinetic and thermodynamic restrictions in the extraction of iron(III), but not of copper, at an aqueous—organic boundary.396 397... 

Approximately two dozen cations form sparingly soluble chelates with 8-hydroxy-quinoline. The structure of magnesium 8-hydroxyquinolate is typical of these chelates. 

Antico E., Masana A., Salvado V., Hidalgo M., Valiente M. Separation of Pd(II) and Cu(II) in chloride solutions on a glycol methacrylate gel derivatized with 8-hydroxy-quinoline. Journal of Chromatography A 1995 706 159-166. 

K.J., and Bush, A.L (2008) Rapid restoration of cognition in Alzheimer s transgenic mice with 8-hydroxy quinoline analogs is associated with decreased interstitial Abeta. Neuron, 59,43-55. 

Salts of some of the rare earths form fluorescent complexes with 8-hydroxy-quinoline. Yttrium and lutetium show a yellow-green fluorescence and lanthanum a green fluorescence. With oxine, gadolinium gives a deep brown fluorescent complex. Cerium, praseodymium, neodymium, samarium, terbium, dysprosium, erbium, thulium, and ytterbium do not form fluorescent oxinates. 

Another method for the determination of manganese is by precipitation with 8-hydroxy quinoline at pH 6 to 10. 

Little is known quantitatively about substituent effects in the nitration of derivatives of azanaphthalenes. In preparative experiments 4-hydroxy-quinoline, -cinnoline, and -quinazoline give the 6- and 8-nitro compounds, but with nitric acid alone 4-hydroxyquinoline and 2,4-di-hydroxyquinoline react at With nitric acid, 4-hydroxycinnoline... 

Hydroxyquinoline forms the complex with Cu(II) in ratio 1 1 at pH 5-7. The composition of the complex is changed on 1 2 at pH>7. 8-Hydroxy-quinoline accepts bromine therefore its excess has been removed with NaOH solution. The complex was extracted with chloroform. It was shown that double extraction was enough to extract the complex. The detection limit is 5x10 M during 10c and at current generation IxlO A. 

The Conrad-Limpach reaction is a sequence of the following reactions (a) condensation of an arylamine 1 with the ketone or aldehyde of a 3-ketoester or a-formylester 2 providing enamine 3, and (b) cyclization with loss of alcohol to yield 4-hydroxy-quinoline 4. 

Ultraviolet spectra have long been used to study systems of this type. In 1889, comparison of the ultraviolet spectrum of 2-hydroxy-quinoline with those of its O- and A -methylated derivatives led... 

It has been found that epinephrine solutions having a physiological pH and which are stable for months in storage can be prepared by combining with the epinephrine a small amount of sodium bisulfite, boric acid, and oxine (8-hydroxy-quinoline) hereinafter called 8-quinoli-nol and adjusting the pH with an alkali, such as sodium hydroxide, to the desired pH. 

A mixture of 48 parts by weight of diethyl[(3,4-methylenedioxyanilino)methylene] malonate and 500 parts by weight of diphenyl ether is refluxed for 1 hour. The mixture is allowed to cool to about 25°C with stirring and 500 parts by weight of petroleum ether are added. Filtration gives 3-carbethoxy-6,7-methylenedioxy-4-hydroxy-quinoline as a brown solid, MP 276° to 281°C. Several recrystallizations from dimethylformamide gives almost colorless analytical material, MP 285° to 286°C, (decomposes). 

A mixture of 26 parts of 3-carbethoxy-6,7-methylenedioxy-4-hydroxy-quinoline, 16 parts of sodium hydroxide and 50 parts of dimethylformamide is heated at 70° to 75°C for 2 hours, then 31 parts of ethyl iodide is added over 1 hour with continued heating and stirring. After an additional 3 to 4 hours of heating (at 70° to 75°C) and stirring, the mixture is diluted with 500 parts of water, refluxed for 3 to 4 hours, acidified with concentrated hydrochloric acid and filtered to yield 18 to 22 parts of 1-ethyl-1,4-dihydro-6,7-methylene-dioxy-4-oxo-3-quinoline-carboxylic acid, MP 309° to 314°C (decomposes). The analytical sample from dimethylformamide melts at 314° to 316°C (decomposes). 

Hydroxy-containing polymers such as poly(methyl-methacrylate-co-hydroxyethyl methacrylate) [65,66] or secondary cellulose acetate [67,68] were used for this purpose. Vanadium (V) 8-hydroxy quinoline-hydroxy-ethyl methacrylate adduct, prepared by condensation of the latter with a VOQ2OH complex, is polymerized to... 

Heteroatom rings, such as that found in quinoline derivatives, can be generated from amino-ketones with [hydroxy(tosyloxy)iodo]benzene and perchloric acid. Cyclic imines are converted to pyridine derivatives with NCS and then excess sodium methoxide. ... 

Procedures using chelation followed by extraction have been described for manganese using the 8-hydroxy-quinoline-chloroform system [432,444], Dithiocarbamate systems can simultaneously extract manganese, along with other trace metals under suitable conditions [445-447]. 

Resins can also be prepared with chelating functional groups which show selective affinities for certain metals. Iminodiacetic acid, vinylacetylacetone, glyoxal-thiophenol and 8-hydroxy quinoline have all been used to produce these so-called chelating resins. Their selectivities are similar to those of the free reagent. 

Yu et al. synthesized two methyl-substituted Alq3, named tris(2,3-dimethyl-8-hydroxy-quinoline) aluminum complex (Alm23q3, 237) (Scheme 3.72) [264]. This compound emits blue color with an emission peak centered at 470 nm and FWHM of 90 nm. OLEDs with a structure of ITO/TPD/Alm23q3/Mg Ag emit blue light and the luminous efficiency is 0.62 lm/W with a maximum luminance of 5400 cd/m2 at 19 V. 

Replacing the metal Al by a boron atom as the metal chelate center, Tao et al. reported lithium tetra-(2-methyl-8-hydroxy-quinolinato) boron (LiB(qm)4, 240) (Scheme 3.73) quantitatively prepared by reaction of lithium borohydride (LiBH4) with four equivalents of 2-methyl-8-hydroxy-quinoline in ethanol at room temperature [266]. LiB(qm)4 is a pure blue emitter with a maximum peak emission at 470 nm with FWHM of 75 nm. Devices of... 

The utility of [TcOCU] in Tc chemistry is demonstrated by the first synthesis of 8-hydroxy-quinoline (8-Hox, (126)) complexes of technetium in 1984. Ligand (126) is usually one of the first choices to explore the coordination chemistry of an element, but it was as late as 1984 when the first complex with Tc was prepared. It was known that the reaction of [ Tc04] with 8-Hox leads to complexes with high brain uptake, and it was therefore important to define the structure of the active species. This sequence of events is very typical for technetium chemistry. Nuclear medicinal experiments indentify a Tc species with useful biological behavior, which prompts investigations into the basic coordination chemistry to identify the structure of the Tc... 

As a rule, these compounds were obtained using phenols, hydroxy-quinolines, and other hydroxy-substituted heterocycles with UNs. In some cases aminochromenes were subjected to postsynthetic modifications (05BML4745, 07JME417) (Scheme 56). 

Iodoquinol (diiodohydroxyquin) is a halogenated hydroxy-quinoline. It is an effective luminal amebicide that is commonly used with metronidazole to treat amebic infections. Its pharmacokinetic properties are poorly understood. Ninety percent of the drug is retained in the intestine and excreted in the feces. The remainder enters the circulation, has a half-life of 11-14 hours, and is excreted in the urine as glucuronides. 

Solvent extraction offers unique advantages among separation techniques. A system based on extraction into a polymer [poly(vinyl chloride)] as solvent was examined here because of possible advantages in speedy simplicity, sample size, solvent handlingy etc.f especially when coupled with flow injection and an amperometric detector. Solutes examined included salicylic acid and 8-hydroxy quinoline. The apparatus typically consisted of 0.8-mm i.d. X 170-cm coiled tubing that could be connected directly to the injection loop of a flow-injection amperometric detector system containing a nickel oxide electrode. 

A similar pattern of reactivity is observed in quinoline complexes and very detailed studies have confirmed that 8-hydroxyquinolinesulphonic acid undergoes extremely rapid halogenation at the 7-position in the presence of metal ions (Fig. 8-39). Once again, the site of attack is the same as in the free ligand. Similar reactions of 8-hydroxy quinoline complexes occur with a variety of electrophiles. 

Baughman (1992) measured the disappearance rate constants for a number of solvent and disperse azo, anthraquinone, and quinoline dyes in anaerobic sediments. The half-lives ranged from 0.1 to 140 days. Product studies of the azo dyes showed that reduction of the azo linkages and nitro groups resulted in the formation of substituted anilines. The 1,4-diaminoanthraquinone dyes underwent complex reactions thought to involve reduction and replacement of amino with hydroxy groups. Demethylation of methoxyanthraquinone dyes and reduction of anthraquinone dyes to anthrones also was observed. 

Little is known quantitatively about substituent effects in the nitration of derivatives of azanaphthalenes. In preparative experiments 4-hydroxy-quinoline, -cinnoline, and -quinazoline give the 6- and 8-nitro compounds, but with nitric acid alone 4-hydroxyquinoline and 2,4-di-hydroxyquinoline react at C(3).31 With nitric acid, 4-hydroxycinnoline still gives mainly 4-hydroxy-6-nitrocinnoline, but some of the 3-nitro compound can also be isolated.81 51 The change of orientation with reagent could be due to a change to free-base nitration in the more weakly acidic medium, or to the occurrence in nitric acid of nitration via nitrosation.31... 

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