Search results for "Chloride"
showing 10 items of 1691 documents
Organic chlorine compounds in lake sediments. V. Bottom of Baikal near a pulp mill
1990
Abstract Organically bound chlorine (OCl) together with inorganic chloride (Cl − ) was measured from bottom surface samples of the Lake Baikal near a pulp mill and compared to organic matter contents (OM). Although total contents of OCl, Cl − and OM were much lower than, the ratio of OCl to OM was of the same order of magnitude as in pulp mill recipients of Finland.
An approximate theoretical impedance analysis of the anodic dissolution of nickel across nickel(II) stabilised by means of competitive anions
2007
Abstract A theoretical impedance function for the anodic dissolution of nickel is developed by considering the hypothesis that there are two competitive anions which participate in the stabilization of the electrogenerated Ni(II) species. The experimental effect of chloride ion concentration on nickel electrodissolution process is analyzed by means of a mechanism that considers this competency. It is observed that an increased Cl − concentration causes an increase in Ni(I) surface concentration and a decrease in the kinetic constant rates of the considered mechanism. Moreover, an increased chloride concentration causes a flattening in the low frequencies inductive loop in the Nyquist plot r…
Substituent effect on oxidative cyclization of aldehyde thiosemicarbazones with ferric chloride
1991
The reactivity of aldehyde thiosemicarbazones 1 with ferric chloride solutions was examined. When compounds 1 are not substituted on the N-2 nitrogen atom formation of 1,3,4-thiadiazole 3 heterocyclic ring was observed. In contrast 1,2,4-triazoline 4 and/or 1,3,4-thiadiazoline 5 heterocyclic rings were afforded when N-2 nitrogen atom carried a methyl or a phenyl group. The reaction mechanism is also discussed.
ChemInform Abstract: Substituent Effect on Oxidative Cyclization of Aldehyde Thiosemicarbazones with Ferric Chloride.
2010
The reactivity of aldehyde thiosemicarbazones 1 with ferric chloride solutions was examined. When compounds 1 are not substituted on the N-2 nitrogen atom formation of 1,3,4-thiadiazole 3 heterocyclic ring was observed. In contrast 1,2,4-triazoline 4 and/or 1,3,4-thiadiazoline 5 heterocyclic rings were afforded when N-2 nitrogen atom carried a methyl or a phenyl group. The reaction mechanism is also discussed.
2,5-Dialkoxysubstituierte Oligo- und Poly(1,4-phenylenethenylen)e
1994
2,5-Dialkoxy Substituted Oligo- and Poly(1,4-phenyleneethenylene)s O-Alkylation and regioselective Rieche formylation of 2-methylhydroquinone (1) yields the 2,5-dialkoxy-4-methylbenzaldehydes 4a–j. The corresponding azomethines 5a–j enter in a strongly alkaline medium a selfcondensation reaction leading to the title compounds 6/7a–j. These conjugated oligomers and polymers possess highly regular structures with exclusively (E)-configurated double bonds. GPC, IR, 1H-, 13C-NMR and MS-FD measurements were used for their characterization. Somewhat different results were obtained for the similarly prepared Schiff base 5l which contains chlorine substituents in the side chains. Cleavage of hydrog…
NonclassicalPschorr andSandmeyer Reactions in Pyrazole Series
2005
The diazonium salt derived from 4-amino-N,1,3-trimethyl-N-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-1H-pyrazole-5-carboxamide (14) was reacted with a mixture of CuSO4 and NaCl, with ascorbic acid as an initiator to afford the planar derivative 4,6-dihydro-1,4,6,8-tetramethyl-3-phenyldipyrazolo[3,4-b:4′,3′-d]pyridin-5(3H)-one (16) and its unexpected isomer 4,6-dihydro-3,4,6,8-tetramethyl-1-phenyldipyrazolo[4,3-b:4′,3′-d]pyridin-5(1H)-one (17), as well as the epimers (3S,4S)- (or (3S,4R)-) and (3S,4R)- (or (3S,4S)-) 4-chloro-2,4-dihydro-1′,3′,5,5′-tetramethyl-2-phenylspiro[pyrazole-3,4′(1′H)-pyrrolo[3,4-c]pyrazol]-6′(5′H)-one (18a and b, respectively). Epimers 18a and b were converted under basic c…
The effect of osmo-induced stress on product formation by Zymomonas mobilis on sucrose
2000
The intensification of biosynthesis of fructooligosaccharides in the presence of high salt concentrations was observed during sucrose (10%) fermentation by Zymomonas mobilis 113S. A 0.6 M NaCl concentration led to an increase of oligosaccharide productivity by 3.5-fold. Sorbitol formation was increased in the presence of 0.16 M NaCl and was inhibited at highest salt concentrations. In a medium with high (65%, w/w) sucrose content the salts gave inhibitory effects on fructooligosaccharide production by lyophilised Z. mobilis cells. Influence of salts on gluconic acid and sorbitol formation under these conditions was studied. The ratio of oligosaccharides and gluconic acid productivity (Qolig…
Carbonic anhydrase inhibitors
1999
Reaction of 20 aromatic/heterocyclic sulfonamides containing a free amino, imino, hydrazino or hydroxyl group, with 8-quinoline-sulfonyl chloride afforded a series of water-soluble (as hydrochloride or triflate salts) compounds. The new derivatives were assayed as inhibitors of the zinc enzyme carbonic anhydrase (CA), and more precisely of three of its isozymes, CA I, II (cytosolic forms) and IV (membrane-bound form), involved in important physiological processes. Efficient inhibition was observed against all three isozymes, but especially against CA II (in nanomolar range), which is the isozyme known to play a critical role in aqueous humor secretion within the ciliary processes of the eye…
Stereocontrolled solid-phase synthesis of fluorinated partially-modified retropeptides via tandem aza-Michael/enolate-protonation
2003
N-Acylation of Wang resin-bound l-α-amino acids with 2-trifluoromethyl-propenoyl chloride, followed by asymmetric tandem aza-Michael/enolate-protonation by a series of l-α-amino esters and final release from the resin, afforded a representative library of partially-modified retropeptides incorporating a stereodefined trifluoroalanine surrogate. The stereocontrol can be dramatically improved (up to 15:1) by using apolar solvents like carbon tetrachloride and DABCO as base.
Photocatalytic Selective Oxidation of 4-Methoxybenzyl Alcohol to Aldehyde in Aqueous Suspension of Home-Prepared Titanium Dioxide Catalyst
2007
WOS: 000246040000026