Presence Of CuCl Research Articles

Radical arylation of thiosemicarbazide and acetone thiosemicarbazone by aryldiazonium borofluorides

1. The homolytic arylation of thiosemicarbazide and acetone thiosemicarbazone with phenyldiazonium borofluoride in the presence of CuCl2·2H2O and with p-nitrophenyldiazonium borofluoride in absence of the copper salt forms S-arylisothiosemicarbazide and its derivatives. 2. The radical mechanism of arylation by p-nitrophenyldiazonium borofluoride was demonstrated by ESR.

Formation of unsaturated bicyclic ?-butyrolactone by oxidative dimerization of 2-methyl-2-ethynylcyclopropanecarboxylic acid

The oxidative dimerization of a mixture of the trans and cis isomers of 2-methyl-2-ethynylcyclopropanecarboxylic acid in the presence of CuCl and NH4Cl gives, along with bis(trans-1-methyl-2-carboxyl-1-cyclopropyl)diacetylene (53% yield), also the corresponding dilactone, and specifically bi(1-methyl-4-oxo-3-oxabicyclo[3.1.0]-2-hexalidene)methyl (14% yield), which is probably formed via the intramolecular cyclization of the intermediately formed bis(cis-1-methyl-2-carboxy-1-cyclopropyl) diacetylene.

Metals in organic syntheses : V. The gattermann-koch synthesis of aromatic aldehydes promoted by CuCl(PPh 3) n ( n = 0, 1 or 3). Is the cuprous complex necessary in the synthesis of tolualdehyde?

The use of CuCl(PPh 3) in place of CuCl in the Gattermann-Koch synthesis slightly improves the yield of benzaldehyde but lowers the yield of tolualdehyde. The poorest yields are obtained in the presence of CuCl(PPh 3) 3. The formation of tolualdehyde from toluence and carbon monoxide in the presence of AlCl 3 and HCl is faster in the presence of CuCl, but higher yields are obtained in its absence and using an excess of hydrocarbon. In competitive experiments carried out using benzene and toluene together in equimolecular amounts, only tolualdehyde was formed, supporting the view that an electrophilic substitution is involved.

Niacinamide requirement for growth of Kluyveromyces lactis in minimal medium

Although Kluyveromyces lactis has been used extensively for investigating a variety of metabolic processes, the minimum nutritional requirements for growth of this yeast have not been described. We have determined these minimal requirements and formulated a simple medium which provided growth, as measured turbidometrically, comparable to that obtained with complex media. The medium consisted of the following ingredients per liter: 20 g glucose; 0.41 g MgCl 2; 2.4 g ammonium sulfate; 6.8 g KH 2PO 4; 12.12 g K 2HPO 4; 1200 μg niacinamide; 60 μg biotin; and 6000 μg pantothenic acid. Of the vitamins included, only niacinamide was strictly required to achieve maximum growth. Addition of biotin and pantothenic acid accelerated growth but did not increase the maximum amount of growth which was obtained in the presence of niacinamide alone. Niacin was substituted for niacinamide with no change in growth characteristics. The addition of MnCl 2, ZnCl 2, CaCl 2, and FeCl 2 had no effect on growth but the presence of CuCl 2 at 0.4 m m caused an almost complete inhibition of growth. Mg 2+ ions were required for growth.

Inactivation of bacteriophage øX174 by mitomycin C in the presence of sodium hydrosulfite and cupric ions

Bacteriophage øX174 was inactivated by mitomycin C reduced with sodium hydrosulfite in the presence of cupric ions (Cu 2+). 99% of the phage particles lost their plaque-forming abilities when incubated with 1.5 · 10 −4 M mitomycin C, 5.7 · 10 −4 M sodium hydrosulfite and 1.0 · 10 −4 M CuCl 2 for 120 min at 37°C in 0.05 M Tris-HCl buffer (pH 8.1). Sodium borohydride and thiol-reducing agents such as L-cysteine, 2-mercaptoethanol or dithiothreitol could not serve as a substitute for sodium hydrosulfite and other transition metal ions such as Fe 2+, Fe 3+, Mn 2+, Co 2+ and Zn 2+ were of no effect. Inactivated phage sedimented at 114S just as intact phage, but phage DNA was degraded. Strand-scission was observed when øX174 single-stranded DNA was directly reacted with mitomycin C reduced with sodium hydrosulfite in the presence of CuCl 2. Phage inactivation was inhibited by catalase, EDTA and several scavengers such as cysteamine, 2-aminoethylisothiuronium bromide HBr (AET), 4,5-dihydroxy-1,3-benzenedisulfonic acid (Tiron) or 1,4-diazabicyclo[2,2,2]octane (DABCO). These results suggest that free oxygen radicals and mitomycin C semiquinone radical generated during autoxidation of reduced mitomycin C in the presence of cupric ions cause the degradation of øX174 DNA.

Vinyl polymerization. CCCLXXVIII. Radical polymerization of methyl methacrylate with starch in aqueous solution of CU(II) ion

AbstractThe polymerization of methyl methacrylate(MMA) initiated with starch dissolved in water was carried out in the presence of Cu(II) ion. It was concluded that the polymerization proceeded in the water phase, particularly in the hydrophobic areas (or micelles) formed by the starch. The initiation mechanism was discussed. The formation of a complex of Cu(II) ion with starch and water was confirmed by the measurements of electric conductance and difference spectrum of the starch solution in the presence of CuCl2.

Vinyl Polymerization. CCCLXXXV. Polymerization of Methyl Methacrylate Initiated with Sodium Poly(L-glutamate) in Aqueous Medium of Cu(II) Ion

The polymerization of methyl methacrylate (MM A) by sodium poly(L-glutamate) (PLG-Na), copper(II) chloride and water was carried out. The effects of the pH of the aqueous solution and the mass of each component on the conversion were studied. The polymerization proceeded in an acidic medium through a radical mechanism. The initiation mechanism was discussed. The formation of the complex of Cu(II) ion with PLG-Na and water was confirmed by measurements of electric conductivity and UV spectrum of the PLG-Na aqueous solution in the presence of CuCl2.

Arylation of diphenyl disulfide using phenyl and p-nitrophenyl radicals

1. Phenyl aryl sulfides were obtained by the arylation of diphenyl disulfide using aryl radicals generated by two methods: 1) by the decomposition of aryldiazonium chlorides in the presence of CuCl2, and 2) by the thermolysis of phenylazotriphenylmethane. 2. The arylation of diphenyl disulfide using aryldiazonium chlorides in the presence of CuCl2 and phenylazotriphenylmethane has a great similarity, which makes it possible to propose that their mechanism is close.

Kinetics of absorption of HCl in terpenes and isoamylene

The kinetics of reaction between HCl gas and terpenes (α-pinene, myrcene, camphene, Δ 3-carene) and isoamylene (2-methyl-2-butene) were studied, The reactions of HCl with α-pinene and Δ 3-carene were found to be zero order with respect to HCl and second order with respect to the olefin. T The reactions between HCl and myrcene (in the presence of CuCl as a catalyst) and camphene were found to be first order with respect to HCl as well as The absorption of HCl in 2-methyl-2-butene was found to be second order with respect to HCl and first order with respect to 2-methyl-2-butene. The valu

ChemInform Abstract: PREPARATION OF 2‐CHLOROETHYL ALKYLSULFONES BY THE ADDITION OF ALKANESULFONYL CHLORIDES TO ETHYLENE

A study was made of the addition of alkanesulfonyl chlorides to ethylene under pressure in the presence of CuCl2, Cu2Cl2, and their mixtures, and it was shown that here the corresponding 2-chloroethyl alkyl sulfones are formed in 90–95% yield when based on reacted alkane-sulfonyl chloride, with a 35–40% conversion of the latter.

Preparation of 2-chloroethyl alkyl sulfones by the addition of alkanesulfonyl chlorides to ethylene

A study was made of the addition of alkanesulfonyl chlorides to ethylene under pressure in the presence of CuCl2, Cu2Cl2, and their mixtures, and it was shown that here the corresponding 2-chloroethyl alkyl sulfones are formed in 90–95% yield when based on reacted alkane-sulfonyl chloride, with a 35–40% conversion of the latter.

Radical arylation of disulfides

1. The radical arylation of the diphenyl and dibenzyl disulfides with aryldiazonium chlorides in the presence of CuCl2 leads to the formation of unsymmetrical diaryl and aryl benzyl sulfides. 2. Using the EPR method and 2-methyl-2-nitrosopropane as the spin trap it was shown that the reaction of phenyl radicals with diphenyl disulfide leads to the formation of phenylthio radicals.

Chemical behavior of optically active poly[thio 1‐(N,N‐disubstituted aminomethyl) ethylenes] in CuCl2‐methanol mixtures: Induced optical activity of bound Cu(II)

Abstract(+)‐Poly[thio 1‐(N‐sec‐butyl‐N‐methylaminomethyl) ethylene] (I) and (‐)‐poly[thio 1‐(N‐methyl‐N‐(1‐phenylethyl)aminomethyl) ethylene] (II) are soluble in methanol or in a 10/90 dioxane‐methanol mixture in the presence of CuCl2. This salting‐in effect results from interactions between macromolecules and this salt. With a large excess of salt (molar ratio > 8) a precipitate is obtained whose composition is close to a CuCl2:monomer unit ratio of unity. Ultraviolet, optical rotatory dispersion (ORD) and circular dichroism (CD) spectra in solution are described. The three extrinsic Cotton effects observed between 300 and 800 nm are assigned to charge transfer and d‐d electronic transitions of Cu(II) complexed with the macromolecules. In the same solvent system, Cu(II) shows similar induced optical activity in the presence of a nonaminated homolog, (+)‐poly(propylene sulfide) taken as a model of the chains of I and II. No extrinsic Cotton effects are observed in the presence of an optically active tertiary amine without the thioether sulfur atom, (+)‐N‐sec‐butyl‐N‐methyl‐N‐(oxirane‐2‐ylmethyl)amine. It is concluded that Cu(II) gives rise to charge‐transfer complexes with sulfur atoms, while tertiary amine groups are probably protonated in this particular medium.

Radical reaction of ethylene sulfide with aryldiazonium chloeides in presence of CuCl2

1. The reaction of ethylene sulfide with the p-anisyl- and p-tolydiazonium chlorides in the presence of CuCl2 leads to the correspondingβ-chloroethyl aryl sulfides and diaryl disulfides. 2. Radicals of type ArSCH2CH2 are formed when aryl radicals act on ethylene sulfide, which are stabilized either by fragmentation (formation of disulfide) or, without fragmentation, by reaction with CuCl2 (formation ofβ-chloroethyl aryl sulfide).

Action des bromures de perfluoroalkylmagnésiums sur les aldéhydes α,βéthyléniques

Perfluoroalkylmagnesium bromide, C n F 2 n+1 MgBr ( n = 2, 6, 8), reacts with α,β-unsaturated aldehydes to give allylic alcohols as the sole products. No attack on the β-carbon atom of the carbonyl was detected, even when the reaction was carried out in the presence of CuCl. Part of the Grignard reagent decomposes to trans-R FCFCFBr and trans-R FCFCFI. Neither a mechanism involving dissociation into R + F MgX - nor the formation of a carbene intermediate is capable of explaining the thermal decomposition of the Grignard reagent.

Arylation of thiourea by aryldiazonium salts

1. In the presence of cupric chloride, aryldiazonium chlorides arylate thiourea to give S-arylisothiuronium compounds. 2. In the absence of CuCl2, the reaction of the p-chlorophenyldiazonium fluoborate and chloride with thiourea gives the p-phenylenediisothiuronium compound, and the p-chlorophenylisothiuronium compound in the presence of CuCl2.

Formation of hexenes from 1-pentanol in the presence of cupric chloride

The dehydration of 1-pentanol in the presence of CuCl2 at 140–200‡ and a pressure of 5–80 atm, in either a CO or a N2 atmosphere, is accompanied by the formation, along with pentenes, of large amounts of hexenes (mainly cis- and trans-2-hexene).

Sur la tension d'electrode du cuivre en presence d'eau de bruxelles: Influence de la lumiere et des conditions de circulation de l'eau

Descaled copper exposed to continuously circulating Brussels mains water shows initially an induction period during which the metal potential is relatively base ~ 30-0 mV/sce; during this period the metal becomes progressively covered with cuprous oxide, light has no sensible influence on the electrode potential, and stoppage of the water flow produces a slight rise of potential. After the induction period, there is a continuous rise of potential, light produces a very rapid potential fall (which can be considerable), and stoppage of water flow no longer produces a potential rise, but a slow fall. The most negative potential produced by stoppage of flow ~ 250 mV/sce—is substantially the same as that produced by this action of light, and the same as that shown by freshly descaled copper exposed to oxygen-free Brussels water: the value corresponds to that for the simultaneous stability of Cu and Cu 2O in that water. Consequently, after the induction period, light and flow stoppage both produce contact between metallic copper and water. Light presumably produces photochemical transformation of cuprous chloride into metallic copper and a cupric salt; this action of light may provide a means for detecting CuCl in the Cu 2O layer formed during the induction period, and hence a means for determining the conditions leading to localized corrosion, which we believe to be linked with this presence of CuCl. The effect of flow stoppage is presumably due to the opening of the entrances to the corrosion pits, previously closed and filled with hydrolysis products of CuCl (Cu 2O and HCl) in presence of which copper is ‘bare’, free from protective oxide; this opening of previously closed pits produces a more or less rapid dilution by water, with the formation of low-potential anodes.