摘要:

AbstractThe reaction of thionyl chloride with some hydroxymethylanthraquinone derivatives was investigated. The reaction product was found to be dependent on other ring substituents and on the reaction temperature. In the case of amino derivatives and at lower temperatures, chlorosulphinylmethylanthraquinones were obtained; while at higher temperatures, chlorination of the anthraquinone nucleus occurred. Hydroxy derivatives gave only chloromethyl compounds.

ISSN:0375-9210    

DOI:10.1002/jctb.5020250302

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractA rate equation is developed for the liquid phase hydrogenation of aniline over cylindrical catalyst pellets of 30% nickel deposited on clay in a trickle bed reactor. The equation takes into account external and internal diffusional limitations, and describes the experimental data adequately. The hydrogenation reaction is first order with respect to hydrogen and zero order with respect to aniline. Effectiveness factors are in the range 0.003–0.03. Apparent activation energy of the reaction is 12.7 kcal/mol and true activation energy is 39.6 kcal/mo

ISSN:0375-9210    

DOI:10.1002/jctb.5020250303

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractThe catalytic vapour phase isomerisation ofm‐xylene intoo‐ andp‐xylenes was studied in a flow system in the temperature range 460–700 °C, and over a wide range of space velocities on a silica–alumina catalyst. The isomeric distribution of the products, as determined by a combination of spectroscopic and chromatographic methods, was found to be consistent with calculated equilibrium values. Reduced pressures tended to suppress undesirable side reactions such as disproportionation and favoured the isomerisation. First order kinetics appeared to be applicable and the overall activation energy for both isomerisation reactions (i.e. meta‐ to para‐, and meta‐ to ortho‐) was found to be close to 25 kcal/mol, being of the same order of magnitude in both cases. Isomerisation ofo‐,m‐ andp‐xylenes failed to occur even at 600 °C under non‐catalytic thermal treatment, although formation of polynuclear ring systems (“coke”) in small quantities was observed. The results appear to indicate that the mechanism of isomerisation of xylenes over acidic catalysts involves essentially ionic intermediates. Based on the evidence obtained, it is concluded that the vapour phase isomerisation of xylenes apparently proceeds via the formation of a localised π‐complex, leading to a 1,2‐intr

ISSN:0375-9210    

DOI:10.1002/jctb.5020250304

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractThe photochemistry of an anthraquinone‐based disperse dye that gives rise to photocontact dermatitis in workers engaged in its manufacture has been investigated. The main photochemical reaction of the dye is that of efficient production of singlet oxygen which sensitises the oxidation of both tryptophan and lecithin. It is suggested that a similar mechanism is responsible for the photodermatitic activity in human skin and the significance of this mechanism is discussed in relation to lysosome membrane damag

ISSN:0375-9210    

DOI:10.1002/jctb.5020250305

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractThe effect of copper, oxygen and their combined effect on the yields of individual nitroparaffins in the vapour phase nitration of gas propane–butane with nitric acid is studied. It is found that the presence of copper or copper and oxygen in the reactor does not change the total yield of nitrocompounds, while in the presence of oxygen higher yields are obtained. All the additives investigated move the proportion of single nitroparaffins in the product mixture towards higher molecular species, while in the case of nitration without additives this proportion moves in the direction of the nitromethane. With regard to the primary and secondary nitroalkanes, copper does not change their yields, but oxygen increases the yield of secondary one

ISSN:0375-9210    

DOI:10.1002/jctb.5020250306

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractInteractions between dilute aqueous solutions of the triphenylmethane dye Crystal Violet and the disazo dyes Brilliant Orange or Brilliant Yellow at room temperature produce strong metachromic absorptions at 494 nm which are absent from the spectra of either component alone. The addition of acetone, ethanol or methanol to these solutions or raising their temperature reverses the interaction. It is suggested that these observations are consistent with a strong interaction occurring between adjacent molecules of crystal violet which are held together in a specific orientation by interacting with a stereoregular network of disazo dyes held together by hydrogen bonding.

ISSN:0375-9210    

DOI:10.1002/jctb.5020250307

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractA method is described for the estimation of purine and pyrimidine bases on n‐alkane yeasts which employs a simple hydrolysis step with hot 72% perchloric acid followed by separation of the bases by ion‐exchange chromatography. The level of RNA in a sample can be calculated from the amounts of the bases present. The method is believed to be more precise and reliable than other methods employing extraction and u.v. spectrophotometric measureme

ISSN:0375-9210    

DOI:10.1002/jctb.5020250308

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

Abstract1,4‐α‐D‐glucan maltohydrolase (β‐amylase, EC.3.2.1.2.) produced byBacillus polymyxawas isolated and purified. Some of its properties were examined and compared with those of a typical plant β‐amylase. Hydrolysis of periodate oxidised amylose demonstrated an exo mechanism of substrate attack similar to that of sweet potato β‐amylase. The effect of sulphydryl reagents on enzyme activity was similar to that reported for plant β‐amylases. Consistent with the observation that the enzyme has an exo mechanism of action, it also failed to degrade Schardinger cyclodextrins. These latter compounds acted as inhibitors of the enzyme. The optimum temperature for activity was 37 °C. The enzyme was quite stable at temperatures up to and including 37 °C; 90% of the original activity remained after storage at 37 °C for 6 days. However, the stability decreased rapidly when exposed to temperatures above 37 °C; only 20% of the activity remained after 1 h at 45 °C. The hydrolase exhibited a rather sharp optimum at pH 6.8 for stability at 37 °C. However, the enzyme was quite stable in the pH range 6.4–7.2 at 20 °C but it was shown to be less stable in acidic conditions than the

ISSN:0375-9210    

DOI:10.1002/jctb.5020250309

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

ISSN:0375-9210    

DOI:10.1002/jctb.5020250310

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

ISSN:0375-9210    

DOI:10.1002/jctb.5020250301

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY