摘要:

AbstractThe vapour phase oxidation of ethylene glycol to glyoxal by air was studied in a stainless steel tube reactor using cupric oxide as a catalyst on carriers such as active alumina, pumice stone, silicon carbide, ceramics and fused alumina. A catalyst containing 3 to 5% cupric oxide on pumice stone was found to be satisfactory for the process. The effects of temperature, period of reaction and concentration of ethylene glycol and oxygen on the yield and conversion to glyoxal were studied, and the most suitable conditions were determined for the process. Carbon dioxide and formaldehyde were the major by‐products in the reaction. Formaldehyde was formed mainly due to the homogeneous reactions of ethylene glycol with oxygen in the void space of the reactor. The formation of glyoxal and carbon dioxide were correlated by suitable empirical rate expression

ISSN:0375-9210    

DOI:10.1002/jctb.2720240602

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe introduction of the benzyl group into the aromatic nucleus is brought about by heating benzyl‐α‐ and β‐naphthyl ethers with the aromatic compounds, such as, naphthalene, 2‐methylnaphthalene and isoquinoline. It has been concluded that the reaction depends initially on homolytic fission of the alkyl aryl ether into aryloxy and alkyl free radicals which are able to react with the aromatic nucleus. The homolytic mechanism of the alkylation studied and the isomer distribution in the alkylation products separated are discussed on bases of theories of free valency and atom localisation energy of aromatic

ISSN:0375-9210    

DOI:10.1002/jctb.2720240603

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe u.v. absorption spectra of forty‐one substituted coumarins have been studied in methanol and aqueous methanol over a pH range. The effect of the nature and position of the substituent in the coumarin nucleus is discusse

ISSN:0375-9210    

DOI:10.1002/jctb.2720240604

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractSchmidt discovered in 1925 that an unusual arylation occurred when 1,5‐diamino‐4,8‐dihydroxyanthraquinone‐3,7‐disulphonic acid dissolved in conc, sulphuric acid containing boric acid was treated with phenols or anisole. Schmidt incorrectly assumed that thep‐hydroxyphenyl or anisyl group replaced a sulphonic acid group. It has now been shown that this reaction is a stereospecific Friedel‐Crafts type arylation, the aryl moiety entering ortho to the amino group and trans to the sulphonic acid group. The corresponding 3‐monosulphonic acid undergoes th

ISSN:0375-9210    

DOI:10.1002/jctb.2720240605

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractSilica gel prepared under varying conditions indicated that, in addition to the pH and kind of acid, the mode of adding the solutions govern the evolution of surface area of the produced xerogel. Co‐precipitation with the oxides of iron, copper, or nickel showed a marked effect in decreasing the surface area of the dry gel. Xerogels incorporated with iron oxide suffered from a sharp sintering that appeared upon heating to 900 °C. Copper oxide‐incorporated silicas showed a small decrease in surface area at the same temperature. However, silica incorporated with nickel oxide seems to be resistant to heat treatment at 900 °C, and exhibits only a small change in surface area. Acid treatment of the incorporated silicas resulted in negligible variations in surface area, probably due to the low content of o

ISSN:0375-9210    

DOI:10.1002/jctb.2720240606

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractCritical temperatures and pressures of some organic compounds were measured. There is good agreement between the observed critical pressures and values obtained by extrapolation of equations representing the variation of vapour pressure with temperature in the region of the normal boiling point. An incremental scheme relating critical temperatures to normal boiling points is described and is used for the correlation of the critical temperatures, obtained in this and other investigations, of more than 150 compounds.

ISSN:0375-9210    

DOI:10.1002/jctb.2720240607

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

ISSN:0375-9210    

DOI:10.1002/jctb.2720240608

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

ISSN:0375-9210    

DOI:10.1002/jctb.2720240601

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY