摘要:

AbstractThe isotherms for preferential adsorption from a binary liquid mixture may be of so‐called “U” or “S” shape. Those of “U” shape are in certain cases describable by Langmuir‐type equations in terms of two parameters. These are the relative adsorbability of the two components and the volume of the adsorbed layer, the latter being considerably smaller than the volume of the pores within the particles of the adsorbent. It is shown, how these parameters may be derived from ex

ISSN:0165-0513    

DOI:10.1002/recl.19590780202

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractHydrogenation of 2,6‐dimethyl‐4‐pyrone affords pure 2,6‐dimethyltetrahydropyran‐4‐ol with a modified Raney‐nickel catalyst whereas with a palladium catalyst 2,6‐dimethyltetrahydro‐4‐pyrone is eventually obtained. Partial hydrogenation with a palladium catalyst affords a mixture of 2,6‐dimethyldihydro‐4‐pyrone and 2,6‐dimethyltetrahydro‐4‐pyrone. The latter is hydrogenated to 2,6‐dimethyltetrahydrop

ISSN:0165-0513    

DOI:10.1002/recl.19590780203

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19590780204

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractA completely anhydrous sample of cupric tetramminesulphate has been prepared. The product previously reported to be anhydrous was found to contain up to 4% of moisture on keeping over calcium chloride. Thermal decomposition of the slightly hydrated, as well as the completely anhydrous compounds, was followed in a closed apparatus at atmospheric pressure and/or in a vacuum. Two molecules of ammonia were reversibly liberated on two successive steps. In a vacuum, the completely anhydrous, deep violetblue Cu(NH3)4SO4lost one ammonia molecule at 30° and a second molecule at 55°, giving the pale blue Cu(NH3)2SO4. At temperatures above ∼90°, irreversible decomposition of the diammine occurs with the gradual formation of a dark‐grey to brown product, accompanied by sublimation of ammonium su

ISSN:0165-0513    

DOI:10.1002/recl.19590780205

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe dissociation pressure of cupric tetramminosulphate was measured at different temperatures. Log10P is plotted against 1/T, gave a curve which could be divided into two intersecting lines of different slopes, indicating that the two molecules of ammonia liberated in the decomposition of the tetrammine to give the diammine are set free in two stages; at temperatures lower than 50° the tetrammine decomposes giving the triammine; at higher temperatures, it gives the diammine directly. The heat content change of the system “Δ H” was calculated for each step and found to be 6.1 and 25.5 kcals per molecule for the liberation of the first and second molecules ammonia respectively at low temperatures.The heat of formation of CuSO4.3NH3was calculated as 285.3 kcals per mol

ISSN:0165-0513    

DOI:10.1002/recl.19590780206

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractIn the first publication in this series it was shown that only partial reduction of the pyrazine ring occurs in the catalytic hydrogenation of tetra‐carbethoxypyrazine. The remaining double bonds in the resultant reaction product are apparently stabilised. In agreement with the hypotheses put forward to explain this result, esters of other pyrazine carboxylic acids also are only partially reducible with palladium on carbon at room temperatures. The conclusion must be drawn that a carbalkoxy group attached to a pyrazine ring protects an adjacent double bond in the ring against catalytic hydrogenation.The partially hydrogenated products from the esters of some pyrazine carboxylic acids are extraordinarily labile. Dehydrogenation by dismutation or reoxidation, which occurs to some extent, can be followed from the spectra.Similar phenomena have been encountered in the pyridine series, which may be put forward as supporting the conclusions reache

ISSN:0165-0513    

DOI:10.1002/recl.19590780207

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe system H2S‐C3H8‐H2O was investigated at −3°C. It was found that the H2S/C3H8ratio in the hydrate phase depends on the composition of the coexisting gas phase. In this respect it is similar to the system CH4‐C3H8‐H2O studied previously. Unlike the latter, the present system exhibits a minimum pressure (“azeotrope”). It is shown that the solution theory of clathrates can account for this phenomenon.Our investigation of hydrates in ternary systems leads us to the conclusion that von Stackelberg's distinction between double hydrates and mixed hydrates is not an essential one: both types of hydrates are solid solutions of two volatile solutes in a h

ISSN:0165-0513    

DOI:10.1002/recl.19590780208

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractRecentlyWiehlerandMarionisolated from the seeds of alfalfa(Medicago sativa)thelaevo‐rotatory methyl betaine of hexahydropyridine‐2‐carboxylic acid, for which they suggested the name of (‐)‐homostachydrine.This compound has now been prepared fromL‐(‐)‐hexahydropyridine‐2‐carboxylic acid (L‐(‐)‐pipecolic acid). (‐)‐Homostachydrine therefore

ISSN:0165-0513    

DOI:10.1002/recl.19590780209

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe reaction between epichlorohydrin and ethylthioethynyl‐lithium affords the enynol V and furfuryl ethyl sulphide VI. The same reaction with ethoxyethynyl‐lithium, however, produces the epoxy compound

ISSN:0165-0513    

DOI:10.1002/recl.19590780210

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe lower homologues in the series of the alkylp‐nitrophenyl methyl‐phosphonates have been prepared by reaction betweenp‐nitrophenyl methylphosphonochloridate and an alcohol. Some alkyl methylphosphonochloridates have also been synthesized, starting from methylphosphonic dichloride. Boiling points and refractive indices of the yellowp‐nitrophenyl compounds and of the colourless chloridates have been recorded, as well as the infrared spectrum ofiso‐butylp‐nitrophenyl methyl

ISSN:0165-0513    

DOI:10.1002/recl.19590780211

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY