摘要:

AbstractIt is to be expected that for the higher members of a homologous series the heat of formation at a given temperature and state of aggregation is a linear function of the number of C atoms in the normal alkyl group; the increment of the heat of formation per C atom is independent of the nature of the series.Assuming that this law remains true for infinitely diluted solutions, corollaries are derived for various thermodynamic equilibria in which a member of a homologous series occurs.It is found that the relations derived for the distribution equilibrium for two liquid phases at infinite dilution, the equilibrium constant for chemical reactions at infinite dilution, the vapour pressure of a homologous series at a given temperature, etc. contain eitherquantities independent of n (i.e. the number of C atoms in the normal alkyl group)quantities linearly related to n, orquantities whose logarithms are linearly related to n.

ISSN:0165-0513    

DOI:10.1002/recl.19530720102

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

AbstractThe Raman frequency shifts and the depolarization ratio of the Raman lines have been determined for the compounds NaCl. AlCl3and NOCl. AlCl3(in the last case with qualitative polarization measurements only). The preparation of pure NOCl. AlCl3is described in extenso. The properties of the compound finally obtained are different from those given in the literature. NaCl. AlCl3, has to be considered as Na+AlCl4−, and NOCl. AlCl3as NO+AlCl4−. There is a perceptible interaction between nitrosyl and the chlorines of AlCl4−in the last compound. The properties of NOCl. AlCl3are intermediate between those for a pure heteropolar compound (NO+AlCl4−) and a pure molecular compound NOCl. AlCl3, being more alike those of the heteropolar form.Force constants have been calculated for AlCl4;−, making use of theLechnerformulae and of those for aUrey‐Bradleyfield and also of those for the orbital valence force field ofHeat

ISSN:0165-0513    

DOI:10.1002/recl.19530720103

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

Abstract1,4‐Diphenyl‐1,3‐butadiene, 1,6‐diphenyl‐1,3,5‐hexatriene and 1,8‐diphenyl‐1,3,5,7‐octatetraene have each both a monoclinic and an orthorhombic modification of which lattice constants and some optic

ISSN:0165-0513    

DOI:10.1002/recl.19530720104

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

AbstractThe reactivity of 2,4,6‐tribromopyridine‐towards dilute solutions of ammonia in water and butanol is described. The rate of the substitution reaction is higher in water than in the less polar butanol. In water the reagent attacks chiefly the bromine atom at the 4‐position, where the nucleus carries the highest positive electrical charge. In butanol the replacement of the bromine atoms at the 2‐ and 6‐positions is preponderant. Together with 2‐amino‐4,6‐dibromopyridine and 4‐amino‐2,6‐dibromopyridine, which compounds were known, 2,4‐diamino‐6‐bromopyridine was isolated as a reaction product.In agreement with the above‐mentioned results 2,4‐dichloronitrobenzene reacts more quickly with ammonia in water than in ethanol. While in the latter solvent during a reaction at 140° exclusively the ortho chlorine atom is replaced, in water, in addition to 2‐amino‐4‐chloronitrobenzene, some

ISSN:0165-0513    

DOI:10.1002/recl.19530720105

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

AbstractThe relation between the stability (log k) of a metal complex in solution and the ionization potential (I) of the metal component is ascertained for a number of systems described in the literature. There proves to be a linear relation of the following form: log k = p. (I − q). The value of q is found to depend on the functional group(s) of the ligand, that of p on the number of the functional groups in the ligand and the polarizability of the ligand molecul

ISSN:0165-0513    

DOI:10.1002/recl.19530720106

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

Abstract1Pentadecanoic, heptadecanoic and nonadecanoic acid were prepared from respectively myristic, palmitic, and stearic acid by the Arndt‐Eistert synthesis. The use of the Wilds and Meader variation for the rearrangement of the alkyldiazoketones, involving heating at 180° C with octanol‐2 or benzyl alcohol and γ‐collidine, gave fairly pure fatty acids. The reaction proceeded fast, and good yields were obtained. The advantage over the conventional Ag2O‐methanol method was especially marked in the case of nonadecanoic acid.2A chromatographic procedure, using silicagel as an adsorbent, petroleum ether as a solvent, and petroleum ether plus 25% ether as an eluent, was developed. This allowed a further purification of the products to pure fa

ISSN:0165-0513    

DOI:10.1002/recl.19530720107

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

AbstractPotentials measured on plant roots in media of varying acidity reverse their sign at a certain pH usually lying in or near the range 3 to 3.5. The value of this pH depends on the plant species. The reversal is explained by the amphoteric character of the root substance. If the root substance carries more dissociated acidoid than dissociated basoid groups, the root potential, pictured as a membrane potential in a Donnan system, will be negative. If there is a surplus of basoid dissociated groups, the potential will be positive. In the intermediate case, where equal numbers of both groups are present, there is no potential because the conditions for a Donnan system are absent. Quantitatively, the electrical behaviour of the amphoteric root substance can be satisfactorily described by assuming a linear relationship between its net acid‐ or base‐binding capacity and the

ISSN:0165-0513    

DOI:10.1002/recl.19530720108

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

AbstractThe Raman spectra of solid and liquid gallium trichloride are communicated. From the number of frequency shifts found and from the frequency values it is probable that gallium trichloride is present as double molecules Ga2Cl6in the solid and in the liquid. The structure of these double molecules is probably that of the ethylenic (bridge) model as was formerly concluded for Al2Cl6etc., although the absence of polarization measurements makes this conclusion less conclusive. The result is in agreement with the crystal structure determination of Ga2Cl6as given in the Thesis ofRenes. A comparison is made between experimental and calculated frequency values for the “ethane” and the “ethylenic”

ISSN:0165-0513    

DOI:10.1002/recl.19530720109

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

AbstractOn décrit dans ce travail une méthode générale de synthèse des acides gras supérieurs dont la chaîne hydrocarbonée peut être linéaire ou ramifiée en des positions déterminées. Trois synthèses sont données en exemple: celles des acides palmitique, stéarique, et 15‐mét

ISSN:0165-0513    

DOI:10.1002/recl.19530720110

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY

摘要:

AbstractIn concentrated aqueous solution and in the presence of an excess of formaldehyde more than two methylol groups may be attached to one molecule of urea. The equilibrium constant of the formation of trimethylol urea is evaluated.

ISSN:0165-0513    

DOI:10.1002/recl.19530720111

出版商:WILEY‐VCH Verlag    

年代:1953

数据来源: WILEY