Bormonoxyd

THE PLANT SULFOLIPID. IDENTIFICATION OF 6-SULFO-QUINOVOSE1

“…We wish to report the synthesis of ¿Z-matridine, I, a reduction product of matrine,1 II, the principal alkaloid of Sophora flavescens Ait. 2 The relative stereochemistry as represented in I and II has been established by several groups of and is confirmed by the synthetic route herein reported. This route is an extension of the method we reported earlier5 for the synthesis of hexahydrojulolidine which utilizes as an important step the bis alkylation of enamines with acrylonitrile after the method of Stork.6…”

Methods of Preparation of Amorphous Boron

“…Only at 1900-2000oC is it possible to achieve a product containing 99.5-99.8% boron. That is comparable to the degree of purification obtained in the best samples using other methods (ZINTL et al, 1940;MARKOVSKII et al, 1955;HAAG, 1957;SWIFT and WHITE, 1957). Floating with oleic acid in a water medium may be used to remove some impurities such as boron carbide, iron, etc., from boron (SCHAEFFER and SCHMIDT 1964;.…”

Invariability of the a-Parameter of Certain Salts with Change in Solvent

“…For many years prior to 1955 the most widely used theoretical expression for the relation between the dissociation constant of a salt in any solvent (of sufficiently low dielectric constant), the temperature, the dielectric constant of the solvent and the interionic distance in associated ion pairs (viz., the a-parameter) was that derived by Bjerrum. 3 As pointed out by Harned and Owen4 "the most noteworthy shortcoming of the Bjerrum model is its inability to follow the variation in the dissociation constant K with the dielectric constant D of the solvent without sometimes requiring highly specific dependence of the a-value upon the solvent." Some examples of this anomalous dependence of the a-parameter of a salt on the solvent are listed in a recent résumé of this subject by Kraus.…”

“…In Ka = In (4 3/3000) + S/aDkT (3) where 7 is Avogadro's number. It may be noted that in the derivation of this equation, as in that of equation 2, the predominant force considered to be operative in determining the stability of the associated ion pair is that due to charge-charge interaction.…”