The mass-spectrometric determination of 34S/32S ratios in natural materials is most commonly done with sulfur dioxide. The standard technique for the preparation of sulfur dioxide from sulfides or native sulfur consists of their combustion in a stream of oxygen at temperatures between 900 and 1350 °C (1-3). This technique allows the almost total recovery of the sulfur in the form of sulfur dioxide and, therefore, has been accepted by most laboratories. However, this conversion is not carried out under vacuum, and contamination of the sulfur dioxide by atmospheric gases of impure oxygen is possible. To overcome this disadvantage and to have another independent method, a technique for the conversion of sulfides into hexafluorides has been developed (4, 5). This technique permits the handling of extremely small samples, but its disadvantage lies in the use of extremely reactive fluorinating agents.

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Alkyl‐bis(dimethylamino)((dimethylamino))borane erhält man bei der Dimethylaminolyse von Alkylbordichloriden oder bei der Alkylierung von Bis(dimethylamino)‐chloroboran mit Alkyl‐Lithium. Ihr Verhalten gegenüber den Halogenwasserstoffen HCl, HBr und HJ wurde untersucht.

Norh und Regnet [I] beschrieben kurzlich das erste Derivat des 1.3.4-Triaza-2.5-diborolidins. Dieser funfgliedrige Bor-Stickstoff-Heterocyclus entsteht bei der Aminolyse eines