Preparation of Halide Compounds of Inert Gases

In their preliminary communication, Antropoff, Weil, and Frauenhof present the results of experiments on the preparation of chemical compounds of the inert gases. The probability of obtaining stable compounds is greatest for inert gases with high atomic weight, on the one hand, and with halogens, on the other. Indeed, when a mixture of krypton and chlorine was passed through a tube in which an intense electric discharge was produced, and then through a trap cooled with liquid air, the latter, in addition to solid chlorine, yielded a solid dark-red substance, which was more volatile than solid chlorine and therefore readily separable from it. Simultaneously with the formation of this substance, a decrease in the pressure of krypton in the apparatus occurred. The compound of krypton with chlorine obtained is so stable that it can be kept for many days at room temperature, again giving a red substance on cooling. Under the action of heated calcium this compound decomposes, liberating krypton. The spectrum of chlorokrypton vapor is banded. In analogous experiments, a mixture of krypton with bromine also gave a decrease in pressure. A mixture of xenon with chlorine produced no decrease in pressure. (A. V. Antropoff, K. Weil u. Frauenhof, “Naturwiss.”, H. 37, 688, 1932.)

B. Klyarfeld