Disproportionation of Tungsten Subchlorides

Abstract

To clarify the disproportionation of tungsten subchlorides in detail, the behavior of tungsten dichloride and tungsten tetrachloride on heating in. an argon atmosphere was examined by thermal gravimetric, differential thermal and X-ray analyses. The behavior of the tungsten subchloride which was obtained by heating tungsten tetrachloride at 380° C in an argon atmosphere, and might be represented by an empirical formula of WCl2.6, was also examined. TGA and DTA curves of the dichloride on heating are shown in Fig.1. The dichloride begins to disproportionate to tungsten and the gaseous tetrachloride at about 505° C. TGA and DTA curves of the WCl2.6 which was newly found to exist in this work are shown in Fig.4. The WCl2.6 begins to disproportionate to the dichloride and the gaseous pentachloride at about 395° C. Then the dichloride formed disproportionates in the same way as described above. TGA and DTA curves of the tetrachloride on heating are shown in Fig.2. The tetrachloride begins to disproportionate to the WCl2, 6 and the gaseous pentachloride at about 295° C. Subsequently, the WCl2.6 formed disproportionates to form the dichloride. Then the dichloride formed disproportionates in the same way as described above. X-ray diffraction data of WCl2.6 are also shown in Table 1.