Zirconium powder pattern

The melting point of pure zirconium trichloride could not be obtained because of disproportionation. Attempts to determine the phase diagram for the sodium chloride system failed because of excessive disproportionation. In the potassium chloride-zirconium trichloride system the eutectic temperature was 581° 2°C. A mixed system was used, however, since it was found that the stability of the trichloride was satisfactory in a 50 50 sodium chloride potassium chloride melt. Powder patterns of the frozen melt at 15 mole% zirconium trichloride which had been at 750°C for 24 hours showed no evidence of the dichloride and tetrachloride. There was evidence for slight solubility of the trichloride in the solid at this composition. The reaction of zirconium metal with the trichloride in the equimolar sodium-potassium chloride melt revealed that even after the trichloride had been reduced to the dichloride, zirconium metal dissolved to the extent of 5 x lO" or 10 mole fraction of excess metal in the solution. Zirconium metal did not, however, appear to dissolve in the melt in the absence of zirconium dichloride. 

The Zr SSNMR spectrum of bis(indenyl)zirconium dichloride, [Ind2ZrCl2], was significantly broadened (Cq 31 MHz) due to a distribution of Zr—C bond lengths the unexpected presence of an additional Zr powder pattern was attributed to possible polymorphism within the sample... 

Structural Studies. X-ray powder diffraction patterns for I indicate that the crystal structure is isomorphous to Zr2(0H)2-(SOO3 (H20)>. Figure 1 depicts the structure of the zirconium compound (5). The structure of I is identical to that of the zirconium analog except for variations in bond distances and angles which do not affect the overall structure. We have as yet been unable to obtain single crystals of I which are suitable for X-ray diffraction studies. 

The plutonium-bearing precipitate obtained from nitric acid solutions (containing molybdenum, zirconium and plutonium) gives an X-ray powder diffraction pattern not distinguishable from that of ZrMo207(0H)2(H20)2 precipitated without plutonium. However, since the Pu content is low, the Pu could be present either in the Pu molybdate structure or replacing Zr in the Zr molybdate structure and not be detected in the X-ray patterns. 

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