Elements of Group V and with Silicon

A thermodynamic analysis of the co-reduction of Zr02 and Si02 by carbon at 1500— 3000 K has suggested that the formation of ZrSi is more probable than that of ZrSi2-  

Zirconium(ii) and Hafnium(ii).—Studies of the diffusion coefficients of Zr dissolved in fused alkali-metal chloride melts have led to the suggestion that [ZrCl4] ions are formed. ZrAlClj has been isolated as a pure brown powder following the disproportionation of ZrClj in AICI3. 

ZrCl4 reacts over 2 h with LiPh (1 4) in Et20 at — 30 to — 40°C to afford a brown solution of ZrPh4, but evaporation of this solution affords the black crystalline product [Ph2ZrOEt2]2- This compound is spontaneously inflammable in air and produces PhZrOEt when thermally decomposed. Evidence has been presented for the formation of Xr CTijP i)2 by the thermal decomposition of Zr(CH2Ph)4.  

Zirconium(iii) and Ha ium(iii).— The complexes formed by the halides and oxyhalides of zirconium(iii) and hafnium(iii) have been reviewed. [ZrClj-(3,5-lutidine)2]2 has been prepared from its constituents and its structure is presumed to be a chloride-bridged dimer. 2,6-Lutidine does not react with ZrCl3 and 2,4-lutidine (L) affords [ZrCl3Lj (y ca. 1.1—1.33) together with a 

Smirnov, V. E. Komarov, and N. P. Borodina, Fiz. Khim. Elektrokhim. Rasplav. Solei. Shlakov, Tr. Vses. Soveshch. 4th, ed. A. V. Gorodyskii, Naukova Dumka , Kiev, 1970,2,3 Chem. Abs., 1972, 77, 92969p). 

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