Addition Compounds of Zirconium Chloride

Like other metalloidal chlorides, zirconium tetrachloride forms various addition compounds with ammonia, phosphorus pentachloride, etc.

According to Matthews, the solid tetrachloride combines at ordinary temperature with 2 molecules of ammonia, at higher temperature with 4 molecules, and in ethereal solution yields with ammonia the compound ZrCl₄.8NH₃. Stahler and Denk, however, obtained ZrCl₄.8NH₃ by passing ammonia over zirconium tetrachloride at atmospheric temperature as long as increase in weight occurred. The product was a loose white powder, which easily lost ammonia, and with water produced zirconium hydroxide and ammonium chloride. At a higher temperature the product corresponded approximately to ZrCl₄.NH₃.

With phosphorus pentachloride the complex 2ZrCl₄.PCl₅ is formed as a white mass melting at 240° C. and boiling at 325° C. The following addition and substitution organic compounds are known:

ZrCl₄.2C₆H₅COOC₂H₅, ZrCl₂(OC₆H₄COOC₂H₅)₂, ZrCl₂(OC₆H₄COOCH₃)₂, ZrCl₂(OC₆H₄CHO)₂, ZrCl₂(C₆H₅COO)₂.