Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Zirconium(IV) chloride, also known as zirconium tetrachloride, is the inorganic compound with the formula ZrCl4. This white high-melting solid hydrolyzes rapidly in humid air. It is a key precursor to other compounds of zirconium. Unlike molecular TiCl4, solid ZrCl4 adopts a polymeric structure wherein each Zr is octahedrally coordinated. This difference in structures is responsible for the striking difference in their properties: TiCl4 is distillable, but ZrCl4 is a solid with a high melting point. In the solid state, ZrCl4 adopts a tape-like linear polymeric structure the same structure adopted by HfCl4. This polymer degrades readily upon treatment with Lewis bases, which cleave the Zr-Cl-Zr linkages.