ペンタクロロタンタル(V)

使用Tantalum(V) chloride is used in the preparation of catalyst for the polycyclotrimerizations of alkenediynes, chloro-aryloxide compounds and for the plasma-enhanced atomic layer deposition of tantalum nitride films. It acts as a starting material for new edge-bridged octahedral M6 cluster compounds. It is involved in the preparation of tantalum(V) oxychloride, tantalum pentoxide. It is electrophilic and behaves like a Friedel-Crafts type catalyst, similar to aluminum(III) chloride.

Tantalum pentachloride, TaCl5, forms strongly hydroscopic, needle-shaped white crystals. It is produced on an industrial scale in large tonnage by the chlorination of tantalum scrap or ferrotantalum with NaFeCl4 or by the reductive chlorination of natural ores or synthetic raw materials. High purity TaCl5 is hydrolyzed with steam and thus converted to Ta2O5 of the highest purity. The reduction of TaCl5 with Mg or Al was repeatedly attempted but this thermite-type process never attained any industrial application. TaCl5 is soluble in absolute alcohol, forming the corresponding alkoxides. The alkoxides as well as the chlorides are suitable products for the deposition of tantalum or tantalum pentoxide layers.

純化方法Purify it by sublimation in a stream of Cl2. It forms colourless needles when pure (yellow when contaminated with even less than 1% of NbCl5). It is sensitive to H2O; even in conc HCl it decomposes to tantalic acid. It is soluble in EtOH. [Rolsten J Am Chem Soc 80 2952 1958, Brauer in Handbook of Preparative Inorganic Chemistry (Ed Brauer) Academic Press Vol II p 1302 1965.]