|
Oxophilicity is the tendency of certain chemical compounds to form oxides by hydrolysis or abstraction of oxygen, often from organic compounds. The term is usually used to describe metal centers, commonly the early transition metals such as titanium, niobium, and tungsten. Oxophilic metals are classified as "hard" within the HSAB concept. Many main group compounds are also oxophilic, such as derivatives of aluminium, silicon, and phosphorus(V). The handling of oxophilic compounds often requires air-free techniques. ==Typical reactivity== Complexes of oxophilic metals typically are prone to hydrolysis. For example, the high valent chlorides hydrolyze rapidly to give oxides: :TiCl4 + 2 H2O → TiO2 + 4 HCl These reactions proceed via oxychloride intermediates. For example WOCl4 results from the partial hydrolysis of tungsten hexachloride. Hydroxide-containing intermediates are rarely observed for oxophilic metals. In contrast, the anhydrous halides of the later metals tend to hydrate, not hydrolyze, and they often form hydroxides. Reduced complexes of oxophilic metals tend to generate oxides by reaction with oxygen. Typically the oxide-ligand is bridging, e.g. :2 (C5H5)2TiCl + 1/2 O2 → 2O Only in rare cases do the products of oxygenation feature terminal oxo ligands.〔Nugent, W. A.; Mayer, J. M. "Metal-Ligand Multiple Bonds" J. Wiley: New York, 1988. ISBN 0-471-85440-9.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「oxophilicity」の詳細全文を読む スポンサード リンク
|