|
In organometallic chemistry, bent metallocenes are a subset of metallocenes. In bent metallocenes, the ring systems coordinated to the metal are not parallel, but are tilted at an angle. A common example of a bent metallocene is Cp2TiCl2. Several reagents and much research is based on bent metallocenes. ==Synthesis== Like regular metallocenes, bent metallocenes are synthesized by a variety of methods but most typically by reaction of sodium cyclopentadienide with the metal halide. This method applies to the synthesis of the bent metallocene dihalides of titanium, zirconium, hafnium, and vanadium: :2 NaC5H5 + TiCl4 → (C5H5)2TiCl2 + 2 NaCl In the earliest work in this area, Grignard reagents were used to deprotonate the cyclopentadiene. Niobocene dichloride, featuring Nb(IV), is prepared via a multistep reaction that begins with a Nb(V) precursor: :NbCl5 + 6 NaC5H5 → 5 NaCl + (C5H5)4Nb + organic products :(C5H5)4Nb + 2 HCl + 0.5 O2) → ()Cl2 + 2 C5H6 :2 HCl + ()Cl2 + SnCl2 → 2 (C5H5)2NbCl2 + SnCl4 + H2O Bent metallocene dichlorides of molybdenum and tungsten are also prepared via indirect routes that involve redox at the metal centres. TebbeRgt.png|Tebbe's reagent Schwartz's Reagent.png|Schwartz's reagent. Petasis_Reagent.png|Petasis reagent Cp2Ti(CO)2.png|Titanocene dicarbonyl. 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「bent metallocene」の詳細全文を読む スポンサード リンク
|