Бис (циклопентадиенил) цирконий дихлорид

Описание

Bis(cyclopentadienyl)zirconium(IV) Dichloride or zirconocene dichloride is one of numerous organo-metallic compounds (also known as metalorganic, organo-inorganic and metallo-organic compounds) sold by American Elements under the trade name AE Organo-Metallics^TM. As is the case for other transition metal metallocenes, bis(cyclopentadienyl)zirconium(IV) dichloride is most often used as a catalyst.

Химические свойства

Bis(cyclopentadienyl)zirconium dichloride is a white crystals. Soluble in polar organic solvents. Stable in dry air, very slowly hydrolyzes in moist air.

Использование

Bis(cyclopentadienyl)zirconium dichloride is used for for Stereoselective Glycosidation. It is also used in the catalyzed transamidation of primary amides with amines. Zirconocene dichloride can also be used to prepare the Negishi reagent,in oxidative cyclisation reactions. Other applications include it is used to promote greener amidations of carboxylic acids and amines in catalytic amounts. This technology avoids the requirement of preactivation of the carboxylic acid or use of coupling reagents.

Подготовка

Synthesis of zirconium dichlorodichloride
A stirring magnet was placed in a 500 mL three-necked flask, fitted with a constant pressure dropping funnel and reflux condenser, evacuated, and replaced with pure nitrogen three times. The flask was added with 50mL of toluene and 22.3g (0.1mol) of ZrCl4, and the suspension was made by turning on the stirring. Add the THF solution of sodium cyclopentadienylide to a constant pressure dropping funnel, add dropwise at room temperature, keep the reaction solution slightly boiling, after the dropwise addition, continue the reaction for 2h. Under the heating of oil bath at 50℃, evaporate the solvent under reduced pressure to obtain a yellow solid. Put the solid into a soxhlet extractor and extract with CHCl3. Most of the solvent in the extract was evaporated under reduced pressure, and the solid was precipitated after cooling and filtered. The product was washed with a small amount of CHCl3 and dried under vacuum, yielding 20.2g of white crystals, 69% yield.

Общее описание

This product has been enhanced for catalytic efficiency.

Реакции воздуха и воды

Bis(cyclopentadienyl)zirconium dichloride is extremely unstable when exposed to air. Decomposes in water .

Профиль реактивности

Bis(cyclopentadienyl)zirconium dichloride is incompatible with water, acids, bases, alcohols and halogens.

Опасность

Toxic by inhalation and skin contact, irritant to eyes and mucous membranes.

Пожароопасность

Flash point data for Bis(cyclopentadienyl)zirconium dichloride are not available, but Bis(cyclopentadienyl)zirconium dichloride is probably combustible.

Профиль безопасности

Poison by intraperitoneal route. Mutation data reported. When heated to decomposition it emits toxic fumes of Zr and Cl-.

Методы очистки

Recrystallise the dichloride from CHCl3 or xylene and dry it in a vacuum. 1H NMR (CDCl3) : 6.52 from Me4Si. Store it dry in the dark under N2. [Reid et al. Aust J Chem 18 173 1965, Beilstein 16 IV 1770.]