Chemical Properties
White powder, discolors on air exposure
Physical properties
Physical Data of BIS(CYCLOPENTADIENYL)ZIRCONIUM DIHYDRIDE: polymeric in solid and dimeric [Cp2ZrH(μ-H)]2 in benzene or toluene. The polymeric nature of [Cp2ZrH2]n is suggested by its involatility, insolubility, and insusceptibility to reaction in air. The presence of a ZrH-Zr bridging system is inferred from the intense broad IR absorption band at 1520 cm-1.
Uses
BIS(CYCLOPENTADIENYL)ZIRCONIUM DIHYDRIDE is a catalyst for hydrogenation of alkenes and alkynes in combination with hydrogen; catalyst for Meerwein-Ponndorf-Verley type reduction and Oppenauer type oxidation; catalyst for crossed-aldol condensation; catalyst for Tishchenko reaction; reducing agent for organohalogen compounds.
Uses
Bis(cyclopentadienyl)zirconium dihydride, is used as a pharmaceutical intermediate and in chemical industry.
Preparation
Preparative Methods of BIS(CYCLOPENTADIENYL)ZIRCONIUM DIHYDRIDE: the following method is convenient for the preparation of Cp2ZrH2. μ-Oxobis[chlorobis(η5-
cyclopentadienyl)zirconium] ([Cp2ZrCl]2O) is prepared by the reaction of
Dichlorobis(cyclopentadienyl)zirconium (Cp2ZrCl2), available from commercial sources, in dichloromethane and
water in aniline. To a solution of [Cp2ZrCl]2O in THF is added dropwise Lithium Aluminum Hydride in THF
with stirring under an argon atmosphere. The reaction mixture is stirred for ca. 8 h at rt, filtered, and then washed
with THF to give the Cp2ZrH2 complex as a white solid (eq 1)
[1].
storage
BIS(CYCLOPENTADIENYL)ZIRCONIUM DIHYDRIDE is photosensitive and hydrolyzed by water; should be stored in the dark under an argon atmosphere.
References
1. Wailes, P. C.; Weigold, H. Inorg. Synth. 1990, 28, 257.
