Bis(cyclopentadienyl)diphenylzirconium

Abstract

[51177-89-0] C22H20Zr (MW 375.62) InChI = 1S/2C6H5.2C5H5.Zr/c2*1-2-4-6-5-3-1;2*1-2-4-5-3-1;/h2*1-5H;2*1-5H; InChIKey = PXCWOMBHWLFECP-UHFFFAOYSA-N (precursor of ‘Cp2Zr’;3,4 precursor of zirconium–benzyne complex8, 9; insertion reaction into Zr–Ph bond20) Alternate Name: diphenylzirconocene. Physical Data: mp 140 °C dec. Solubility: sol THF, CS2; appears to react with CHCl3; reacts with protic solvents. Analysis of Reagent Purity: IR (nujol cm−1) 1405(m), 1240(w), 1050(m), 1005(m), 980(m), 827(w), 820(s), 775(s), 698(s); 1H NMR (CS2) δ: 6.10(s), 6.8–7.3(m); (THF-d8) δ: 6.18, 6.93(m), 7.23 (m). Preparative Method: the reaction is conducted under an atmosphere of argon. A suspension of 1.0 g (3.4 mmol) of Dichlorobis(cyclopentadienyl)zirconium in 20 mL of diethyl ether is cooled to −40 °C. Phenyllithium (3.0 mL, 2.3 M) is subsequently added dropwise via a syringe over a 45 min period with magnetic stirring, during which time a white crystalline solid separates from solution. Stirring is continued at −40 °C for 1 h and the temperature is slowly allowed to rise to 0 °C. The solvent is then evaporated under reduced pressure and the solid residue is washed with pentane and decanted. The remaining residue is extracted with diethyl ether and the extracts are filtered under nitrogen. Concentration of the filtrate yields 1.0 g (80%) of white crystalline Cp2ZrPh2.2 Purification: recrystallization at low temperature from diethyl ether; cannot be sublimed. Handling, Storage, and Precautions: appears to be more stable than the dimethyl analog toward air and moisture. Use in a fume hood.