Purity testing of air-sensitive organometallic compounds by capillary supercritical fluid chromatography

Capillary supercritical fluid chromatography with flame ionization detectio n has been used to test the purity of air-sensitive organometallic compound s such as bisethenepentamethylcyclopentadienylcobalt (Cp*Co(C2H4)(2)), dica rbonylcyclopentadienylcobalt (CpCo(CO)(2)), dicarbonylpentamethylcyclopenta dienyl cobalt (Cp*Co(CO)(2)), bisethenepentamethyl cyclopentadienylrhodium (Cp*Rh(C2H4)(2)), bisethenecyclopentadienylrhodium (CpRh(C2H4)(2)), carbony l( 1,3-dimesitylimidazol-2-ylidene)cyclopentadienylcobalt (CpCo(CO)carbene) ) and ethene(1,3-dimesitylimidazol-2-ylidene)pentamethylcyclopentadienylrho dium (Cp*Rh(C2H4)(carbene)). A sample introduction cell was constructed for loading of 10-40 mg of the air-sensitive compounds in 100% N-2 atmosphere. The sample cell was subsequently filled with toluene or pentane and the an alytes in solution were injected onto the 50 mum i.d. capillary column usin g a timed split injector with 60 nL loop. A nonpolar (5% phenylsiloxane/95% methyl siloxane) stationary phase was used and a mobile phase consisting o f 100% CO2 with pressure programming. No signs of air-induced decomposition of the analytes were observed and impurities down to 1% could be determine d using SFC-FID. (C) 2001 John Wiley & Sons, Inc.