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

Abstract

AbstractCapillary supercritical fluid chromatography with flame ionization detection has been used to test the purity of air‐sensitive organometallic compounds such as bisethenepentamethylcyclopentadienylcobalt (Cp*Co(C2H4)2), dicarbonylcyclopentadienylcobalt (CpCo(CO)2), dicarbonylpentamethylcyclopentadienylcobalt (Cp*Co(CO)2), bisethenepentamethyl cyclopentadienylrhodium (Cp*Rh(C2H4)2), bisethenecyclopentadienylrhodium (CpRh(C2H4)2), carbonyl(1,3‐dimesitylimidazol‐2‐ylidene)cyclopentadienylcobalt (CpCo(CO)(carbene)) and ethene(1,3‐dimesitylimidazol‐2‐ylidene)pentamethylcyclopentadienylrhodium (Cp*Rh(C2H4)(carbene)). A sample introduction cell was constructed for loading of 10–40 mg of the air‐sensitive compounds in 100% N2 atmosphere. The sample cell was subsequently filled with toluene or pentane and the analytes in solution were injected onto the 50 μm i.d. capillary column using a timed split injector with 60 nL loop. A nonpolar (5% phenylsiloxane/95% methyl siloxane) stationary phase was used and a mobile phase consisting of 100% CO2 with pressure programming. No signs of air‐induced decomposition of the analytes were observed and impurities down to 1% could be determined using SFC‐FID. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 156–162, 2001