Continuous tubular flow reactor for XAFS studies of organometallic reactions: Possibilities and limitations for studies of the Soai reaction

A computer-controlled continuous tubular flow reactor system has been commissioned that permits time-resolved in situ XAFS measurements of organometallic reactions. The system was commissioned by Zn K-edge measurements of products formed during the Soai reaction. XANES data are shown that illustrate the quality of the data that can be achieved. The XANES spectra are compatible with the presence of dimer, trimer or other oligomeric alkoxide species in the Soai process. It is shown how heterogeneity in the Soai reaction system leads to considerable complications with the measurements due to the formation of floating particles of the aldehyde/iPr₂Zn adduct formed in the reaction; additionally, decomposition of iPr₂Zn with residual air and moisture leads to deposits on cell walls.