Structure and Surface Behavior of Rh Complexes in Ionic Liquids Studied Using Angle-Resolved X-ray Photoelectron Spectroscopy

We present an ARXPS study on the surface composition and interfacial behavior of commercial [Rh(COD)2][TfO] in [C2C1Im][TfO], [C4C1Im][TfO], [C8C1Im][TfO], [C2C1Im][EtOSO3]. The complex was found to be non-intact a solution these ILs through loss COD ligands, accompanied by depletion metal center from IL/vacuum interface. Increasing chain length aliphatic substituent imidazolium cation [TfO]−-based led more pronounced interface, due higher affinity solvent cations with longer alkyl chains. ligands offered facile situ ligand substitution surface-active TPPTS afford moderate increase concentration Rh. propose formation Schrock−Osborn-type catalyst [Rh(COD)(TPPTS)2][TfO]. Information targeted design gas/IL interface is highly relevant for applications IL-based catalytic systems, such as supported ionic liquid phase (SILP) catalysis.