Solid-state NMR studies of organometallics and heterogeneous catalysis

Solid-state NMR spectroscopy has been applied to the study of both organometallics and heterogeneous catalyst systems. By studying rearrangement processes of organic ligands in organometallic complexes, an understanding of the dynamic behavior of organometallic compounds can be gained. Ultimately this understanding can be applied to better understand organometallic catalysts. The sigmatropic rearrangement of sigma-bound cyclopentadiene ligands has been investigated using variable-temperature (VT) solid-state NMR spectroscopy. Another rearrangement of interest is the movement of ligands on PtPt vapochromic materials upon exposure to volatile organic compounds (VOCs). Techniques used to study fundamental issues in organometallic chemistry can also be applied to more complex systems like heterogeneous catalysis. Of specific interest is the conversion of propene to acrolein over bismuth molybdate catalysts.; Solid-state NMR has proved a valuable tool for the study of a wide variety of inorganic systems. In each study, NMR data provided unique insight into the problem. In the case of the intermolecular rearrangement of compounds of the formula Hf(eta5-C5H5)2 (eta1-C5H5)2 and Ti(eta 5-C5H5)2(eta1-C 5H5)2, the pathway of the rearrangement was followed using 2D exchange spectroscopy in the solid state. In the study of vapochromic PtPt salts, NMR directly showed interactions between solvent vapors and the ligands on the Pt centers occurs. For the partial oxidation of propene to acrolein, the fate of a 13C label on the propene was followed throughout the reaction and propene isomerization was observed. NMR spectroscopy will no doubt continue to be an important analytical tool for the investigation of inorganic systems.