⁹⁹Ru Solid-State Nuclear Magnetic Resonance Spectroscopy of Organometallic Compounds: Linking Nuclear Magnetic Resonance Parameters with Metal-Ligand Bonding

This study introduces ⁹⁹Ru solid-state NMR (SSNMR) spectroscopy, along with relativistic density functional theory (DFT) calculations of ⁹⁹Ru chemical shift and electric field gradient (EFG) tensors and their analysis with localized molecular orbitals, as a versatile tool to elucidate relationships between SSNMR spectra and Ru-ligand bonding in organometallic compounds. ⁹⁹Ru is a very challenging target for analysis by SSNMR. Robust experimental protocols were developed for the acquisition of ultrawideline ⁹⁹Ru SSNMR spectra for stationary samples with unprecedented signal-to-noise ratios and uniformity. The ⁹⁹Ru EFG and chemical shift tensors determined from these spectra are complemented by DFT-based analyses of the contributions of individual bond-, lone-pair-, and core-shell-orbitals to the NMR interaction tensors, which highlight their relationships with Ru-ligand bonding and electronic structure. These experimental and computational protocols are anticipated to prove fruitful for the characterization of a wide range of Ru-containing compounds, with applications to catalysis, advanced materials, and electronic devices.