Trends in NMR chemical shifts of d0 transition metal compounds

NMR chemical shifts of (Left) single-bonded complexes and (Right) double-bonded complexes. NMR chemical shifts of d0, first-, second- and third-row transition metal compounds show two unique trends for single-bonded and multiple-bonded ligands, respectively. Scandide (d-block) and lanthanide (f-block) contractions and relativistic effects are believed to contribute to the NMR shifts, leading to the observed trends.173