1H bridging and terminal hydride T1 values. Comments on classical vs non‐classical hydride identification using T1 criteria

Hydride 1H T1 values are reported for a selected series of ruthenium, iridium and platinum complexes. These T1 values range from 6.9 to 0.05 s with the shortest value, 0.05 s, assigned to a complex containing both hydride and coordinated molecular hydrogen, i.e. “M(H2)”. There are nuclear Overhauser enhancements arising both from protons on coordinated ligands and other hydride ligands. It is suggested that the molecular weight of the complex and the measurement conditions can be important factors for T1.