Possible geometries and fluxional mechanisms of three ReH ₇ (NHC) ₂ complexes (NHC = IMes (1), IMesCl ₂ (2), and BIMes (3) ) are presented. A new process named “η ₂ -quadratic twist” has been identified. The complexes presented can perform C–H activation.
Grieco et al. (2025) studied this question.