A six-coordinate high-spin FeIVO species of cucurbit[5]uril: a highly potent catalyst for C-H hydroxylation of methane, if synthesised.

DFT and ab initio DLPNO-CCSD(T) calculations predict a stable S = 2 six-coordinate FeIVO species with cucurbit[5]uril (CB[5]) as a ligand ([(CB[5])FeIVO(H2O)]2+(1)). The strong oxidising capability of 1 far exceeds even that of metalloenzymes such as sMMOs in activating inert substrates such as methane, setting the stage for a new generation of biomimetic catalysts.