The mechanism of the oxidation reaction and the role of LEF: To decipher the reaction mechanism, we studied the electronic structures of all stationary species with spin doublet. As can be seen from Figure , in the free oxidant, the three unpaired electrons are populated on HM1, much the same as in the standard electronic structure of porphyrin radicalcation coupled to a triplet oxo-iron moiety to a total of a doublet spin. However, in the presence of tetralin (TLN) entrapped inside the cage, an electron is transferred from TLN (Figure )