Dioxygen oxidation of hydrocarbons by a methane monooxygenase-like system:diiron complex-O-2-Zn/HOAc-MV2+

The activation of dioxygen and incorporation into hydrocarbons have been ac hieved under mild conditions by a methane monooxygenase (MMO)-like system u sing a dinuclear iron complex [Fe(2)Dhist(OAc)(2)]BPh4. 3H(2)O as the model complex, zinc powder as the electron donor, HOAc as the proton source and methylviologen as the electron transfer agent. The results show that styren e is oxygenated predominantly to styrene oxide (1396 mol/100 mol of the Fe- 2 complex), benzaldehyde (16160) and acetophenone (986), and cyclohexane to cyclohexanol (9370) and cyclohexanone (2670). EPR studies indicate that th e hypervalent ironoxo spiecs (FeFeIV)-Fe-IV=O, derived from Fe-III Fe-III c ore via reduction, O-2-binding and protonation, is the active intermediate which inserts the activated oxygen atom into C=C or C-H bond giving each pr oduct. The system closely resembles MMO and its close relative hemerythrin in the aspects of reaction phenomena, EPR characteristics and product distr ibutions. The Mn-2 analog complex, Fe-Zn heterodinuclear complex and mononu clear iron complex show no catalytic activity, indicating that dinuclear ir on core is indespansable to catalytic activity.