Density Functional Characterization of the Chemoselective Oxidation of Catechol by using Molecular Oxygen:Thermodynamics of the Reaction between [(triphos)Ir(dtbc)]~+ and O-2

摘要

The catalytic mechanism of intra and extra catechol cleavind dioxygenases os still a matter of debate because the intermedicat transient oxygen adduct has never been isolated in these enzymes The complex [(triphos)Ir(dtbc)]~+ (triphos=MeC(CH_2PPh_2)_3 DBTC~2-=3,5-di-tert-butylactecholate0 reacts with molecular oxygen and exhibits a ring-cleaving atalytic activity and a stable oxygen intermediatte appears this stmulates an ipportunity for obtaining information that can be transferable to the abovementioned enzymatic actalytic centres therefore giveing a breakthrough into the strategy of oxygen activion in theese natural systems Here we present the results of our compuatinal approach based on density functional theory focusing on the following aspects to explain the interaction with molecular oxygen and how to avoid the eisting spin prroblem to understand the formation of the bridging moiety to clarify if any the possible influence on the structure of the formed adduct of the bidentate versus monodentate binding of the catechol liand and to disclose eventually thnature of final decomposition products with the aim to ratioalize the intra versus extracleavage of the catechol molecule itself.