Hydrogen-bonding effects on the reactivity of [X-Fe(III)-O-Fe(IV)═O] (X = OH, F) complexes toward C-H bond cleavage.

ABSTRACT: Complexes 1-OH and 1-F are related complexes that share similar [X-Fe(III)-O-Fe(IV)═O](3+) core structures with a total spin S of ½, which arises from antiferromagnetic coupling of an S = 5/2 Fe(III)-X site and an S = 2 Fe(IV)═O site. EXAFS analysis shows that 1-F has a nearly linear Fe(III)-O-Fe(IV) core compared to that of 1-OH, which has an Fe-O-Fe angle of ~130° due to the presence of a hydrogen bond between the hydroxo and oxo groups. Both complexes are at least 1000-fold more reactive at C-H bond cleavage than 2, a related complex with a [OH-Fe(IV)-O-Fe(IV)═O](4+) core having individual S = 1 Fe(IV) units. Interestingly, 1-F is 10-fold more reactive than 1-OH. This raises an interesting question about what gives rise to the reactivity difference. DFT calculations comparing 1-OH and 1

SUBMITTER: Xue G 

PROVIDER: S-EPMC3632308 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature