Structural implications of the paramagnetically shifted NMR signals from pyridine H atoms on synthetic nonheme FeIV=O complexes.

摘要: Oxoiron(IV) motifs are found in important intermediates many enzymatic cycles that involve oxidations. Over half of the reported synthetic nonheme oxoiron(IV) analogs incorporate heterocyclic donors, with a majority them comprising pyridines. Herein, we report 1H-NMR studies complexes containing pyridines arranged different configurations relative to Fe = O unit and give rise paramagnetically shifted resonances differ by as much 50 ppm. The strong dependence shifts on orientation demonstrates how unpaired electronic spin density iron center affects chemical these protons.