The origins of dramatic axial ligand effects: closed-shell Mn(V)O complexes use exchange-enhanced open-shell States to mediate efficient H abstraction reactions.

and nevertheless thelatter two perform the H abstraction efficiently even thoughthese states are not oxyl radicals. Moreover, the reactionseries showed almost an unprecedented axial ligand effect,X . Thus, coordination of F was found to accelerate thereaction rate with dihydroanthracene (DHA) by a factor of2100 relative to the pentacoordinate complex, and with CNas a ligand, the acceleration factor was 16000.

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