Abstract
The new biomimetic ligands N4Py2Ph (1) and N4Py2Ph,amide (2) were synthesized and yield the iron(II) complexes [FeII(N4Py2Ph)(NCCH3)](BF4)2 (3) and [FeII(N4Py2Ph,amide)](BF4)2 (5). Controlled orientation of the Ph substituents in 3 leads to facile triplet spin reactivity for a putative FeIV(O) intermediate, resulting in rapid arene hydroxylation. Addition of a peripheral amide substituent within hydrogen-bond distance of the iron first coordination sphere leads to stabilization of a high-spin FeIIIOOR species which decays without arene hydroxylation. These results provide new insights regarding the impact of secondary coordination sphere effects at nonheme iron centers.
Highlights
We report the synthesis of two new polydentate ligands, N4Py2Ph (1) and N4Py2Ph,amide (2) (N4Py = N,N-bis(2pyridylmethyl)-N-bis(2-pyridyl)methylamine) (Figure 1), which have been designed to examine second-coordination sphere effects in nonheme Fe model complexes
An iron(II) complex from 1 undergoes rapid, regioselective arene hydroxylation at one Ph ring, and a novel reaction channel appears accessible by the positioning of the phenyl ring in the second coordination sphere
The FeII complex from 2 does not undergo arene hydroxylation but rather leads to the formation of a metastable FeIII-OOR complex. The latter result suggests a significant influence of the amide-derived H-bond donor group on the stability of the FeIIIOOR species
Summary
We report the synthesis of two new polydentate ligands, N4Py2Ph (1) and N4Py2Ph,amide (2) (N4Py = N,N-bis(2pyridylmethyl)-N-bis(2-pyridyl)methylamine) (Figure 1), which have been designed to examine second-coordination sphere effects in nonheme Fe model complexes. An iron(II) complex from 1 undergoes rapid, regioselective arene hydroxylation at one Ph ring, and a novel reaction channel appears accessible by the positioning of the phenyl ring in the second coordination sphere.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
