1. A 5,000-fold increase in the HAT reactivity of a nonheme FeIV=O complex simply by replacing two pyridines of the pentadentate N4Py ligand with pyrazoles.
- Author
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Pal, Nabhendu, Jin Xiong, Jahja, Mehmet, Mahri, Sami, Young Jr., Victor G., Yisong Guo, Swart, Marcel, and Que Jr., Lawrence
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IRON oxidation , *SCISSION (Chemistry) , *PYRIDINE , *PYRAZOLES , *ISOQUINOLINE - Abstract
A pentadentate [N5] ligand (N2Py2Pz) based on the classic N4Py (N,N-bis (2-pyridylmethyl)- N- bis(2-pyridyl) methylamine) framework has been synthesized by replacing the two pyridylmethyl arms with corresponding (N-methyl) pyrazolylmethyl units to form [N-bis(1-methyl- 2- pyrazolyl) methyl-N- (bis-2- pyridylmethyl) amine] (L1). The oxidation of the iron(II) precursor (N2Py2Pz)FeII(OTf)2 (1) with (tBuSO2)C6H4IO at 298 K leads to the formation of the [FeIV(O)(N2Py2Pz)]2+ intermediate (2) with a near-IR band at 750 nm (εM = 250 M-1cm-1) and a t1/2 ~ 2 min at 298 K. The introduction of the less basic pyrazolylmethyl ligands in place of two pyridylmethyl units generates FeIV=O intermediate 2 that exhibits a cyclohexane oxidation rate of 0.29 s-1 at 298 K, which is 5,000-fold faster than that observed for the classic FeIV(O)N4Py parent complex and 40,000-fold more reactive than the least reactive FeIV(O)N2Py2Q' complex in this series (Py = pyridine, Q' = isoquinoline) recently reported by Nordlander. high-valent. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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