Metal-Ligand Proton Tautomerism, Electron Transfer, and C(sp³)-H Activation by a 4-Pyridinyl-Pincer Iridium Hydride Complex.

ABSTRACT: The para-N-pyridyl-based PCP pincer proligand 3,5-bis(di-tert-butylphosphinomethyl)-2,6-dimethylpyridine (pN-^tBuPCP-H) was synthesized and metalated to give the iridium complex (pN-^tBuPCP)IrHCl (2-H). In marked contrast with its phenyl-based congeners, e.g., (^tBuPCP)IrHCl and derivatives, 2-H is highly air-sensitive and reacts with oxidants such as ferrocenium, trityl cation, and benzoquinone. These oxidations ultimately lead to intramolecular activation of a phosphino-t-butyl C(sp³)-H bond and cyclometalation. Considering the greater electronegativity of N than C, 2-H is expected to be less easily oxidized than simple PCP derivatives; cyclic voltammetry and DFT calculations support this expectation. Howe

SUBMITTER: Bhatti TM 

PROVIDER: S-EPMC10450815 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature