om8b00559_si_001.xyz (20.79 kB)
Redox Series of Cyclometalated Nickel Complexes [Ni((R)Ph(R′)bpy)Br]+/0/–/2– (H–(R)Ph(R′)bpy = Substituted 6‑Phenyl-2,2′-bipyridine)
dataset
posted on 2018-09-14, 13:21 authored by Aaron Sandleben, Nicolas Vogt, Gerald Hörner, Axel KleinNew
organonickel complexes [Ni((R)Ph(R′)bpy)Br] carrying
various substituted derivatives of the tridentate –C∧N∧N ligand 6-(phenyl-2-ide)-2,2′-bipyridine
(−Phbpy) were synthesized from the precursor [Ni(COD)2] (COD = 1,5-cyclooctadiene) and the protoligands (ligand
precursors) Br–(R)Ph(R′)bpy. Several synthetic routes
for the protoligands were studied and compared. All new compounds
have been analyzed and spectroscopically characterized. From several
complexes crystal and molecular structures were obtained from XRD
experiments. UV–vis absorption spectroscopy and detailed electrochemical
measurements reveal the impact of the various substituents on the
electronic structure of the complexes. Quantum chemical DFT calculations
illustrate the composition of highest occupied molecular orbitals
(HOMO) and lowest unoccupied molecular orbitals (LUMO) and support
the assignment of the single-electron reduction and oxidation products
as bpy-localized ligand radical species and transient nickel(III)
intermediates, respectively.