Redox Non-Innocence of Thioether Crowns: Spectroelectrochemistry and Electronic Structure of Formal Nickel(III) Complexes of Aza–Thioether Macrocycles

The Ni^II complexes [Ni([9]aneNS₂-CH₃)₂]²⁺ ([9]aneNS₂-CH₃=N-methyl-1-aza-4,7-dithiacyclononane), [Ni(bis[9]aneNS₂-C₂H₄)]²⁺ (bis[9]aneNS₂-C₂H₄=1,2-bis-(1-aza-4,7-dithiacyclononylethane) and [Ni([9]aneS₃)₂]²⁺ ([9]aneS₃=1,4,7-trithiacyclononane) ... X-ray structure of [Ni^III([9]aneNS₂-CH₃)₂](ClO₄)₆⋅(H₅O₂)₃ reveals an octahedral ... multi-frequency X-, L-, S-, K-band EPR spectra of the 3+ cations  reveals delocalisation of charge onto the S-thioether centres. EPR spectra for [⁶¹Ni([9]aneS₃)₂]³⁺ are consistent with a dynamic Jahn–Teller distortion in this compound.