THIOETHER-COORDINATED NICKEL OXIDATION-STATES - A NI(III)S2N4 FAMILY INCORPORATING HEXADENTATE THIOETHER-AZO-OXIME CHELATION

The isolation of the first family of thioether-coordinated nickel(III) complexes, [Ni(RxL)]PF6, incorporating acyclic ligands has been achie ved using thioether-azo-oximes of the type HON=C(R)N=NC6H4S(CH2)(x)- S C6H4N=NC(R)=NOH (H2RxL, x = 2, 3; R =: Ph, a-naphthyl). The synthesis consists of electrooxidation of Ni-II(RxL) precursors having proven Ni S2N4 coordination spheres. The [Ni(RxL)](+) species have a d(z)(2) gro und state and display azo-N-14 superhyperfine EPR splitting. The nicke l(III) state is stabilized well, the nickel(III)-nickel(II) reduction potential being relatively low.