Work

Influence of a Lanthanide Ion on the Ni Site of a Heterobimetallic 3d–4f Mabiq Complex

Year: 2020

Type: article

Abstract: This work presents the synthesis and characterization of a 3d–4f bimetallic complex based on the redox-active macrocyclic biquinazoline ligand, Mabiq. The mixed Yb–Ni complex, [(Cp*) 2 Yb(Mabiq)Ni]BArF ( 3 ), was synthesized upon reaction of [Ni II (Mabiq)]BArF ( 2 ) with (Cp*) 2 Yb II (OEt 2 ). The molecular structures of 3 and its sister complex, [(Cp*) 2 Yb(Mabiq)Ni][(Cp*) 2 Yb(OTf) 2 ] ( 1 ), confirmed the presence of a Yb(III) center and a reduced Ni–Mabiq unit. Spectroscopy (absorption and NMR), cyclic voltammetry, and magnetic susceptibility studies were employed to analyze the electronic structure of 3, which is best described by the [(Cp*) 2 Yb III (Mabiq • )Ni II ] + formulation. Notably, the ligand-centered radical is delocalized over both the diketiminate and bipyrimidine units of the Mabiq ligand. The magnetic susceptibility and variable temperature NMR studies for 3 denote coupling between the Ni–Mabiq site and the peripheral Yb center—previously unobserved in 3d–3d Mabiq complexes. The complex nature of the exchange interactions is highlighted by the multiconfigurational ground state for 3, comprising nearly degenerate singlet and triplet states.

Source: Inorganic Chemistry

DOI: 10.1021/acs.inorgchem.0c03058

Authors: Stuart A. J. Boyce, Jules Moutet, Lukas Niederegger, Thomas Simler, Grégory Nocton, Corinna R. Hess