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

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*)₂Yb(Mabiq)Ni]BArF (3), was synthesized upon reaction of [Ni^II(Mabiq)]BArF (2) with (Cp*)₂Yb^II(OEt₂). The molecular structures of 3 and its sister complex, [(Cp*)₂Yb(Mabiq)Ni][(Cp*)₂Yb(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*)₂Yb^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.

SUBMITTER: Boyce SAJ

PROVIDER: S-EPMC7116554 | biostudies-literature |

REPOSITORIES: biostudies-literature

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