Assembly of a trapped valent CeIII/IV–TCNQ complex through metal–ligand redox cooperativity

Abstract

Complex (Cp₃Ce^IV)₂(TCNQ)(Ce^IIICp₃)₂ (1) was prepared by reducing neutral TCNQ⁰ (tetracyanoquinodimethane) with Cp₃Ce(THF). Two types of cerium centres with a dianionic TCNQ²⁻ moiety are present in 1, wherein each of the four cyano-groups are bound by a cation. Formation of this trapped-valent organocerium compound 1 is facilitated by metal–ligand redox cooperativity. Characterization of 1 was carried out using structural-, magnetometry-, and IR-spectroscopic analyses. Photophysical studies on this compound reveal Ce^III luminescence, and opens up avenues for promising multifunctional, mixed-valent lanthanide materials.