Redox-active Phosphorus Ligands Bearing an Fe4C4-core Substituent. Complexation with Palladium and Platinum

摘要

Design of ancillary ligands is crucial for developing efficient catalysis of transition metal complexes. Introduction of a redox-active functionality into ligand frameworks enables alternation of reactivity and selectivity of metal centers through chemical or electrochemical modification of redox states. Wrighton et al. reported a representative example using a 1,1'-bis(diphenylphosphino)cobaltocene-coordinated rhodium(I) complex, which switches catalytic activities toward hydrosilylation and hydrogenation upon redox change of cobaltocene moiety. Considering multiple redox ability of polymetallic species, it is expected that introduction of such frameworks provides a new type of ligand capable of multistep tuning of catalytic property. Herein, we report the synthesis and property of a redox active-phosphorus ligand bearing an Fe4C4-core substituent. Its complexation with Pd(II) and Pt(II) will also be described.