Synthesis, Structure and Electrochemical Behavior of New RPONOP (R = tBu, iPr) Pincer Complexes of the Fe2+, Co2+, Ni2+ and Zn2+ ions.

Camille Lescot (1) , Solène Savourey (1) , Pierre Thuéry (1) , Guillaume Lefevre (1) , Jean Claude Berthet (1) , Thibault Cantat (1)

1 LCMCE - Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF)

The coordination chemistry of the M2+ ions of the first row elements iron, cobalt, nickel and zinc was explored with the ligands RPONOP (2,6-(R2PO)(C5H3N), R = iPr and tBu). Syntheses and characterization of the complexes Fe(RPONOP)Br2, Co(tBuPONOP)Cl2, Ni(RPONOP)I2 and Zn(RPONOP)I2 (R = tBu, iPr) are reported together with the crystal structures of Fe(RPONOP)Br2 (R = iPr and tBu), Co(tBuPONOP)Cl2, Co(iPrPONOP)Cl(m-Cl)CoCl2(THF), Ni(iPrPONOP)I2, Zn(iPrPONOP)I2 and of the oxidation product Zn[tBuP(=O)ONOP(=O)]I2 resulting from reaction with oxygen. The electrochemical behavior of the M(tBuPONOP)X2 complexes has been investigated in acetonitrile. While the nickel compound is stable, all the complexes are sensitive to dissociation of the RPONOP ligand or ligand scrambling in strongly coordinating media. Catalytic activity in formic acid dehydrogenation with TONs up to 1143 has been found for Ni(tBuPONOP)I2.

Domaines: Matériaux

Camille Lescot, Solène Savourey, Pierre Thuéry, Guillaume Lefevre, Jean Claude Berthet, et al.. Synthesis, Structure and Electrochemical Behavior of New RPONOP (R = tBu, iPr) Pincer Complexes of the Fe2+, Co2+, Ni2+ and Zn2+ ions.. Comptes Rendus. Chimie, 2016, 19, pp.57-70. ⟨10.1016/j.crci.2015.07.004⟩. ⟨cea-01289120⟩