Synthesis, Structural, and Electrocatalytic Reduction Studies of [Pd(P2N2)2]2+ Complexes

A series of four new bis-P2N2 (P2N2 = 1,5-diaza-3,7-diphosphacyclooctane) Pd(II) complexes were synthesized and characterized by spectroscopy, electrochemistry, and X-ray crystallography. The compounds crystallize in square planar or tetrahedrally distorted geometries and exhibit a single quasi-reversible 2e– Pd(II/0) redox couple in voltammetric studies. [Pd(PPh 2NBn 2)2]2+ and [Pd(PMe 2NPh 2)2]2+ were tested for electrochemical CO2 reduction in the presence of excess protons and found to preferentially produce H2.