Synthesis, Structural, and Electrocatalytic Reduction Studies of [Pd(P 2 N 2 ) 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((P2N2Bn)-N-Ph)(2)](2+) and [Pd((P2N2Ph)-N-Me)(2)](2+) were tested for electrochemical CO2 reduction in the presence of excess protons and found to preferentially produce H-2.