Hydrogen-bonded linear chain assemblies of palladium(II)-selenoether complexes: solid state aggregates as templates for nano-structural Pd 17 Se 15 leading to efficient electrocatalytic activity.

A analogous series of 2-(3,5-dimethylpyrazol-1-yl)phenyl substituted selenoether complexes of palladium [PdCl 2 (RSeC 6 H 4 dmpz)]; (R = CH 2 COOH (1), CH 2 CH 2 COOH (2), and CH 2 CH 2 OH (3); dmpz = dimethylpyrazole) were ably synthesized in a facile manner and exhaustively characterized. Insight into molecular structures of these complexes was keenly probed through single crystal X-ray diffraction (XRD) analysis, unfolding the structural scaffolds and laying into molecular aggregation, availed through hydrogen bonding interactions borne out of tethered protic groups. The complexes were converted to capping free palladium selenide (Pd 17 Se 15 ) nanoparticles through pyrolysis and evaluated for their electrocatalytic efficacy towards the hydrogen evolution reaction (HER), the oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) in alkaline medium. In an alkaline medium, PSNP1 (Pd 17 Se 15 ) obtained from the hydrogen bonded aggregate of complex PdCl 2 L 1 (1) produced good HER activity. PSNP1 had a little decrease in current density after 300 continuous cycles, which proves that the catalyst presents high stability in the recycling process. For the electrocatalytic oxidation of CH 3 OH, the electrocatalytic rate constant ( k ) obtained was 0.3 × 10 3 cm 3 mol -1 s -1 .