Hydrogen-bonded linear chain assemblies of palladium(ii)-selenoether complexes: solid state aggregates as templates for nano-structural Pd17Se15 leading to efficient electrocatalytic activity

A analogous series of 2-(3,5-dimethylpyrazol-1-yl)phenyl substituted selenoether complexes of palladium [PdCl2(RSeC(6)H(4)dmpz)]; (R = CH2COOH (1), CH2CH2COOH (2), and CH2CH2OH (3); dmpz = dimethyl-pyrazole) 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 (Pd17Se15) 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 (Pd17Se15) obtained from the hydrogen bonded aggregate of complex PdCl2L1 (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 CH3OH, the electrocatalytic rate constant (k) obtained was 0.3 x 10(3) cm(3) mol(-1) s(-1).

Automated summary

A series of 2-(3,5-dimethylpyrazol-1-yl)phenyl substituted selenoether complexes of palladium were synthesized and their molecular structures and aggregation were analyzed. These complexes were converted to capping free palladium selenide nanoparticles and evaluated for electrocatalytic activity in alkaline medium.