The hydrogen-bonding dynamics of water to a nitrile-functionalized electrode is modulated by voltage according to ultrafast 2D IR spectroscopy.

ABSTRACT: We report the hydrogen-bonding dynamics of water to a nitrile-functionalized and plasmonic electrode surface as a function of applied voltage. The surface-enhanced two-dimensional infrared spectra exhibit hydrogen-bonded and non-hydrogen-bonded nitrile features in similar proportions, plus cross peaks between the two. Isotopic dilution experiments show that the cross peaks arise predominantly from chemical exchange between hydrogen-bonded and non-hydrogen-bonded nitriles. The chemical exchange rate depends upon voltage, with the hydrogen bond of the water to the nitriles breaking 2 to 3 times slower (>63 vs. 25 ps) under a positive as compared to a negative potential. Spectral diffusion created by hydrogen-bond fluctuations occurs on a ~1 ps timescale and is moderately potential-dependent.

SUBMITTER: Ryan MJ 

PROVIDER: S-EPMC10756189 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature