TY  - JOUR
A1  - Vaz da Cruz, Vinicius
A1  - Büchner, Robby
A1  - Fondell, Mattis
A1  - Pietzsch, Annette
A1  - Eckert, Sebastian
A1  - Föhlisch, Alexander
T1  - Targeting individual tautomers in equilibrium by resonant inelastic X-ray scattering
JF  - The journal of physical chemistry letters
N2  - Tautomerism is one of the most important forms of isomerism, owing to the facile interconversion between species and the large differences in chemical properties introduced by the proton transfer connecting the tautomers. Spectroscopic techniques are often used for the characterization of tautomers. In this context, separating the overlapping spectral response of coexisting tautomers is a long-standing challenge in chemistry. Here, we demonstrate that by using resonant inelastic X-ray scattering tuned to the core excited states at the site of proton exchange between tautomers one is able to experimentally disentangle the manifold of valence excited states of each tautomer in a mixture. The technique is applied to the prototypical keto-enol equilibrium of 3-hydroxypyridine in aqueous solution. We detect transitions from the occupied orbitals into the LUMO for each tautomer in solution, which report on intrinsic and hydrogen-bond-induced orbital polarization within the pi and sigma manifolds at the proton-transfer site.
KW  - Equilibrium
KW  - Molecular structure
KW  - Molecules
KW  - Nitrogen
KW  - Solvents
Y1  - 2022
U6  - https://doi.org/10.1021/acs.jpclett.1c03453
SN  - 1948-7185
VL  - 13
IS  - 10
SP  - 2459
EP  - 2466
PB  - American Chemical Society
CY  - Washington
ER  -