Speaker
Description
The cluster formed by chromone and methanol serves as an excellent model for studying the various contributions to intermolecular interaction energy. The asymmetric ketone motif of chromone provides distinct hydrogen-bonding sites, enabling the differentiation between an "inside" and an "outside" isomer.
We present the delicate balance between these two competing arrangements, investigated by combining IR/R2PI and UV/IR/UV spectroscopy in a molecular beam, supported by quantum-chemical calculations. Upon electronic excitation, chromone undergoes efficient intersystem crossing into the triplet manifold, allowing studies on aromatic molecule–solvent complexes to be extended to a cluster in a triplet state. We show that in both electronic states, the “outside” isomer dominates experimentally, in agreement with simulations performed at the DFT, SAPT0, and DLPNO-CCSD(T) levels.
These findings raise the question of whether chromone derivatives could exhibit a change in binding site preference upon electronic excitation. To explore this, we screen a variety of chromone derivatives with functional groups at positions 2 and 6 of the chromone backbone. A detailed study using DFT simulations identifies three chromone derivatives that meet this criterion.
| Keywords | Hydrogen bond: medium, State of the system: gas |
|---|---|
| This abstract is submitted for.... | HBond 2025 conference |
