Influence of substitution patterns on isomer preference in 1 : 1 chromone-methanol complexes

Area of Science:

• Computational chemistry
• Molecular spectroscopy
• Supramolecular chemistry

Background:

• Chromone-methanol clusters are valuable models for studying intermolecular interactions.
• The asymmetric ketone in chromone allows for distinct hydrogen-bonding sites, leading to 'inside' and 'outside' isomers.
• Understanding isomer preferences is crucial for predicting molecular behavior and designing new materials.

Purpose of the Study:

• To investigate how functional groups affect the balance between chromone-methanol isomers.
• To identify chromone derivatives that switch isomer preference upon electronic excitation.
• To analyze the contributions to intermolecular interaction energy using computational methods.

Main Methods:

• Density Functional Theory (DFT) simulations were used to model chromone-methanol clusters.
• Infrared spectroscopy was employed to differentiate between 'inside' and 'outside' isomers.
• Local energy decomposition analysis was applied to quantify interaction energies.

Main Results:

• Three mono-substituted and four doubly substituted chromone derivatives were identified as exhibiting isomer switching upon excitation.
• DFT simulations successfully predicted the influence of functional groups on isomer preference.
• The study provides a detailed analysis of intermolecular interaction energies in these systems.

Conclusions:

• Functional group modification offers a route to control isomer preferences in chromone derivatives.
• Electronic excitation can be used to dynamically alter intermolecular interactions.
• This research advances the understanding of non-covalent interactions and provides a platform for designing functional molecular systems.