Furan-formic acid dimers: an ab initio and matrix isolation study

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Spectroscopy

Background:

• Understanding molecular interactions is crucial in chemistry.
• Formic acid and furan are fundamental organic molecules with potential for complex formation.

Purpose of the Study:

• To investigate the structures and binding energies of formic acid-furan dimers.
• To classify the types of interactions governing these complexes.
• To experimentally validate computational findings.

Main Methods:

• Ab initio calculations (MP2/6-311++G(d,p)) were employed to model dimer geometries and energies.
• Basis set superposition error (BSSE) corrections were applied.
• Matrix isolation spectroscopy was used to record experimental infrared (IR) spectra.

Main Results:

• Nine stable formic acid-furan complexes were identified with binding energies ranging from -3.91 to -0.82 kcal/mol.
• Interactions include OH...O, C=O...H, HO...H, CH...O, OH...pi, and CH...pi.
• Two main types of dimers were classified based on hydrogen bonding interactions.
• Experimental IR spectra confirmed the most stable dimer as the major product.

Conclusions:

• The study elucidates the nature of non-covalent interactions in formic acid-furan systems.
• Computational and experimental results are in good agreement, validating the identified structures.
• The findings provide insights into the aggregation behavior of these molecules.