Structural Insights into N,N-Diethyl-2-hydroxyacetamide Using Matrix Isolation Infrared Spectroscopy and DFT...

Area of Science:

• Computational Chemistry
• Spectroscopy
• Molecular Interactions

Background:

• Understanding molecular conformation is crucial for predicting chemical behavior.
• N,N-dialkyl-2-hydroxyacetamides are relevant in various chemical contexts.
• Previous studies have not fully elucidated the conformational landscape of DEHyA.

Purpose of the Study:

• To determine the conformational space of N,N-diethyl-2-hydroxyacetamide (DEHyA).
• To identify the key interactions stabilizing its low-energy conformers.
• To compare DEHyA's conformational behavior with its higher homologue, DOHyA.

Main Methods:

• Integrated experimental-computational approach.
• Matrix isolation infrared spectroscopy at cryogenic temperatures.
• Density functional theory (DFT) calculations, including NCI, ESP, IBSI, and NBO analyses.

Main Results:

• Identified 15 distinct conformers of DEHyA, with CC(g±g±) as the global minimum.
• Confirmed stabilization by intramolecular hydrogen bonding, supported by hyperconjugative and tetrel interactions.
• Demonstrated charge-transfer electron delocalization as a key factor in conformational preference.

Conclusions:

• Intramolecular hydrogen bonding is the primary stabilizing force for DEHyA conformers.
• Secondary hyperconjugative and tetrel effects contribute to conformational stability.
• Conformational preference is governed by cooperative noncovalent interactions and charge-transfer delocalization.