An empirical model for gas phase acidity and basicity estimation.

Area of Science:

• Computational Chemistry
• Physical Organic Chemistry

Background:

• Accurate estimation of gas phase acidity and basicity is crucial for understanding chemical reactivity.
• Existing models may lack applicability across diverse functional groups found in organic molecules and biomolecules.

Purpose of the Study:

• To develop robust computational models for predicting gas phase acidity and basicity.
• To cover a wide range of acidic and basic functional groups relevant to organic chemistry and biochemistry.

Main Methods:

• Linear combination models incorporating atomic descriptors like effective electronegativity, polarizability, and electrostatic potentials.
• Development of separate models for various functional groups including alcohols, carboxylic acids, and different types of amines.

Main Results:

• Models achieved a coefficient of determination (r²) above 0.8 for most functional groups, indicating high accuracy.
• Successful application demonstrated for small organic molecules, amino acid side-chains, and potentially larger systems like proteins.

Conclusions:

• The developed models provide reliable estimations of gas phase acidity and basicity.
• These models offer a versatile tool for researchers studying chemical reactivity from small molecules to complex biological systems.