Beyond the Molecule: Intermolecular Forces from Gas Liquefaction to X-H⋅⋅⋅π Hydrogen Bonds

Area of Science:

• Physical Chemistry
• Molecular Physics
• Biophysics

Background:

• Early 19th-century studies on gas liquefaction sparked interest in molecule-molecule interactions.
• Andrews' 1869 experiments and van der Waals' 1873 equation advanced understanding of real gas behavior.
• Keesom, Debye, and London elucidated electrostatic and quantum mechanical origins of intermolecular forces in the early 20th century.

Purpose of the Study:

• To provide a historical perspective on the scientific progress in understanding intermolecular interactions.
• To revisit key experimental and theoretical milestones in the field.
• To highlight the significance of these interactions in biological systems.

Main Methods:

• Historical review of scientific literature and classical experiments.
• Analysis of theoretical formulations from the 19th and 20th centuries.
• Tracing the development of concepts like critical phenomena and hydrogen bonding.

Main Results:

• Demonstrated the gradual development of intermolecular force theories over two centuries.
• Highlighted the foundational contributions of Andrews, van der Waals, Keesom, Debye, London, and Lewis.
• Established the crucial role of hydrogen bonding in the aggregation of biological macromolecules.

Conclusions:

• Intermolecular interaction science has a rich history rooted in physical chemistry and gas studies.
• Understanding these forces is fundamental to comprehending the structure and function of biological systems.
• The field continues to evolve, building upon classical experiments and theoretical frameworks.