Free energy drug-receptor interactions

Halogens connected to a carbon atom, such as chlorine and fluorine, withdraw electrons from other parts of the molecule and can create a large dipole moment (//) of the C-halogen bond [36] /i = C-Cl, 1.56 C-F, 1.51 C-Br, 1.48 C-I, 1.29 D), and overall reactivity and chemical inertness. The theoretical basis for using the dipole moment as a free energy related parameter in studying drug-receptor interaction and quantitative stmcture-activity relationship (QSAR) has been described for aromatic substituents of mono-substituted benzene derivatives [37]. 

Many research papers have been published on the successful use of QSAR and molecular modeling studies to understand drug-receptor interactions [60-64]. Extensive applications of QSAR in the discovery of anti-HIV drugs in academia and industry have been reported [65-67]. Many molecular modeling studies on anti-HIV inhibitors using various 3D-QSAR techniques such as, comparative molecular field analysis (CoMFA), comparative molecular similarity analysis (CoMSIA), pharmacophore generation, free-energy... 

The total free energy of interaction between a drug and its receptor provides a measure of the strength of the association between the two molecules, but tells us little or nothing... 

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