Table of Contentes.- I. Basis of the Quantum Theory of the Chemical Reactivity Of Molecules.- 1. Introduction.- A. General Points Regarding Chemical Reactivity.- B. The Part Played by the Walls.- C. The Part Played by Impurities.- D. Part Played by Inert Gases and Solvents.- E. Analytical Balance and Mechanism of Reaction.- F. Levels of Vibration, Rotation and Conformations.- G. The Role of Quantum Chemistry.- 2. Equilibrium Constants in the Gaseous Phase.- A. Basic Formula.- B. Example of Para and Ortho Hydrogen.- C. Expression of the Macroscopic Thermodynamic Magnitudes as a Function of the Statistical Thermodynamic Magnitudes.- D. Regarding the Relationships of the Equilibrium Constants.- 3. Rate Constants of a Bimolecular Process in the Gaseous Phase.- A. The Hypothesis of a Transition State.- B. Expression of the Rate Constant of Decomposition of the Intermediate Complex.- C. Reaction Between a Hydrogen Atom and a Hydrogen Molecule.- D. Combination of Two Hydrogen Atoms.- 4. Rate Constants of the Monomolecular and Termolecular Processes in the Gaseous Phase.- A. The Combination of Oxygen and Nitrogen Peroxide.- B. A Few Remarks Regarding the Behaviour of the Unimolecular Processes.- References.- II. Intermolecular Forces, Interaction Between Non-Bonded Atoms, Conformational Equilibria.- 1. Introduction.- 2. Brief Analysis of the Methods of Calculation of Intermolecular Interactions.- A. Classification of Intermolecular Forces.- B. Electrostatic Forces.- C. Polarisation Forces.- D. Dispersion Forces.- E. Exclusion Forces.- F. On Forces by Charge Transfer.- G. The Hydrogen Bond.- H. Statistical Means and the Relative Importance of Molecular Interactions.- I. Empirical Treatment of Intermolecular Interactions.- 3. Interaction Between Unbonded Atoms.- A. Van der Waal’s Radii.- B. Conformations of acyclic Paraffins, Potential Barriers to Internal Rotation.- C. Conformational Equilibria in the Cyclane Series, Baeyer’s Tension, Cotton’s Effect.- D. Total Energy of Conjugated Molecules, Steric Effects, Spatial Conjugation.- References.- III. Equilibrium Constants of Reversible Reactions in Solution.- 1. Introduction.- 2. The Equilibrium Between the Triplet State and the Singlet State of Biradicaloid Molecules.- 3. Return to the Solvent Effect.- 4. Polarographic Semi-Wave Potential of Conjugated Molecules.- A. The Case of Hydrocarbons.- B. The Case of Other Conjugated Molecules.- 5. Other Oxidation-Reduction Equilibria.- A. Reduction Potential of Conjugated Hydrocarbons.- B. Oxidation Potential of Phenols.- C. Oxidation-Reduction Potential of Quinones.- D. Biochemical Applications.- 6. Strength of Acids and Bases.- A. Introduction.- B. Strength of Amino-Acids.- C. The Acid-Basic Character of Conjugated Hydrocarbons in the Ground State and in Their First Excited States.- D. Strength of Hetero-Atomic Conjugated Molecules in the Fundamental State.- E. The Effect of Electronic Excitation on the Acid/Basic Properties of Hetero-Atomic Conjugated Molecules.- 7. The Association Constants.- A. Association Between an Acceptor and a Proton Donor.- B. Other Examples.- 8. Tautomeric Equilibria: Application to the Study of the Mechanism of Mutations.- References.- IV. Rate Constants of a Few Reactions of Organic Chemistry.- 1. Introduction.- 2. A Few Examples of Studies of Rate Constants in the Field of Saturated Hydrocarbons and Their Derivatives.- A. Nucleophilic Substitutions SN2.- B. Nucleophilic Substitutions SN1.- C. Radical Reactions.- D. Chemistry of Radiations.- 3. A Few Examples of Studies of Rate Constants in the Field of Unsaturated Organic Molecules.- A. Substitution on an Alternating Conjugated Hydrocarbon, Localisation Energy and Method of Molecular Diagrams.- B. Other Examples of Substitutions on an Atom Belonging to the Delocalised System of a Conjugated Molecule.- C. Other Types of Substitution.- D. The Diene Synthesis and Addition Reactions.- E. Other Reactions.- F. Polymerisation Reactions.- 4. The Reactivity of Organic Molecules in an Excited Electronic State.- A. Introduction.- B. Electrophilic Substitutions.- C. Return to the Case of Butadiene.- D. Miscellaneous Studies.- References.- Index Of Names.- Index Of Subjects.