New and groundbreaking applications of conceptual quantum chemistry
This groundbreaking book is about chemical bonds, their intrinsic energies, and the corresponding dissociation energies relevant to reactivity problems. It is the first book dedicated to conceptual quantum chemistry that helps researchers understand chemical principles and predict chemical properties based on the relationship between intrinsic and dissociation energies. It therefore offers new insights into how the environment of a molecule can modify its destiny.
The book is divided into three sections:
Section One, Charge Distributions, defines the quantum mechanical variables used in a formula that features the electronic charges carried by bond–forming atoms. The author describes the partitioning of ground–state atoms into core and valence regions in real space as well as a similar core–valence partitioning in molecules. Next, atomic charges are discussed, followed by their correlation with NMR shifts. Lastly, the author offers a brief investigation of the ionization of alkanes and population analyses.
Section Two, Chemical Bonds. Energy Calculations, presents thermochemical formulas and the description of saturated systems. Next, the author examines the derivation for unsaturated systems and discusses the energy of dissociation.
Section Three, Applications, compares calculated and experimental enthalpy results for a body of 224 molecules. Examples of applications to deoxyadenosine and deoxyguanosine help readers understand the depurination of DNA structures that occurs with cancer.
All formula derivations were developed in the author′s laboratories and are presented in their entirety. Atomic Charges, Bond Properties, and Molecular Energies opens new avenues of investigation for researchers and students who use quantum chemical techniques, including organic chemists, biochemists, molecular biologists, materials scientists, and nanoscientists.
I. CHARGE DISTRIBUTIONS.
1.1 The Bond Energy Model.
2. Theoretical Background.
2.1 The Hartree –Fock Approximation.
2.2 Hartree –Fock –Roothaan Orbitals.
2.3 Configuration Interaction Calculations.
3. Core and Valence Electrons.
3.2 Atomic Core and Valence Regions.
3.3 The Valence Region Energy of Atoms.
4. The Valence Region of Molecules.
4.2 The Core –Valence Separation in Real Space.
4.3 Formula for the Valence –Region Energy.
4.4 Interface with the Orbital Model.
4.5 Approximation for the Valence Energy.
4.6 Perturbation of the Valence Region.
5. Inductive Effects; Atomic Charges.
5.2 The Inductive Effects.
5.3 Meaningful Atomic Charges.
5.4 Selected Reference Net Atomic Charges.
6. Atomic Charges and NMR Shifts.
6.3 Merits of Charge –Shift Relationships.
6.4 Aromatic Hydrocarbons.
6.5 Relationships Involving sp3 Carbon Atoms.
6.6 Relationships Involving Olefinic Carbons.
6.7 Carbon Bonded to Nitrogen or Oxygen.
6.8 Correlations Involving N–15 NMR Shifts.
6.9 Correlations Involving O–17 Atoms.
7. Charges and Ionization Potentials.
8. Population Analysis.
8.1 The Standard Mulliken Formula.
8.2 Modified Population Analysis.
8.3 An Adequate Approximation.
II. CHEMICAL BONDS. ENERGY CALCULATIONS.
9. Thermochemical Formulas.
9.1 Basic Formulas.
9.2 Zero –Point and Heat –Content Energies.
9.3 Concluding Remarks.
10. The Chemical Bond: Theory (I).
10.2 Nonbonded Interactions.
10.3 Reference Bonds.
10.4 Bond Energy: Working Formulas.
10.5 Basic Theoretical Parameters.
10.6 Saturated Molecules.
11. The Chemical Bond: Theory (II).
11.1 Valence Atomic Orbital Centroids.
11.2 Unsaturated Systems.
12. Bond Dissociation Energies.
12.3 Nonbonded Interactions.
12.4 Selected Reorganizational Energies.
13. Saturated Hydrocarbons.
13.1 Acyclic Alkanes.
14. Unsaturated Hydrocarbons.
14.2 Aromatic Molecules.
15. Nitrogen –Containing Molecules.
15.1 Amines: Charges of the Carbon Atoms.
15.2 Nitrogen Charges and Bond Energies.
16. Oxygen Containing Molecules.
16.3 Carbonyl Compounds.