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Lec 35 - Understanding Molecular Structure and Energy through Standard Bonds

"Lec 35 - Understanding Molecular Structure and Energy through Standard Bonds" Freshman Organic Chemistry (CHEM 125) Although molecular mechanics is imperfect, it is useful for discussing molecular structure and energy in terms of standard covalent bonds. Analysis of the Cambridge Structural Database shows that predicting bond distances to within 1% required detailed categorization of bond types. Early attempts to predict heats of combustion in terms of composition proved adequate for physiology, but not for chemistry. Group- or bond-additivity schemes are useful for understanding heats of formation, especially when corrected for strain. Heat of atomization is the natural target for bond energy schemes, but experimental measurement requires spectroscopic determination of the heat of atomization of elements in their standard states. 00:00 - Chapter 1. The Limits of Molecular Mechanics Programs 07:32 - Chapter 2. The Cambridge Structural Database and the Demands of Predicting Bond Characteristics 21:36 - Chapter 3. Calculating Chemically Useful Heats of Formation 42:17 - Chapter 4. Measuring Heats of Atomization with Bond Energies Complete course materials are available at the Open Yale Courses website: http://open.yale.edu/courses This course was recorded in Fall 2008.

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Lecture list for this course

Lec 1 - How Do You Know?

Lec 2 - Force Laws, Lewis Structures and Resonance

Lec 3 - Double Minima, Earnshaw's Theorem and Plum-Puddings

Lec 4 - Coping with Smallness and Scanning Probe Microscopy

Lec 5 - X-Ray Diffraction

Lec 6 - Seeing Bonds by Electron Difference Density

Lec 7 - Quantum Mechanical Kinetic Energy

Lec 8 - One-Dimensional Wave Functions

Lec 9 - Chladni Figures and One-Electron Atoms

Lec 10 - Reality and the Orbital Approximation

Lec 11 - Orbital Correction and Plum-Pudding Molecules

Lec 12 - Overlap and Atom-Pair Bonds

Lec 13 - Overlap and Energy-Match

Lec 14 - Checking Hybridization Theory with XH_3

Lec 15 - Chemical Reactivity: SOMO, HOMO, and LUMO

Lec 16 - Recognizing Functional Groups

Lec 17 - Reaction Analogies and Carbonyl Reactivity

Lec 18 - Amide, Carboxylic Acid and Alkyl Lithium

Lec 19 - Oxygen and the Chemical Revolution (Beginning to 1789)

Lec 20 - Rise of the Atomic Theory (1790-1805)

Lec 21 - Berzelius to Liebig and Wöhler (1805-1832)

Lec 22 - Radical and Type Theories (1832-1850)

Lec 23 - Valence Theory and Constitutional Structure (1858)

Lec 24 - Determining Chemical Structure by Isomer Counting (1869)

Lec 25 - Models in 3D Space (1869-1877); Optical Isomers

Lec 26 - Van't Hoff's Tetrahedral Carbon and Chirality

Lec 27 - Communicating Molecular Structure in Diagrams and Words

Lec 28 - Stereochemical Nomenclature; Racemization and Resolution

Lec 29 - Preparing Single Enantiomers and the Mechanism of Optical Rotation

Lec 30 - Esomeprazole as an Example of Drug Testing and Usage

Lec 31 - Preparing Single Enantiomers and Conformational Energy

Lec 32 - Stereotopicity and Baeyer Strain Theory

Lec 33 - Conformational Energy and Molecular Mechanics

Lec 34 - Sharpless Oxidation Catalysts and the Conformation of Cycloalkanes

Lec 36 - Bond Energies, the Boltzmann Factor and Entropy

Lec Last - Potential Energy Surfaces, Transition State Theory and Reaction Mechanism