modeling - ORGANIC CHEMISTRY CHEM 12A Molecular Models and...

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ORGANIC CHEMISTRY LANEY COLLEGE CHEM 12A Molecular Models and Molecular Mechanics Workshop Reading: In Pavia: Essay: Molecular Modeling and Molecular Mechanics (pp. 142-149) In Wade: Section 3-7 to 3-15. Procedure 1. Make molecular models of the following alkanes: . butane, 2,3-dimethylbutane, and 3,4-dimethylheptane (be sure to use the correct hybridization in the model set for the carbon) a. For each structure find the lowest energy conformation by physically "minimizing" the interactions. b. For 2,3-dimethylbutane estimate the barriers to rotation. Generate an energy level diagram showing a complete 360 degree rotation about the internal bond (C2-C3). Show the appropriate Newman projections for each 60 degree rotation. Use the following values for the torsional and steric interactions: -H, -H eclipsing 4.2 kJ/mol -H,-CH 3 eclipsing 5.5 kJ/mol -CH 3 , -CH 3 eclipsing 11 kJ/mol -CH 3 , -CH 3 gauche 3.8 kJ/mol 2. Make a model of butane. Replace two of the hydrogen atom with chlorine atoms. How many isomers can you make?
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This note was uploaded on 01/23/2010 for the course CHEM 12A taught by Professor Corlett during the Spring '07 term at Laney College.

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