Using a Convenient, Quantitative Model for Torsional Entropy to Establish Qualitative Trends for Molecular Processes That Restrict Conformational Freedom

Journal of Organic Chemistry

Volumn 63, Issue 10, 1998, Pages 3168-3175

  Mammen, Mathai ^a   Shakhnovich, Eugene I ^a   Whitesides, George M ^a  

^a HARVARD UNIVERSITY   (United States)

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EID: 0000598486     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo970943n     Document Type: Article

References (64)

1. o is the maximum internal energy (J/mol, referenced to U = 0 at the torsional global minimum), and φ is the torsional angle (rad) (Guggenheim). The validity of this shape has been questioned (see: Blade, E., Kimball, G. E. J. Chem. Phys. 1950, 18, 630). In our work, we make no assumption about the shape of the well (see Appendix 1). Nevertheless, the wide range in the rates of rotation about a single bond serve as a qualitative illustration that the entropies of torsional motion may not be all the same.
2. o is the maximum internal energy (J/mol, referenced to U = 0 at the torsional global minimum), and φ is the torsional angle (rad) (Guggenheim). The validity of this shape has been questioned (see: Blade, E., Kimball, G. E. J. Chem. Phys. 1950, 18, 630). In our work, we make no assumption about the shape of the well (see Appendix 1). Nevertheless, the wide range in the rates of rotation about a single bond serve as a qualitative illustration that the entropies of torsional motion may not be all the same.
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