title: Molecular Mechanics (MM4) Studies on Unusually Long Carbon-Carbon Bond Distances in Hydrocarbons.
abstract: The carbon-carbon single bond is of central importance in organic chemistry. When the molecular mechanics MM4 force field was developed beginning in the early 1990s, C-C bond lengths were not known very reliably for many important molecules, and bond lengths greater than 1.6 Å were quite poorly known experimentally. Quantum-mechanically computed values could not yet be obtained with useful accuracy in a general way. This paper examines structures now available from experiment and quantum-mechanical computations and extends the fit of the MM4 methodology to include new bond distances as long as 1.71 Å.
authors.affiliation: Center for Computational Chemistry, University of Georgia , Athens, Georgia 30602, United States.
authors.forename: Norman L
authors.initials: NL
authors.lastname: Allinger
authors.affiliation: CNC Gelcaps Corporation , No. 1205 Zhongzheng Road, Caotun Township, Nantou County 54254, Taiwan.
authors.forename: Jenn-Huei
authors.initials: JH
authors.lastname: Lii
authors.affiliation: Center for Computational Chemistry, University of Georgia , Athens, Georgia 30602, United States.
authors.forename: Henry F
authors.initials: HF
authors.lastname: Schaefer