## Abstract Alternative methods of estimating atomic charges in haloalkanes are presented, derived from quantum mechanical and classical treatments. A scheme based on a breakdown of the transmission of charge by polar atoms into oneβbond, twoβbond, and threeβbond additive contributions is given, in
Approaches to charge calculations in molecular mechanics. 2 Resonance effects in conjugated systems
β Scribed by Raymond J. Abraham; Brian Hudson
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- English
- Weight
- 859 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0192-8651
No coin nor oath required. For personal study only.
β¦ Synopsis
A previously published scheme of estimating atomic charges in haloalkanes is extended to include olefines, alcohols amines, acids, ethers, and amides. In the conjugated systems the effects of mesomeric transfer of charge are explicitly included. Generally good agreement with the observed dipole moments of these compounds and their substituted derivatives is found. The atomic charges so obtained are compared with those of other semiempirical and quantum-mechanical calculations for the amide group. The charges so obtained fall within the range of values obtained by these other schemes, supporting the general validity of this approach.
π SIMILAR VOLUMES
## Abstract Parameters have been derived so as to enable the inclusion of deuterium in the MM2 molecular mechanics force field. Several compounds were studied and the results are compared with experiment. The results are never qualitatively wrong, but the accuracy ranges from excellent to only fair
The molecular mechanics (MMPB) description of the torsion of a methyl group attached to a conjugated system has been improved by using bond order dependent torsional force constants.