Ab initio calculations have been carried out on s-trans-Nvinylmethyleneammonium, pyridinium, and related compounds to obtain rotational barriers, structures, and vibrational frequencies. The restricted Hartree-Fock (RHF) level of theory with 6-31G\*\* basis set was used for these calculations. In ad
Isotope effects in molecular mechanics (MM2). Calculations deuterium compounds
โ Scribed by Norman L. Allinger; Heather L. Flanagan
- Publisher
- John Wiley and Sons
- Year
- 1983
- Tongue
- English
- Weight
- 459 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0192-8651
No coin nor oath required. For personal study only.
โฆ Synopsis
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. They are quite good for hydrocarbons, but less so for ketones.
๐ SIMILAR VOLUMES
Simple and very efficient formulas are presented for four-body ## ลฝ . out-of-plane bend used in MM2 and MM3 force fields and improper torsion ลฝ . used in the MM4 force field internal coordinates and their first and second derivatives. The use of a small set of bend and stretch intermediates allow
Proton NMR spectra are reported for chlorotrimethylstannane, tetramethylstannane, tetramethylplumbane and dimethylmercury containing various combinations of CH, and CD, groups. Additive long-range isotope effects on chemical shifts, 4AH(D), are observed to result in increased shielding of essentiall
Deuterium-induced chemical shift differences on the 13C (DIS) are reported for a series of Schiff bases of salicylaldehydes, l-(phenyliminomethyl)naphthalen-2-ol and 4-chloro-1,7-phenanthrolin-l0-ol. Provided that corrections for the hydrogen donor atom and diamagnetic effects of the surrounding gro