ISSN:
0192-8651
Schlagwort(e):
Computational Chemistry and Molecular Modeling
;
Biochemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Informatik
Notizen:
The proton affinity of a molecule in the gas phase is a fundamental measure of its basicity and is the factor controlling the course of many ion-molecule reactions. In this article, ab initio molecular orbital theory at the MP4/6-311 ++ G(3df, 3pd) level of theory is demonstrated to predict proton affinities (PA's) for small neutral and anionic bases to within 2 kcal mol-1. Furthermore, the errors are random, indicating that there are likely no systematic errors in either the experimental or theoretical PA's. Also, this level of theory is used to calibrate less sophisticated theoretical models which are suitable for larger molecules; the MP4/6-311 ++ G(2d, 2p) and MP2/6-311 ++ G(d, p) theoretical models should be particularly useful. A procedure for predicting the vibrational frequencies for anions is proposed and applied to CH3-, NH2-, OH-, and CN-.
Zusätzliches Material:
8 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jcc.540070309
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