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Conformational energies and rotational barriers in 3-methyl-1-butene and 1-butene: An ab initio and molecular mechanics study

✍ Scribed by Ingrid Pettersson; Klaus Gundertofte

Publisher
John Wiley and Sons
Year
1991
Tongue
English
Weight
421 KB
Volume
12
Category
Article
ISSN
0192-8651

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✦ Synopsis

Abstract

The calculated result obtained with MM2(87) for the rotation of the isopropyl group in 3‐methyl‐1‐butene is not in agreement with experimental data. In order to reparametrize the C~sp~2‐C~sp~3‐C~sp~‐C~sp~3 torsional angle, 3‐methyl‐1‐butene and 1‐butene have been studied by molecular mechanics (MM2(87)) and ab initio (MP2/6‐31G* and MP3/6‐31G*) calculations. The reparametrization of the torsional angle gives calculated results from MM2(87) in agreement with experimental data and ab initio calculations for both 3‐methyl‐1‐butene and 1‐butene. The calculated barriers for the rotation of alkyl groups in alkylbenzenes are improved with these new parameters.

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