Vibrational spectra and ab initio analysis of tert-butyl, trimethylsilyl, and trimethylgermyl derivatives of 3,3-dimethylcyclopropene. I. 3,3-Dimethyl-1,2-bis(tert-butyl)cyclopropene.
The geometrical parameters of 3,3-dimethyl-1,2-bis(tert-butyl)cyclopropene were optimised completely at the HF/6-31G* level. The HF/6-31G*//HF/6-31G* force field was calculated and scaled using Pulay's scaling procedure. The set of 17 scale factors (for a 105-dimensional problem) was compiled from the sets obtained previously for 3,3-dimethyl-1-butene and 1-methyl-, 1,2-dimethyl-, and 3,3-dimethylcyclopropene. The vibrational problem was solved using the scaled quantum mechanical force field (QMFF) and assignments of the vibrational frequencies of 3,3-dimethyl-1,2-bis(tert-butyl)cyclopropene were considered in comparison with the known assignments of 3,3-dimethyl-1-butene and 3,3-dimethylcyclopropene. Assignments of four experimental IR bands of 3,3-dimethyl-1,2-bis(tert-butyl)cyclopropene given in the literature are suggested.
Panchenko
Yu N
YN
Laboratory of Molecular Spectroscopy, Division of Physical Chemistry, Department of Chemistry, M. V. Lomonosov Moscow State University, Moscow 119899, Russia. panchenk@physch.chem.msu.su
De Maré
G R
GR
D003521:Cyclopropanes / Q000032:analysis* / Q000737:chemistry*; D008958:Models, Molecular; D008962:Models, Theoretical; D013053:Spectrophotometry / Q000379:methods*
C475675:3,3-dimethyl-1,2-bis(tert-butyl)cyclopropene; D003521:Cyclopropanes; C021985:cyclopropene