Electron diffraction study of the molecular structure of trimethylcyclopentadienylsilane

Molecular mechanics calculations (MM3) on silanes

“…The molecular structure of trimethylsilycyclopentadiene has been studied by electron diffraction. 60 The angle between the planes C 1 C 4 C 5 and C 1 C 2 C 3 C 4 was reported to be 22 ± 4°, which is far from the MM3 calculated value, 1·2°. The authors claimed that the Si···C 2 non-bonded distance was 3·41 Å.…”

Ab Initio Study of Structures, Metallotropic 1,2-Shifts and Prototropic 1,2-Shifts of Cyclopentadienyl(trimethyl)silane, -germane and -stannane

“…1 H-NMR, 13 C-NMR, mass spectrometer and IR studies of the structures of cyclopentadienyl(trimethyl)silane, -germane andstannane indicated that the 5-Me 3 MC 5 H 5 isomer is the more stable form, in which the Me 3 M fragment is bound to a on allylic carbon atom. 15,16 In contrast to the reported sructural data for compounds 1 and 2, the electron diffraction studies of compounds H 3 SiC 5 H 5 and H 3 GeC 5 H 5 indicate a planar conformation for cyclopentadienyl rings. 4−11 The composition of this mixture has been determined by analyzing the Diels-Alder adducts.…”

“…Consequently, it can be concluded that Downloaded by [The University of British Columbia] at 10:18 20 November 2014 the reported experimental data 15,16 indicating a ring folding may be incorrect. The results calculated by HF/3-21G and B3LYP/3-21G//HF/3-21G show that the most stable isomers of compounds 1-3 are the allylic isomers (the Me 3 M fragment in an allylic position).…”

“…Veniaminov et al 15 found for 5-Me 3 SiC 5 H 5 (1) a structure by electron diffraction in the vapor phase containing a non planar C 5 H 5 ring, in which the dihedral angle between the planes C(2)-C(3)-C(4) and C(1)-C(5)-C(4) is 158 • . This ring folding also is reported for the germyl analogue.…”