TY  - JOUR
AB  - We report on the molecular structure of trimethylsilanes Si(CH3)(3)X in which the substituents X, namely (Z)-pentafluoropropen-1-yl, trifluoropropyn-1-yl, pentafluoroethyl, trifluorovinyl, vinyl, propyn-1-yl, di- and trichloromethyl, display electron withdrawing effects of varying strength. The lengths of the bonds between the silicon and the carbon atoms of X correlate with the hybridization of the respective orbitals and the steric demand of X rather than with the electron withdrawing capability. In case of chlorinated substituents dispersion effects seem to shorten the Si-C bond. Furthermore, a route for generating trifluoropropyn-1-yllithium from the cryogen 2,3,3,3-tetrafluoropropene (HFO-1234yf) and n-butyllithium is described. Tetrafluoropropen-1-yllithium is slowly formed at -80 degrees C but even at this temperature spontaneous elimination of LiF occurs. Deprotonation of the formed 3,3,3-trifluoropropyne requires temperatures of above -60 degrees C leading to trifluoropropyn-1-yllithium which appears as relatively stable at room temperature.
DA  - 2021
DO  - 10.1002/ejic.202001065
KW  - Chloroorganylsilanes
KW  - Fluoroorganylsilanes
KW  - Structure elucidation
KW  - Substituent effects
KW  - Trifluoropropynyllithium groups
KW  - Trimethylsilanes
LA  - eng
PY  - 2021
SN  - 1434-1948
TI  - Structural Characterization of Hydro-, Chloro- and Fluoroorganylsilanes with Substituents of Varying Electron Withdrawing Character
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-29506798
Y2  - 2024-11-22T14:00:27
ER  -