High-pressure freezing, crystal structure studies and SiCF3 bond polarizability of trimethyl(trifluoromethyl)silane

Improved synthesis, structure, and reactivity of 1,4-bis(trimethylsilyl)octafluorobutane

“…Compound 1 crystallizes in the P2 1 2 1 2 1 space group, with two molecules in the asymmetric unit. The Si-C CF3 bond lengths of all the molecules in the unit cell average to 1.942 (19) Å , which is similar to the Si-C CF3 bond length of 1.943(12) that was determined experimentally for trimethyl(-trifluoromethyl)silane by Olejniczak and co-workers [25]. Woski and co-workers determined a much shorter Si-C CF3 bond length of 1.917(5) Å for trimethyl(trifluoromethyl)silane, but this value was much different than those derived from gas phase calculations (1.948 Å for Hartree Fock and 1.937 Å for MP2) and microwave spectroscopy/gas electron diffraction techniques (1.941(3) Å ) [26].…”

“…Because of the lack of crystallinity of many perfluoroalkyl silanes, reports of crystal structures are rare [23][24][25][26][27][28]. The structure of trimethyl(trifluoromethyl)silane, for instance, could only be obtained through high pressure freezing in a diamond anvil cell [25] or by use of an optical heating and crystallization device [26].…”

“…The structure of trimethyl(trifluoromethyl)silane, for instance, could only be obtained through high pressure freezing in a diamond anvil cell [25] or by use of an optical heating and crystallization device [26]. Compound 1, however, is a higher melting solid (melting point of 28-29 8C), [20] and crystals grown from slowly cooling a melt of 1 could be quickly mounted on a diffractometer equipped with a standard low temperature cooling device.…”

Structural Characterization of Hydro‐, Chloro‐ and Fluoroorganylsilanes with Substituents of Varying Electron Withdrawing Character

“…C4, Si1, C1 and F1 are located on the mirror plane. Contrary to trifluoromethylsilane 2 e , where the fluorine atoms and the methyl groups are in a staggered configuration, [24] in 2 b the eclipsed conformation is favored.…”

“…C3, Si1, C1, C2 and F3 are located on a mirror plane. Similar to trifluoromethylsilane 2 e [24] the pentafluoroethyl group is present in a staggered configuration relative to the methyl groups.…”