The Preparation of Hexaphenylcyclotrisilthiane and of Tetraphenylcyclodisilthiane¹

Organosilicon Derivatives of Sulfur

“…Thus, for example, the reaction of dimethyldichlorosilane with hydrogen sulfide in the presence of pyridine at room temperature leads to the formation of hexamethylcyclotrisilthiane [2,532]: Hexaphenylcyclotrisilthiane behaves analogously [481].…”

“…According to electron diffraction data [140], this angle equals 97.4 ± 0.7°. The Raman and infrared spectra of other silthianes have also been investigated [291,292,296,298,369,425,429,457,481,626,634,700,743,750,[758][759][760][849][850][851]. From spectroscopic data it follows that the symmetrical bond vibrations lis Si -S -Si in the spectra of silthianes correspond to frequencies in the range of 420-440 cm-1 with a fall to 407 cm-1 in the case of (CI2SiS~ and 395 cm-1 for (CI3SihS.…”

“…The dipole moment of hexamethyldisilthiane equals 1.85D [263]. The interatomic distances and bond angles in tetramethylcyclodisilthiane were determined by electron diffraction: Crystallographic investigations of phenylcyclosilthianes showed that crystals of hexaphenylcyc10trisilthiane are monoclinic [481]. Investigations of the NlVIR spectra of compounds of the type [(CHS)38ihX, where X = 0, S, or Se, show that with a change from X = 0 to X = 8 and Se the signals from the methyl protons are found at lower fields and not the reverse, as would have been expected from the series of electronegativities of these elements.…”

“…Like disilthiane itself [294,296], organosilthianes [12,285,298,481,515,516,664] are extremely sensitive to moisture and are hydrolyzed rapidly by water even at room temperature, with the formation of the corresponding silanols or siloxanes and hydrogen sulfide:…”

Dimeric and trimeric diorganosilicon chalcogenides (PhRSiE)2,3 (E=S, Se, Te; R=Ph, Me)

“…On heating the trimeric six-membered ring compounds (R 2 SiE) 3 (E = S, Se) interconvert to the dimeric four-membered rings (R 2 S:E) 2 [2,[6][7][8][9]. Several studies have shown [10][11][12] that this conversion proceeds via an elimination of a silathione R 2 Si@S or silaselenone R 2 Si@Se which could be trapped by several reagents.…”