Tris(trimethylsilyl)silane

Tris(trimethylsilyl)silane
Names
	Preferred IUPAC name 1,1,1,3,3,3-Hexamethyl-2-(trimethylsilyl)trisilane
	Other names TTMS, supersilane
Identifiers
CAS Number	1873-77-4;
3D model (JSmol)	Interactive image;
ChemSpider	109749;
ECHA InfoCard	100.203.666
PubChem CID	6327365;
UNII	NN5K4PS2OA;
CompTox Dashboard (EPA)	DTXSID70940202 ;
	InChI InChI=1S/C9H27Si4/c1-11(2,3)10(12(4,5)6)13(7,8)9/h1-9H3 Key: SCHZCUMIENIQMY-UHFFFAOYSA-N;
	SMILES C[Si](C)(C)[Si]([Si](C)(C)C)[Si](C)(C)C;
Properties
Chemical formula	C9H28Si4
Molar mass	248.663 g·mol−1
Appearance	colorless liquid
Density	0.806 g/cm3
Boiling point	82–84 °C (180–183 °F; 355–357 K) 12 Torr
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Tris(trimethylsilyl)silane is the organosilicon compound with the formula (Me₃Si)₃SiH (where Me = CH₃). It is a colorless liquid that is classified as a hydrosilane since it contains an Si-H bond. The compound is notable as having a weak Si-H bond, with a bond dissociation energy estimated at 84 kcal/mol. For comparison, the Si-H bond in trimethylsilane is 94 kcal/mol. With such a weak bond, the compound is used as a reagent to deliver hydrogen atoms. The compound has been described as an environmentally benign analogue of tributyltin hydride.^[1]^[2]

Reactions

The compound can be prepared by protonation of tris(trimethylsilyl)silyl lithium, which is derived from tetrakis(trimethylsilyl)silane:^[2]

(Me₃Si)₄Si + MeLi → (Me₃Si)₃SiLi + Me₄Si

(Me₃Si)₃SiLi + HCl → (Me₃Si)₃SiH + LiCl

Alternatively, the reaction of trimethylsilyl chloride and trichlorosilane in the presence of lithium delivers the silane directly but in modest yield:^[3]

3 Me₃SiCl + HSiCl₃ + 6 Li → (Me₃Si)₃SiH + 6 LiCl

Many coordination complexes have been prepared with (Me₃Si)₃Si⁻ (hypersilyl) ligand.^[4] Chalcogenide derivatives of (Me₃Si)₃SiLi are also well developed:^[5]

3 Me₃SiLi + E → (Me₃Si)₃SiELi (E = S, Se, Te)

References

^ Chryssostomos Chatgilialoglu; Carla Ferreri; Yannick Landais; Vitaliy I. Timokhin (2018). "Thirty Years of (TMS)₃SiH: A Milestone in Radical-Based Synthetic Chemistry". Chemical Reviews. 118 (14): 6516–6572. doi:10.1021/acs.chemrev.8b00109. PMID 29938502. S2CID 49413857.
^ ^a ^b Joachim Dickhaut, Bernd Giese (1992). "Tris(trimethylsilyl)silane". Org. Synth. 70: 164. doi:10.15227/orgsyn.070.0164.
^ Bürger, H.; Kilian, W. (1969). "Spektroskopische Untersuchungen an Tris(trimethylsilyl)silan und -silan-d1". Journal of Organometallic Chemistry. 18 (2): 299–306. doi:10.1016/S0022-328X(00)85398-X.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Wilfling, Marion; Klinkhammer, Karl W. (2010). "Gold(I)-Mediated Silicon-Silicon Bond Metathesis at Room Temperature". Angewandte Chemie International Edition. 49 (18): 3219–3223. doi:10.1002/anie.200905950. PMID 20349479.
^ Arnold, John (2007). "The Chemistry of Metal Complexes with Selenolate and Tellurolate Ligands". Progress in Inorganic Chemistry. Vol. 43. pp. 353–417. doi:10.1002/9780470166444.ch4. ISBN 978-0-470-16644-4.

[1] Chryssostomos Chatgilialoglu; Carla Ferreri; Yannick Landais; Vitaliy I. Timokhin (2018). "Thirty Years of (TMS)₃SiH: A Milestone in Radical-Based Synthetic Chemistry". Chemical Reviews. 118 (14): 6516–6572. doi:10.1021/acs.chemrev.8b00109. PMID 29938502. S2CID 49413857.

[OS-2] Joachim Dickhaut, Bernd Giese (1992). "Tris(trimethylsilyl)silane". Org. Synth. 70: 164. doi:10.15227/orgsyn.070.0164.

[3] Bürger, H.; Kilian, W. (1969). "Spektroskopische Untersuchungen an Tris(trimethylsilyl)silan und -silan-d1". Journal of Organometallic Chemistry. 18 (2): 299–306. doi:10.1016/S0022-328X(00)85398-X.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[4] Wilfling, Marion; Klinkhammer, Karl W. (2010). "Gold(I)-Mediated Silicon-Silicon Bond Metathesis at Room Temperature". Angewandte Chemie International Edition. 49 (18): 3219–3223. doi:10.1002/anie.200905950. PMID 20349479.

[5] Arnold, John (2007). "The Chemistry of Metal Complexes with Selenolate and Tellurolate Ligands". Progress in Inorganic Chemistry. Vol. 43. pp. 353–417. doi:10.1002/9780470166444.ch4. ISBN 978-0-470-16644-4.

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