Sodium silox

Sodium silox
Names
	IUPAC name Sodium silox
	Systematic IUPAC name Sodium tri-tert-butylsilanolate
Identifiers
CAS Number	461703-02-6 [chemspider];
3D model (JSmol)	Interactive image;
ChemSpider	35766904;
PubChem CID	23701721;
CompTox Dashboard (EPA)	DTXSID90635729 ;
	InChI InChI=1S/C12H27OSi.Na/c1-10(2,3)14(13,11(4,5)6)12(7,8)9;/h1-9H3;/q-1;+1 Key: QAGFKHQOLBYGIF-UHFFFAOYSA-N;
	SMILES [Na+].CC(C)(C)[Si]([O-])(C(C)(C)C)C(C)(C)C;
Properties
Chemical formula	C12H27NaOSi
Molar mass	238.422 g·mol−1
Appearance	colourless solid
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Sodium silox is the name for an organosilicon compound that serves as a source of the siloxide anion [(CH₃)₃C]₃SiO⁻. Complexes of this bulky anionic ligand often adopt with low coordination numbers. Examples include Ti(silox)₃, Nb(silox)₃(PMe₃), and [Cr(silox)₃]⁻.

Properties of silox and related complexes

The sodium derivative, which has salt-like properties, is a cubane-type cluster.^[1]

Related bulky anionic ligands include C₅Me₅⁻, (Me₃Si)₂N⁻, and NacNac⁻. Silox has a larger cone angle than C₅Me₅⁻ and is a poorer donor. It is also larger than silylamides. For these reasons, silox anion forms highly unsaturated complexes.

Complexes with high coordinative unsaturation display high reactivity so long as they do not undergo intramolecular reactions. Silox offers this possibility. Examples of high reactivity exhibited by metal-silox compounds include the C-O bond in carbon monoxide and the C-N bond in pyridine.^[2]

Preparation

Na(silox) is usually prepared by deprotonation of the silanol (t-Bu)₃SiOH, which is prepared by a multistep route via the intermediacy of (t-Bu)₂SiF₂.^[3] It is also obtained by treatment of ^tBu₃SiNa with nitrous oxide.

Related compounds

Sodium trimethylsiloxide

References

^ Lerner, Hans-Wolfram; Scholz, Stefan; Bolte, Michael "The Sodium Siloxides (tBu₃SiONa)₄ and (tBu₂PhSiONa)₄: Synthesis and X-ray Crystal Structure Analysis" Organometallics 2002, 21, 3827-3830. doi:10.1021/om020318v
^ Peter T. Wolczanski "Chemistry of electrophilic metal centres coordinated by silox (^tBu₃SiO), tritox (^tBu₃CO) and related bifunctional ligands" Polyhedron, 1995, 14, 3335-3362. doi:10.1016/0277-5387(95)85014-7.
^ Edward M. Dexheimer and Leornard Spialter, Lee D. Smithson "Tri-t-butylsilane: synthesis, physical properties, derivatives, and reactivity towards ozonolysis, chlorination, fluorination, and hydrolysis" Journal of Organometallic Chemistry 102, 1975, 21-27.doi:10.1016/S0022-328X(00)90256-0.

[1] Lerner, Hans-Wolfram; Scholz, Stefan; Bolte, Michael "The Sodium Siloxides (tBu₃SiONa)₄ and (tBu₂PhSiONa)₄: Synthesis and X-ray Crystal Structure Analysis" Organometallics 2002, 21, 3827-3830. doi:10.1021/om020318v

[2] Peter T. Wolczanski "Chemistry of electrophilic metal centres coordinated by silox (^tBu₃SiO), tritox (^tBu₃CO) and related bifunctional ligands" Polyhedron, 1995, 14, 3335-3362. doi:10.1016/0277-5387(95)85014-7.

[3] Edward M. Dexheimer and Leornard Spialter, Lee D. Smithson "Tri-t-butylsilane: synthesis, physical properties, derivatives, and reactivity towards ozonolysis, chlorination, fluorination, and hydrolysis" Journal of Organometallic Chemistry 102, 1975, 21-27.doi:10.1016/S0022-328X(00)90256-0.

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