Sodium silox

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]⁻.

Sodium silox

Stereo structural formula of tetrameric sodium silox
Names
IUPAC name Sodium silox
Systematic IUPAC name Sodium tri-tert-butylsilanolate
Identifiers
CAS Number	461703-02-6 Y[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

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