Sodium silox is the name for an
organosilicon compound that serves as a source of the siloxide anion
CH3)3Csub>3SiO
−. Complexes of this bulky anionic
ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...
often adopt with low coordination numbers. Examples include Ti(silox)
3, Nb(silox)
3(PMe
3), and
r(silox)3sup>−.
Properties of silox and related complexes
The sodium derivative, which has salt-like properties, is a
cubane-type cluster
A cubane-type cluster is an arrangement of atoms in a molecular structure that forms a cube. In the idealized case, the eight vertices are symmetry equivalent and the species has Oh symmetry. Such a structure is illustrated by the hydrocarbon cub ...
.
Related bulky anionic ligands include
C5Me5−, (Me
3Si)
2N
−, and
NacNac−. Silox has a larger
cone angle than C
5Me
5− 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
In chemistry, a saturated compound is a chemical compound (or ion) that resists the addition reactions, such as hydrogenation, oxidative addition, and binding of a Lewis base. The term is used in many contexts and for many classes of chemical c ...
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.
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)
2SiF
2.
[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..] It is also obtained by treatment of
tBu
3SiNa with
nitrous oxide
Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has a ...
.
Related compounds
*
Sodium trimethylsiloxide
Sodium trimethylsiloxide is an organosilicon compound with the formula NaOSi(CH3)3. It is the sodium salt of the conjugate base derived from trimethylsilanol. A white solid, its molecular structure consists of a cluster with Na-O-Na linkages on t ...
References
{{Reflist
Organosilicon compounds
Sodium compounds