4371-91-9

Basic information

• Product Name: hexamethyl diorthosilicate
• Synonyms: hexamethyl diorthosilicate;Hexamethoxypropanedisiloxane;Einecs 224-467-7;Hexamethoxy Disiloxane
• CAS NO: 4371-91-9
• Molecular Formula: C₆H₁₈O₇Si₂
• Molecular Weight: 258.3739
• EINECS: 224-467-7
• Mol File: 4371-91-9.mol
• Article Data: 7

Chemical Properties

• Boiling Point: 157°C at 760 mmHg
• Flash Point: 40.5°C
• Appearance: /
• Density: 1.06g/cm³
• Vapor Pressure: 3.63mmHg at 25°C
• Refractive Index: 1.403
• CAS DataBase Reference: hexamethyl diorthosilicate(CAS DataBase Reference)
• NIST Chemistry Reference: hexamethyl diorthosilicate(4371-91-9)
• EPA Substance Registry System: hexamethyl diorthosilicate(4371-91-9)

Safety Data

• Hazardous Substances Data: 4371-91-9(Hazardous Substances Data)

Usage

General Description

Hexamethyl diorthosilicate is a chemical compound with the formula Si2O(CH3)6. As an organosilicon compound, it is derived from silicon, oxygen, and methyl groups. It is a volatile, oily liquid that is mildly volatile and does not mix well with water. Hexamethyl diorthosilicate is typically used for silicone production, specifically in the one-step production of high-quality silicone, thanks to its ability to penetrate deep into surfaces. This also allows it to behave like a primer on diverse substrate materials for facilitating bonding and adhesion. It can be potentially dangerous if inhaled, swallowed, or if it comes into contact with skin, hence necessitates careful handling.

InChI:InChI=1/C6H18O7Si2/c1-7-14(8-2,9-3)13-15(10-4,11-5)12-6/h1-6H3

Upstream product

• 1634-04-4 tert-butyl methyl ether 
• 4668-00-2 chlorotrimethoxysilane 
• 18816-60-9 tetrakis(diphenylmethoxy)silane 
• 18230-57-4 hydroxytrimethoxysilane 
• 10026-04-7 tetrachlorosilane 
• 67-56-1 methanol 
• 133902-86-0 Chlor-pentakis(dimethylamino)-disiloxan 
• 681-84-5 tetramethylorthosilicate 
• 112926-00-8 silica gel 

Relevant articles and documents

Reaction of silicon with alcohols in autoclave

A reaction of activated silicon with alcohols in an autoclave at 240—270 °C was studied. It was found that primary alcohols form tetraalkoxysilanes Si(OR)4 with high selectivity (up to 97%), while the secondary PriOH gave a mixture of compounds HSi(OPri)3, Si(OPri)4, HSi(OPri)2OSi(OPri)2H, HSi(OPri)2OSi(OPri)3, and Si(OPri)3OSi(OPri)3 with the predominance of trialkoxysilane (up to 67%). Carrying out the reaction under the indicated conditions has the advantage of experimental simplicity, reagent availability, high conversion of silicon, good isolated yields of products.

Practical conversion of chlorosilanes into alkoxysilanes without generating HCl

Alcohol-free: A versatile, efficient, and practical synthesis of alkoxysilanes without generation of HCl involves the reaction of chlorosilanes with unsymmetrical ethers in the presence of a Lewis acid (see scheme). The reaction proceeds through selective cleavage of C-O bonds and is superior to conventional processes. Industrially feasible reagents are used and only one by-product results. Copyright