1438-82-0

Basic information

• Product Name: PENTAMETHYLDISILOXANE
• Synonyms: pentamethyl-disiloxan;PENTAMETHYLDISILOXANE;PENTAMETHYLDISILOXANE 97+%;(Trimethylsiloxy)dimethylsilane;1,1,1,3,3-Pentamethylpropanedisiloxane;2,2,4-Trimethyl-3-oxa-2,4-disilapentane;Trimethylsiloxydimethylsilane;Dimethyl(trimethylsilyloxy)silane
• CAS NO: 1438-82-0
• Molecular Formula: C₅H₁₆OSi₂
• Molecular Weight: 148.35
• EINECS: 215-873-5
• Product Categories: Chemical Synthesis;Organometallic Reagents;Organosilicon;Siloxanes
• Mol File: 1438-82-0.mol

Chemical Properties

• Boiling Point: 86 °C(lit.)
• Flash Point: -9°C
• Appearance: /
• Density: 0.760 g/mL at 20 °C(lit.)
• Refractive Index: n20/D 1.373
• Water Solubility: Not miscible or difficult to mix in water.
• Sensitive: Moisture Sensitive
• BRN: 1734568
• CAS DataBase Reference: PENTAMETHYLDISILOXANE(CAS DataBase Reference)
• NIST Chemistry Reference: PENTAMETHYLDISILOXANE(1438-82-0)
• EPA Substance Registry System: PENTAMETHYLDISILOXANE(1438-82-0)

Safety Data

• Hazard Codes: F
• Statements: 11
• Safety Statements: 16-23-24/25
• RIDADR: UN 1993 3/PG 2
• WGK Germany: 3
• F: 10-21
• TSCA: Yes
• HazardClass: 3
• PackingGroup: II
• Hazardous Substances Data: 1438-82-0(Hazardous Substances Data)

Usage

Uses

Different sources of media describe the Uses of 1438-82-0 differently. You can refer to the following data:
1. Pentamethyldisiloxane, is an organosilicon compound used in synthesis of siloxane-polyether copolymer surfactants. Pentamethyldisiloxane can also be used as source of the trimethylsilyl functional group in organic synthesis.
2. Pentamethyldisiloxane is used in the synthesis of siloxane-polyether copolymer surfactants. It is also used as source of trimethylsilyl functional group in organic synthesis.

Synthesis

Take prepared potassium trimethylsilanolate 1.12kg in 2L of anhydrous tetrahydrofuran, was added dropwise with stirring dimethylchlorosilane1kg, dropwise, room temperature reaction 1h, filtered, concentrated, extracted with ether, dried and concentrated to give a high purity of 98% or more of pentamethyl disiloxane 1.2kg.

InChI:InChI=1/C5H15OSi2/c1-7(2)6-8(3,4)5/h1-5H3

Upstream product

• 75-54-7 Dichloromethylsilane 
• 75-77-4 chloro-trimethyl-silane 
• 1066-35-9 dimethylmonochlorosilane 
• 676-58-4 methylmagnesium chloride 
• 1066-40-6 Trimethylsilanol 
• 15933-59-2 1,1,3,3-tetramethyldisilazane 
• 3277-26-7 1,1,3,3-Tetramethyldisiloxane 
• 107-46-0 Hexamethyldisiloxane 
• 2943-62-6 1-chloro-1,1,3,3,3-pentamethyldisiloxane 
• 18156-38-2 methoxypentamethyldisiloxane 
• 18182-35-9 dimethyl(tert-butyl)aminosilane 
• 2441-21-6 iododimethylsilane 
• 1825-62-3 ethyl trimethylsilyl ether 
• 812-15-7 1,1,1,2,2-pentamethyldisilane 

Downstream Products

• 18044-44-5 1,1,1,3,3-pentamethyl-3-(3-(oxiran-2-ylmethoxy)propyl)disiloxane 
• 31024-71-2 N-(3-Pentamethyldisiloxanylpropyl)anilin 
• 3439-25-6 (2-Methyldichlorsilyl-ethyl)-pentamethyldisiloxan 
• 6231-68-1 1,2-bis(1,1-3,3,3-pentamethyldisiloxanyl)ethane 
• 58110-16-0 2-Methyl-2-[2-(1,1,3,3,3-pentamethyl-disiloxanyl)-ethyl]-4,4,6,6-tetraphenyl-[1,3,5,2,4,6]trioxatrisilinane 
• 55363-73-0 2,4,6,8-Tetramethyl-2,4-bis-[2-(1,1,3,3,3-pentamethyl-disiloxanyl)-ethyl]-6,8-diphenyl-[1,3,5,7,2,4,6,8]tetroxatetrasilocane 
• 2943-62-6 1-chloro-1,1,3,3,3-pentamethyldisiloxane 
• 23029-21-2 γ-(aminopropyl)pentamethyldisiloxane 
• 14579-47-6 1-cyclohexyl-1,1,3,3,3-pentamethyldisiloxane 
• 18151-85-4 <1-(2-methylpropenoyloxy)propyl>pentamethyldisiloxane 
• 834-14-0 p-benzylanizole 
• 33335-65-8 C₅H₁₅OSi₂⁽¹⁺⁾ 
• 3277-26-7 1,1,3,3-Tetramethyldisiloxane 
• 107-46-0 Hexamethyldisiloxane 

Relevant articles and documents

A disiloxane equilibration approach to the preparation and characterization of 5,5'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bisbicycloheptane-2,3-dicarboxylic anhydride

The preparation of 5,5'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bisbicycloheptene-2,3-dicarboxylic anhydride, 3, by a novel synthetic approach was found to be an effective method to isolate this disiloxane which is difficult to purify.The structure of the diastereomerically mixed product was confirmed by a combination of nuclear magnetic resonance spectroscopic and liquid chromatographic studies and correlated to the X-ray structure from the D,L-isomer.The hydrosilation of bicyclohept-5-ene-2,3-dicarboxylic anhydride 1 by 1,1,3,3-tetramethyldisiloxane and pentamethyldisiloxane is compared.

Kinetic Investigation of the Platinum-catalysed Hydrosilylation of Vinylsiloxanes with Hydrogensiloxanes

A kinetic investigation of the platinum-catalysed hydrosilylation of monofunctional oligomeric vinylsiloxanes by monofunctional oligomeric hydrogensiloxanes was performed under stoichiometric conditions with use of quantitative 1H-NMR spectrometry.The reaction rate up to 50percent conversion can be expressed by v=k .During further hydrosilylation the kinetic changed to second order.No induction period was observed.A hydrogensiloxane with a dimethylsilyl end group gives much higher rates than a siloxane with a methylsiloxy group.The main reactions of all hydrosilylations, determined by GC-MS and 29Si-NMR, are β-additions.Less then 5percent α-products are obtained.

Preparation method and application of trimethyl silicon alkoxide

The invention discloses a preparation method and an application of trimethyl silicon alkoxide. The preparation method includes the preparation steps: placing hexamethyldisiloxane and potassium hydroxide into a 10L three-mouth flask; adding 10ml of alcohol preparations; performing heating reflux for 48 hours; dividing water by a water knockout trap; cooling, filtering and drying materials to obtain white solid potassium trimethylsilanolate. Inexpensive trimethyl silicon alkoxide (MM) in industrial production serves as a raw material, and the trimethyl silicon alkoxide and the potassium hydroxide are subjected to heating reflux reaction under various catalysts to prepare potassium trimethylsilanolate with high content. All the catalysts are beneficial to dissolution of the potassium hydroxide, and reaction is facilitated.

1,1,1,3,3,5,5-heptamethyltrisiloxane preparation method

The present invention discloses a 1,1,1,3,3,5,5-heptamethyltrisiloxane preparation method, wherein 1,1,1,3,3,3-hexamethyldisiloxane and 1,1,3,3-tetramethyldisiloxane are subjected to co-hydrolysis for 1-4 h under catalysis of concentrated sulfuric acid to obtain 1,1,1,3,3-pentamethyldisiloxane, the 1,1,1,3,3-pentamethyldisiloxane and dimethyl dimethoxy silicane are subjected to co-hydrolysis for 1-3 h under catalysis of concentrated sulfuric acid, rectification is performed, and the distillate at a temperature of 135 DEG C is collected so as to obtain the 1,1,1,3,3,5,5-heptamethyltrisiloxane product. According to the present invention, the method has characteristics of strong target property, less by-product content in the product, and easy separation.

Effect of catalyst structure on the reaction of α-methylstyrene with 1,1,3,3-tetramethyldisiloxane

Reaction of α-methylstyrene with 1,1,3,3-tetramethyldisiloxane in the presence of the complexes of platinum(II), palladium(II) and rhodium(I) is explored. It is established that in the presence of platinum catalyst predominantly occurs hydrosilylation of α-methylstyrene leading to formation of β-adduct, on palladium catalysts proceeds reduction of α-methylstyrene, on rhodium catalysts both the processes take place. In the reaction mixture proceeds disproportion and dehydrocondensation of 1,1,3,3-tetramethyldisiloxane that leads to formation of long chain linear and cyclic siloxanes of general formula HMe2Si(OSiMe2) n H and (-OSiMe2-)m (n = 2-6, m = 3-7), respectively. Platinum catalysts promotes formation of linear siloxanes, while both rhodium and palladium catalysts afford linear and cyclic siloxanes as well. Structure of intermediate metallocomplexes is studied.

Gas-phase reaction of free diethylsilylium ions with hexamethyldisiloxane

The gas-phase reaction of diethylsilylium ions with hexamethyldisiloxane was studied by the radiochemical procedure. As in reactions with other nucleophiles, the degree of rearrangement of the diethylsilylium ion in the reaction with hexamethyldisiloxane correlates with the condensation energy. In contrast to the reaction of Et2SiT+ with dibutyl ether, in the reaction with hexamethyldisiloxane the labeled substrate is formed, which is due to isomerization of the trimethylsilyl substituent giving rise to a labile hydrogen atom. 2005 Pleiades Publishing, Inc.

New route to permethylcyclosiloxanes

A new method for preparing permethylcyclosiloxanes, based on reaction of 1,1,3,3-tetramethyldisiloxane with iodine (molar ratio 1:1) in inert organic solvents (alkanes, alkyl halides, benzene) is proposed. The products of the reaction react with ethoxytrimethylsilane and tetramethoxysilane in hexamethyldisiloxane to give respectively pentamethyldisiloxane and products of successive substitution of the methoxy groups in Si(OMe)4 by Me2SiHO. A probable scheme of their formation is discussed.

Symetrical hydroxyphenyl-s-triazine compositions

The invention is concerned with compounds of formula I: STR1 which are useful as sun screening agents.

Hydrosilation of endo-cis-5-Norbornene-2,3-dicarboxylic Anhydride

In hydrosilation of endo-cis-5-norbornene-2,3-dicarboxyIic anhydride with pentamethyldisiloxane and heptamethyltrisiloxane catalyzed by platinum(II) complexes, the mixed complexes with amino and sulfoxide ligands are the most active. The differences between the activities of the exo and endo isomers were explained on the basis of quantum chemical calculations indicating significant difference in the frontal orbitals of the exo and endo derivatives of norbornenedicarboxylic anhydride and the corresponding imides. A lower activity of the endo isomers is due to a change in the structure of the lowest unoccupied molecular orbital and its weak π-acceptor interaction with the transition metal atom in the course of the catalytic cycle.

Reactions of lithium hydridosilylamides with carbonyl compounds and mixtures of carbonyl compounds and chlorotrimethylsilane

The lithium hydridosilylamides Me2(H)SiN(Li)R (1: R = CMe3, 2: R = SiMe3) were allowed to react either with the non-enolizable carbonyl compounds CH2=C(Me)CHO, PhCHO and Ph2CO followed by trapping with chlorotrimethylsilane (A), or with mixtures of these carbonyl compounds and chlorotrimethylsilane (B). In the second case the course of the reactions is determined by the carbonyl compound. The composition of the reaction mixtures is nearly the same according to A and B. Main products in the reactions with the aldehydes are the corresponding imines R1CH=NR R1 = CH2=C(Me), Ph) 3, 4, 8, 9 formed by addition of the hydridosilylamides to the C=O group of the aldehydes and subsequent LiOSiMe2H elimination. Partial hydrosilylation of the aldehydes by the hydridosilanolate followed by the trimethylsilylation yields the alkoxydisiloxanes R1CH2OSiMe2OSiMe3 6, 11. In some cases 2 partially reacts under hydrosilylation to give the alkoxydisilazanes R1CH2OSiMe2NHSiMe3 7, 12. The hydrosilylation is the preferred reaction of 1 and 2 with benzophenone. The compounds Ph2CHOSiMe2NHR 13, 14 are obtained. This difference in the reaction behaviour of 1 and 2 towards the aldehydes and benzophenone is mainly due to steric reasons. Depending on the conditions the imines Ph2C=NR 20, 21 may be formed. Ph2CHOSiMe2OSiMe3 (22) is a secondary product of imine formation. In all reactions of 1 and 2 with the carbonyl compounds the corresponding alkoxysilanes R1CH2OSiMe3 (5: R1 = CH2=C(Me), 6: R1 = Ph) and Ph2CHOSiMe3 (15) are generated. Compounds resulting from a reaction of 1 and 2 with chlorotrimethylsilane are produced to minor extent, but only if the molar ratio of amide to carbonyl compounds is not greater than one. The formation of a silanimine intermediate in reaction according to B is not observed.