541-01-5

Basic information

• Product Name: hexadecamethylheptasiloxane
• Synonyms: Hepta(dimethylsiloxane);Hexadecamethyltridecaneheptasiloxane;bis[[[dimethyl(trimethylsilyloxy)silyl]oxy-dimethyl-silyl]oxy]-dimethyl-silane;bis[[[dimethyl(trimethylsilyloxy)silyl]oxy-dimethylsilyl]oxy]-dimethylsilane;hexadecamethylheptasiloxane Basic information;1,1,1,3,3,5,5,7,7,9,9,11,11,13,13,13-Hexadecamethylheptasiloxane
• CAS NO: 541-01-5
• Molecular Formula: C₁₆H₄₈O₆Si₇
• Molecular Weight: 533.1472
• EINECS: 208-763-3
• Mol File: 541-01-5.mol
• Article Data: 5

Chemical Properties

• Melting Point: -78°C
• Boiling Point: 286.79°C
• Flash Point: 168.9°C
• Appearance: /liquid
• Density: 0.9012
• Vapor Pressure: 0.0116mmHg at 25°C
• Refractive Index: 1.3965
• Storage Temp.: under inert gas (nitrogen or Argon) at 2-8°C
• CAS DataBase Reference: hexadecamethylheptasiloxane(CAS DataBase Reference)
• NIST Chemistry Reference: hexadecamethylheptasiloxane(541-01-5)
• EPA Substance Registry System: hexadecamethylheptasiloxane(541-01-5)

Safety Data

• Hazardous Substances Data: 541-01-5(Hazardous Substances Data)

Usage

General Description

Hexadecamethylheptasiloxane, also known as Squalane, is a type of silicone oil that is widely used in the cosmetics industry. It is a clear, odorless and non-greasy substance that is commonly added to moisturizers, sunscreens, hair care products, and makeup. Squalane helps to improve the spreadability and smoothness of products, and it also acts as a natural emollient, preventing moisture loss and keeping the skin hydrated. It has a lightweight and non-comedogenic nature, making it suitable for all skin types, including sensitive and acne-prone skin. Additionally, hexadecamethylheptasiloxane has been deemed safe for use in cosmetics by regulatory bodies, including the U.S. Food and Drug Administration (FDA) and the Cosmetic Ingredient Review (CIR) Expert Panel.

InChI:InChI=1/C16H48O6Si7/c1-23(2,3)17-25(7,8)19-27(11,12)21-29(15,16)22-28(13,14)20-26(9,10)18-24(4,5)6/h1-16H3

Synthetic route

1,1,1,3,3-pentamethyl-3-acetoxydisiloxane (70693-47-9) + undecamethylpentasiloxane-1-ol → hexadecamethylheptasiloxane (541-01-5)

Conditions	Yield
With triethylamine In dichloromethane at 25℃;	95%
triethylamine In dichloromethane at 29℃; Rate constant; Mechanism;	95%

octamethylcyclotetrasiloxane (556-67-2) → tetramethylsilane (75-76-3) + trimethylsilyl iodide (16029-98-4) + Hexamethyldisiloxane (107-46-0) + hexadecamethylheptasiloxane (541-01-5)

Conditions	Yield
With gallium(III) iodide at 140 - 170℃; for 5h; Yield given; Title compound not separated from byproducts;	A 61% B n/a C n/a D n/a

1,1,1,3,3-pentamethyl-3-acetoxydisiloxane (70693-47-9) + undecamethylpentasiloxane-1-ol → docosamethyl-decasiloxane (556-70-7) + hexadecamethylheptasiloxane (541-01-5)

Conditions	Yield
With trifluorormethanesulfonic acid In dichloromethane at 25℃;	A 32% B 35.5%
With trifluorormethanesulfonic acid In dichloromethane Mechanism; Ambient temperature;	A 32% B 35.5%

Hexamethyldisiloxane (107-46-0) + <(CH3)2SiO>n → hexadecamethylheptasiloxane (541-01-5) + octadecamethyl-octasiloxan, eicosamethyl-nonasiloxane, docosamethyl-decasiloxane and tetracosamethyl-undecasiloxane

Conditions	Yield
With sulfuric acid

ethyl trimethylsilyl ether (1825-62-3) + diethoxy dimethylsilane (78-62-6) → hexadecamethylheptasiloxane (541-01-5) + tetradecamethyl-hexasiloxan, octadecamethyl-octasiloxan, eicosamethyl-nonasiloxane, docosamethyl-decasiloxane and tetracosamethyl-undecasiloxane

Conditions	Yield
With hydrogenchloride
With sodium hydroxide
With hydrogenchloride
With sodium hydroxide

1-chloro-1,1,3,3,3-pentamethyldisiloxane (2943-62-6) → hexadecamethylheptasiloxane (541-01-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: 90 percent / 5 h 2: 35.5 percent / CF3SO3H / CH2Cl2 / Ambient temperature View Scheme
Multi-step reaction with 2 steps 1: 90 percent / 5 h 2: 95 percent / Et3N / CH2Cl2 / 29 °C View Scheme

ethyl trimethylsilyl ether (1825-62-3) + diethoxy dimethylsilane (78-62-6) → Octamethyltrisiloxane (107-51-7) + decamethyltetrasiloxane (141-62-8) + dodecamethylpentasiloxane (141-63-9) + tetradecamethylhexasiloxane (107-52-8) + hexadecamethylheptasiloxane (541-01-5)

Conditions	Yield
With NaOH In water byproducts: C2H5OH; heating of (CH3)2Si(OC2H5)2, (CH3)3Si(OC2H5) and an excess (50%) of H2O in presence of NaOH; sepn. of C2H5OH by distn.; boiling of the residue with 20% aq. HCl; further products;; distn.;;

Hexamethyldisiloxane (107-46-0) + octamethylcyclotetrasiloxane (556-67-2) → Octamethyltrisiloxane (107-51-7) + decamethyltetrasiloxane (141-62-8) + dodecamethylpentasiloxane (141-63-9) + tetradecamethylhexasiloxane (107-52-8) + hexadecamethylheptasiloxane (541-01-5)

Conditions	Yield
With sulfuric acid; antimony(V) chloride In tetrachloromethane; sulfuric acid shaking of (CH3)3SiOSi(CH3)3 and ((CH3)2SiO)4 (1:1 mol) with concd. H2SO4 at 25°C for 8 days; equilibrium react.; further products;;
With sulfuric acid In sulfuric acid shaking of (CH3)3SiOSi(CH3)3 and ((CH3)2SiO)4 (1:1 mol) with concd. H2SO4 at room temp. for 5 h; equilibrium react.; further products;;
With H2SO4 In sulfuric acid aq. H2SO4; shaking of (CH3)3SiOSi(CH3)3 and ((CH3)2SiO)4 (1:1 mol) with concd. H2SO4 at room temp. for 5 h; equilibrium react.; further products;;
With H2SO4; antimony(V) chloride In tetrachloromethane; sulfuric acid aq. H2SO4; shaking of (CH3)3SiOSi(CH3)3 and ((CH3)2SiO)4 (1:1 mol) with concd. H2SO4 at 25°C for 8 days; equilibrium react.; further products;;

Upstream product

• 1825-62-3 ethyl trimethylsilyl ether 
• 78-62-6 diethoxy dimethylsilane 
• 1560-28-7 pentamethylchlorodisilane 
• 107-46-0 Hexamethyldisiloxane 
• 556-67-2 octamethylcyclotetrasiloxane 
• 2943-62-6 1-chloro-1,1,3,3,3-pentamethyldisiloxane 
• 70693-47-9 1,1,1,3,3-pentamethyl-3-acetoxydisiloxane 

Relevant articles and documents

Kinetics of the condensation of oligosiloxanes containing acetoxyl and hydroxyl end groups catalyzed by uncharged nucleophiles in an acid-base inert solvent

Condensation of undecamethylpentasiloxane-1-ol (1) with 1-acetoxypentamethyldisiloxane (2) in methylene chloride in the presence of uncharged bases has been studied as a model for the coupling of acetoxyl and hydroxyl ended polydimethylsiloxane chains.Triethylamine acts not only as the acceptor of the acid released in the process but also as a Broensted base catalyst activating silanol group.However, weakly basic but strongly nucleophilic N-heterocycles such as 4-dimethylaminopyridine are more effective catalysts promoting the condensation by acting as nucleophiles to activate the acetoxysilane.

COSMETIC PROCESS FOR MAKING-UP AND/OR CARING FOR THE SKIN AND/OR THE LIPS

A cosmetic process for making-up and/or caring for skin and/or lips, includes the application to skin and/or lips of a cosmetic composition including, in a physiologically acceptable medium, at least one supramolecular polymer and at least one hydrophobic film-forming polymer. Particular compositions may be used in the process.

Reaction of Octamethylcyclotetrasiloxane with Aluminum, Gallium, and Silicon Iodides

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