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

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

Uses

Used in Cosmetics Industry:
Hexadecamethylheptasiloxane is used as a moisturizing agent for its ability to prevent moisture loss and keep the skin hydrated.
Hexadecamethylheptasiloxane is used as an emollient for its natural properties that improve the spreadability and smoothness of cosmetic products.
Used in Moisturizers:
Hexadecamethylheptasiloxane is used as a key ingredient in moisturizers for its hydrating and non-greasy nature, making it suitable for all skin types.
Used in Sunscreens:
Hexadecamethylheptasiloxane is used as a carrier in sunscreens to enhance the product's spreadability and provide a smooth application.
Used in Hair Care Products:
Hexadecamethylheptasiloxane is used in hair care products to improve the texture and manageability of hair, providing a non-greasy and lightweight feel.
Used in Makeup:
Hexadecamethylheptasiloxane is used in makeup products to ensure a smooth and even application, as well as to prevent clogging of pores.

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

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

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.

One-Step Synthesis of Siloxanes from the Direct Process Disilane Residue

The well-established Müller–Rochow Direct Process for the chloromethylsilane synthesis produces a disilane residue (DPR) consisting of compounds MenSi2Cl6?n(n=1–6) in thousands of tons annually. Technologically, much effort is made to retransfer the disilanes into monosilanes suitable for introduction into the siloxane production chain for increase in economic value. Here, we report on a single step reaction to directly form cyclic, linear, and cage-like siloxanes upon treatment of the DPR with a 5 m HCl in Et2O solution at about 120 °C for 60 h. For simplification of the Si?Si bond cleavage and aiming on product selectivity the grade of methylation at the silicon backbone is increased to n≥4. Moreover, the HCl/Et2O reagent is also suitable to produce siloxanes from the corresponding monosilanes under comparable conditions.

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.

COSMETIC COMPOSITION BASED ON A SUPRAMOLECULAR POLYMER AND A SILICONE COMPOUND

The present invention relates to a process for making up and/or caring for the skin and/or the lips, comprising the application to the skin and/or the lips of a cosmetic composition and in particular a composition for making up and/or caring for the skin and/or the lips, comprising at least one supramolecular polymer and a silicone compound with a viscosity of less than 10 000 000 cSt at 25° C.