107-50-6

Usage

Uses

Used in Cosmetic and Personal Care Products:
Tetradecamethylcycloheptasiloxane is used as an ingredient in the cosmetic and personal care industry for its ability to provide a smooth and silky texture to products. It is commonly found in skincare products, hair care products, and other personal care items, enhancing their performance and user experience.

InChI:InChI=1/C14H42O7Si7/c1-22(2)15-23(3,4)17-25(7,8)19-27(11,12)21-28(13,14)20-26(9,10)18-24(5,6)16-22/h1-14H3

Upstream product

• 78-62-6 diethoxy dimethylsilane 
• 75-78-5 dimethylsilicon dichloride 
• 541-05-9 Hexamethylcyclotrisiloxane 
• 1529-17-5 phenyltrimethylsilyl ether 
• 3277-26-7 1,1,3,3-Tetramethyldisiloxane 
• 540-97-6 dodecamethyl-cyclohexasiloxane 
• 74-83-9 methyl bromide 
• 115-10-6 Dimethyl ether 
• 7440-21-3 silicon 
• 18642-94-9 1,1,2,2-tetramethyl-1,2-di-n-octyldisiloxane 
• 98-83-9 isopropenylbenzene 
• 109-72-8 n-butyllithium 
• 4342-61-4 1,2-dichlorotetramethylsilane 
• 3004-00-0 α,ω-Dichlor-tetradecamethyl-heptasiloxan 

Relevant academic research and scientific papers

Siloxane-bridged [n]troticenophanes: Syntheses, structures and ring-opening reactions

Salt elimination reactions between dilithiotroticene [(η7- C7H6Li)Ti(η5-C5H 4Li)]·pmdta (1) (pmdta = N,N′ ,N′ ,N″ ,N″-pentamethyldiethylenetriamine) and siloxane dichlorides ClMe 2Si-(OSiMe2)m-Cl (m = 1-3) at low temperature allowed the synthesis and isolation of the siloxane-bridged [n]troticenophanes [(η7-C7H6)Ti(η5-C 5H4)](OSiMe2)m(SiMe2) (2, m = 1; 3, m = 2; 4, m = 3) as blue crystalline solids in moderate yield. The compounds were characterized by 1H, 13C and 29Si NMR spectroscopy, elemental and single-crystal X-ray diffraction analyses. The molecular structures of 2 and 3 showed a low degree of strain indicated by the dihedral (α= 4.8° for 2; 4.9/3.7° for 3) and distortion (δ = 176.2° for 2; 174.3/176.3° for 3) angles between the two rings. The structure of 4 was severely disordered. Compounds 2-4 are thermally resistant to ring-opening polymerization, as revealed by differential scanning calorimetry studies, with 2 exhibiting the higher melting temperature. Moreover, the observation of two endotherms in the DSC spectrum of 2 suggests a solid state transition as a result of polymorphism. The reactions of 2-4 with basic initiators such as potassium siloxanolate, ammonium siloxanolate or n-BuLi and analysis of the product distribution by electron ionization mass spectrometry revealed the formation of oligotroticenylsiloxanes incorporating one or more troticenyl units, ring-opened troticenes and ringexpanded troticenophanes [(η7-C7H6) Ti(η 5-C5H4)](OSiMe 2)r(SiMe2) (r > m). Similar cleavage and extension of the ring were observed by treatment of 2-4 with the acidic initiator Purolite CT-175, and ring-opened troticenes having mixed terminal -OH and -SiMe3 groups were detected. Attempts to copolymerize 2-4 and cyclotrisiloxane with n-BuLi afforded essentially the monomeric and polymeric siloxanes [Me2SiO]w (w = 7, 8), Me2(nBu) Si[OSiMe2]yOSiMe2 (y = 3-6) and Me 2(n-Bu)Si[OSiMe2]zOH (z = 1-7), together with the ring-opened and ring-expanded products mentioned above.

Hydrogenolysis of Polysilanes Catalyzed by Low-Valent Nickel Complexes

The dehydrogenation of organosilanes (RxSiH4?x) under the formation of Si?Si bonds is an intensively investigated process leading to oligo- or polysilanes. The reverse reaction is little studied. To date, the hydrogenolysis of Si?Si bonds requires very harsh conditions and is very unselective, leading to multiple side products. Herein, we describe a new catalytic hydrogenation of oligo- and polysilanes that is highly selective and proceeds under mild conditions. New low-valent nickel hydride complexes are used as catalysts and secondary silanes, RR′SiH2, are obtained as products in high purity.

METHOF FOR PRODUCING HYDRIDOSILANES

The invention relates to a method for producing hydridosilanes, in which siloxanes containing Si—H groups are reacted in the presence of a cationic Si(II) compound as a catalyst.

High-efficiency macrocyclic dimethyl siloxane compound preparation method

The invention discloses a high-efficiency macrocyclic dimethyl siloxane compound preparation method which comprises the following steps: (1) utilizing tetramethyl disiloxane and octamethyl cyclotetrasiloxane as raw materials, performing ring-openingopen cycle in a sodium hydroxide or potassium hydroxide water solution and then inserting again to obtain dimethyl hydrogen silicone end capped direct-linked siloxane; (2) chlorinating the dimethyl hydrogen silicone end capped direct-linked siloxane with acetyl chloride under a catalytic effect of aluminum trichloride to obtain dimethyl chlorosilane end capped direct-linked siloxane; (3) hydrolyzing the direct-linked siloxane under the alkali condition to obtain varieties of macrocyclic diemthyl silicon ring bodies. The preparation method has simple steps and economical and safe technology and can be used for obtaining varieties of high-purity macrocyclic diemthyl silicon ring body products from simple raw materials; thus, high-difficulty distillation is avoided, and the preparation method is very suitable for industrial production.

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.

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.

METHOD FOR THE PRODUCTION OF CYCLIC POLYSILOXANES

A process for producing cyclic polysiloxanes is disclosed. The first step of the process comprises combining a poiysiloxane, a cafaiyst and a high boiling endblocker, wherein the catalyst is selected from the group consisting of a phosphazene base and a carborane acid. The second step of the process comprises heating said poiysiloxane, catalyst and high boiling endblocker, and the third step of the process comprising recovering the cyclic poiysiloxane,

Novel direct process

The invention relates to continuous processes for making cyclic dimethylsiloxane oligomers by reacting in situ methyl bromide, dimethyl ether and activated silicon particles in a direct process reaction zone to produce methylsiloxanes, wherein the proportion of dimethylsiloxane produced in said reaction zone is greater than 75 mole % of the methylsiloxanes produced and recovering the dimethylsiloxane from the reactions zone. The invention favors making cyclic dimethylsiloxane oligomers by this in situ direct reaction.

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.