18139-89-4

Basic information

• Product Name: 1,3,5,7,9-pentachloro-1,3,5,7,9-pentamethylcyclopentasiloxane
• Synonyms: 1,3,5,7,9-pentachloro-1,3,5,7,9-pentamethylcyclopentasiloxane
• CAS NO: 18139-89-4
• Molecular Weight: 472.864
• Mol File: 18139-89-4.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: 1,3,5,7,9-pentachloro-1,3,5,7,9-pentamethylcyclopentasiloxane(CAS DataBase Reference)
• NIST Chemistry Reference: 1,3,5,7,9-pentachloro-1,3,5,7,9-pentamethylcyclopentasiloxane(18139-89-4)
• EPA Substance Registry System: 1,3,5,7,9-pentachloro-1,3,5,7,9-pentamethylcyclopentasiloxane(18139-89-4)

Safety Data

• Hazardous Substances Data: 18139-89-4(Hazardous Substances Data)

Upstream product

• 75-79-6 Methyltrichlorosilane 
• 67-68-5 dimethyl sulfoxide 

Downstream Products

• 556-67-2 octamethylcyclotetrasiloxane 
• 541-02-6 decamethylcyclopentasiloxane 
• 540-97-6 dodecamethyl-cyclohexasiloxane 

Relevant articles and documents

Generation and capture of alkylchlorosilanones

Alkyltrichlorosilanes react with DMSO (molar ratio 1 : 1, 0 °C) to give cyclic oligoalkylchlorosiloxanes of the general formula [R(Cl)SiO]n (where R = Me or Et; n = 3-6). With an excess of alkyltrichlorosilane (2 : 1), linear oligoalkylchlorosiloxanes Cl[R(Cl)SiO]mSiCl2R (where R = Me or Et; m = 1-5) are also formed. In the presence of hexamethyldisiloxane (molar ratio Cl3SiR : DMSO : (Me3Si)2O = 1 : 1 : 2, 20 °C), the reaction products are both cyclic and linear oligoalkyl(trimethylsilyloxy)siloxanes [R(Me3SiO)SiO]n (n = 3-5) and Me3Si[OSi(OSiMe3)R]mOSiMe3 (m = 1-3), respectively. The reaction of DMSO with trichloro(vinyl)silane and hexamethyldisiloxane occurs in a similar manner. A plausible scheme of formation of the final products via intermediate alkylchlorosilanones RClSi=O and alkyl(trimethylsilyloxy)silanones is discussed.