18297-87-5

Basic information

• Product Name: Trisiloxane, 1-chloro-1,1,3,3,5,5,5-heptamethyl-
• Synonyms: 1-chloroheptamethyltrisiloxane;Trisiloxane,1-chloro-1,1,3,3,5,5,5-heptamethyl
• CAS NO: 18297-87-5
• Molecular Formula: C7H21ClO2Si3
• Molecular Weight: 256.952
• Mol File: 18297-87-5.mol
• Article Data: 5

Chemical Properties

• CAS DataBase Reference: Trisiloxane, 1-chloro-1,1,3,3,5,5,5-heptamethyl-(CAS DataBase Reference)
• NIST Chemistry Reference: Trisiloxane, 1-chloro-1,1,3,3,5,5,5-heptamethyl-(18297-87-5)
• EPA Substance Registry System: Trisiloxane, 1-chloro-1,1,3,3,5,5,5-heptamethyl-(18297-87-5)

Safety Data

• Hazardous Substances Data: 18297-87-5(Hazardous Substances Data)

Upstream product

• 75-77-4 chloro-trimethyl-silane 
• 67078-75-5 2,2-dimethyl-1-oxa-2-silacyclohexa-3,5-diene 
• 80431-43-2 2,2-Dimethyl-4,4-diphenyl-3,3-bis(trimethylsilyl)-1-oxa-2-silacyclobutan 
• 93-59-4 Perbenzoic acid 
• 918-19-4 1-chloroheptamethyltrisilane 
• 107-46-0 Hexamethyldisiloxane 
• 2943-62-6 1-chloro-1,1,3,3,3-pentamethyldisiloxane 

Relevant articles and documents

Siloxanes as sources of silanones

Pyrolysis of hexamethyldisiloxane (HMDS) and its copyrolysis with chlorotrimethylsilane and tetrachlorosilane were studied. Based on the data of GLC analysis and on the mass spectrum of the condensate obtained after the pyrolysis of HMDS, it was concluded that HMDS acts as a source of dimethylsilanone. The results of the copyrolysis of HMDS with chlorotrimethylsilane used as a trapping reagent indicate that the dimethylsilanone generated from HMDS can be inserted into the Si-Cl and Si-O bonds. In the copyrolysis of HMDS with tetrachlorosilane serving as a trapping reagent for dimethylsilanone, both dimethylsilanone and dichlorosilanone are generated.

Storing of the Labile Silaethene Me2Si=C(SiMe3)2 with Benzophenone

Benzophenone Ph2C=O is able to "store" the silaethene Me2Si=C(SiMe3)2 (1), produced from Me2SiX-CLi(SiMe3)2 (X = F, Br, Ph2PO4), under formation of a cycloadduct (2b).At about 100 deg C, 2b by way of 1 transfers into the cycloadduct of 1 and Ph2C=O (3b), which in the course of transformation decomposes visibly (in the absence of Me3SiCl) or only by traces (in the presence of Me3SiCl) to secondary products.In the presence of ROH (R = H, Me, tBu, MeCO) or PhN=NSiMe3 or RN3 (R = tBu, Me3Si) or 2,3-dimethylbutadiene (dmb) about 100 deg C 2b and 3b form by way of 1 insertion products of 1 into the OH bond of ROH or a cycloadduct of 1 and PhN=NSiMe3 or cycloadducts of 1 and RN3 or cycloadduct and an ene reaction product of 1 and dmb.The rate constants/half lives of the first order transformation of 2b into 3b or of the first order decomposition of 2b or of 3b in the presence of reactive traps for 1 (ROH, Me3SiN3; benzene as solvent) are in the order of 0.3E-4 s-1/τ1/2 = 7 h (2b --> 3b; 90 deg C) 3E-4 s-1/τ1/2 = 3/4 h (2b + traps; 90 deg C), 0.4E-4 s-1/τ1/2 = 5 h (3b + traps, 110 deg C). - Keywords: Silaethene Me2Si=C(SiMe3)2, Insertions, Cycloadditions, Kinetic Studies

Direct Thermal and Photochemical Generation of Silanones

2-Silapyrans (1,2-oxasilins) are synthesized by the pyrolysis of 1-disilanyl-4-methoxy-1,3-butadienes via initial 1,5-silyl migration to afford an intermediate 1-sila-1,3-butadiene.Diels-Alder reaction of the silapyrans and perfluoro-2-butyne does not lead to isolable adducts but rather leads to apparent extrusion of silanone (R2Si=O), which is trapped by a variety of reagents.Reaction of the silapyrans and maleic anhydride provides stable adducts that extrude silanones upon either thermolysis or photolysis.No evidence could not be found for rearrangement of a silylsilanone to a siloxysilylene.