Octamethylcyclotetrasiloxane Names Preferred IUPAC name Octamethyl-1,3,5,7,2,4,6,8-tetroxatetrasilocane Other names D4, OMCTS Identifiers CAS Number 556-67-2 Y 3D model (JSmol) Interactive image ChEBI CHEBI:25640 ChemSpider 10696 ECHA InfoCard 100.008.307 EC Number 209-136-7 PubChem CID 11169 UNII CZ227117JE Y CompTox Dashboard (EPA) DTXSID7027205 InChI InChI=1S/C8H24O4Si4/c1-13(2)9-14(3,4)11-16(7,8)12-15(5,6)10-13/h1-8H3 Key: HMMGMWAXVFQUOA-UHFFFAOYSA-N SMILES C[Si]1(O[Si](O[Si](O[Si](O1)(C)C)(C)C)(C)C)C Properties Chemical formula C8H24O4Si4 Molar mass 296.62 Density 0.956 g/mL Melting point 17–18 °C (63–64 °F; 290–291 K) Boiling point 175–176 °C (347–349 °F; 448–449 K) Solubility in water 56.2±2.5 ppb (23 °C)[1] log P 6.98±0.13[2] Vapor pressure 124.5±6.2 Pa (25 °C)[3] Hazards GHS labelling: Pictograms [4] Signal word Warning Hazard statements H361f, H410 M=10[4] Related compounds Related compounds Disiloxane Tetramethylsilane Dimethyl ether Bis(trimethylsilyl)amine Tetrakis(trimethylsilyloxy)silane Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references Chemical compound