The CAS register number of Trisiloxane,1,1,1,3,5,5,5-heptamethyl-3-octyl- is 17955-88-3. It also can be called as Caprylyl methicone and the systematic name about this chemical is 1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane. The molecular formula about this chemical is C₁₅H₃₈O₂Si₃ and the molecular weight is  334.72.

Physical properties about Trisiloxane,1,1,1,3,5,5,5-heptamethyl-3-octyl- are: (1)ACD/LogP: 8.46; (2)# of Rule of 5 Violations: 1; (3)ACD/LogD (pH 5.5): 8.46; (4)ACD/LogD (pH 7.4): 8.46; (5)ACD/BCF (pH 5.5): 1000000; (6)ACD/BCF (pH 7.4): 1000000; (7)ACD/KOC (pH 5.5): 950258.69; (8)ACD/KOC (pH 7.4): 950258.69; (9)#H bond acceptors: 2; (10)#Freely Rotating Bonds: 11; (11)Polar Surface Area: 18.46 Å²; (12)Index of Refraction: 1.424; (13)Molar Refractivity: 101.18 cm³; (14)Molar Volume: 396 cm³; (15)Polarizability: 40.11x10^-24cm³; (16)Surface Tension: 20.7 dyne/cm; (17)Density: 0.845 g/cm³; (18)Flash Point: 124.9 °C; (19)Enthalpy of Vaporization: 52.74 kJ/mol; (20)Boiling Point: 308.6 °C at 760 mmHg; (21)Vapour Pressure: 0.00122 mmHg at 25 °C.

You can still convert the following datas into molecular structure:
(1)SMILES: O([Si](C)(C)C)[Si](O[Si](C)(C)C)(CCCCCCCC)C
(2)InChI: InChI=1/C15H38O2Si3/c1-9-10-11-12-13-14-15-20(8,16-18(2,3)4)17-19(5,6)7/h9-15H2,1-8H3
(3)InChIKey: SCRSFLUHMDMRFP-UHFFFAOYAF
(4)Std. InChI: InChI=1S/C15H38O2Si3/c1-9-10-11-12-13-14-15-20(8,16-18(2,3)4)17-19(5,6)7/h9-15H2,1-8H3
(5)Std. InChIKey: SCRSFLUHMDMRFP-UHFFFAOYSA-N