Chemical Properties of Octadecamethyloctasiloxane

InChI

InChI=1S/C18H54O7Si8/c1-26(2,3)19-28(7,8)21-30(11,12)23-32(15,16)25-33(17,18)24-31(13,14)22-29(9,10)20-27(4,5)6/h1-18H3

InChI Key

VWGDPBQTSZDFMX-UHFFFAOYSA-N

Formula

C18H54O7Si8

SMILES

C[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)C

Molecular Weight¹

607.31

• ω : Acentric Factor.
• Δ_vapH : Enthalpy of vaporization at a given temperature (kJ/mol).
• IE : Ionization energy (eV).
• logP_oct/wat : Octanol/Water partition coefficient.
• P_c : Critical Pressure (kPa).
• P_vap : Vapor pressure (kPa).
• T_boil : Normal Boiling Point Temperature (K).
• T_c : Critical Temperature (K).
• V_c : Critical Volume (m³/kmol).
• Z_c : Critical Compressibility.
• ¹: Molecular weight from the IUPAC atomic weights tables.

Physical Properties

Property	Value	Unit	Source
ω	0.9959		PSRK revision IV (2005), critical constants and acentric factors of 1000 components Compiled value
IE	10.32	eV	Relay (1.0) Calculated Property
logPoct/wat	6.983		Crippen Calculated Property
Pc	[624.16; 680.00]	kPa
Pc	680.00	kPa	IUPAC Vapor-Liquid Critical Properties of Elements and Compounds, part 11 Compiled value
Pc	624.16	kPa	PSRK revision IV (2005), critical constants and acentric factors of 1000 components Compiled value
Tboil	558.29	K	Relay (1.0) Calculated Property
Tc	[688.90; 689.00]	K
Tc	689.00	K	IUPAC Vapor-Liquid Critical Properties of Elements and Compounds, part 11 Compiled value
Tc	688.90	K	PSRK revision IV (2005), critical constants and acentric factors of 1000 components Compiled value
Vc	[2.336; 2.466]	m3/kmol
Vc	2.336	m3/kmol	IUPAC Vapor-Liquid Critical Properties of Elements and Compounds, part 11 Compiled value
Vc	2.466	m3/kmol	PSRK revision IV (2005), critical constants and acentric factors of 1000 components Compiled value
Zc	0.2770000		IUPAC Vapor-Liquid Critical Properties of Elements and Compounds, part 11 Compiled value

Cheméo can also estimate Normal melting (fusion) point, Enthalpy of formation at standard conditions, Enthalpy of vaporization at standard conditions, Standard Gibbs free energy of formation, Log10 of Water solubility in mol/l for this compound, but they fall outside the models' validated range, so they are not shown here. Open the prediction tool to compute them on demand.

Temperature Dependent Properties

Property	Value	Unit	Temperature (K)	Source
ΔvapH	[67.70; 68.40]	kJ/mol	[470.50; 525.00]
ΔvapH	67.70	kJ/mol	470.50	NIST
ΔvapH	68.40	kJ/mol	525.00	NIST
Pvap	[7.27e-04; 1.19]	kPa	[338.15; 438.15]
Pvap	7.27e-04	kPa	338.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	1.85e-03	kPa	348.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	4.45e-03	kPa	358.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.01	kPa	368.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.02	kPa	378.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.05	kPa	388.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.10	kPa	398.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.19	kPa	408.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.36	kPa	418.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.67	kPa	428.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	1.19	kPa	438.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers

Similar Compounds

Find more compounds similar to Octadecamethyloctasiloxane.

Sources

• IUPAC Vapor-Liquid Critical Properties of Elements and Compounds, part 11 ChEDL chemicals 1.5.2, from Ambrose, D.; Tsonopoulos, C.; Nikitin, E. D. Vapor-Liquid Critical Properties of Elements and Compounds. 11. Organic Compounds Containing B + O; Halogens + N, + O, + O + S, + S, + Si; N + O; and O + S, + Si. J. Chem. Eng. Data 2009, 54, 669-689.
• PSRK revision IV (2005), critical constants and acentric factors of 1000 components ChEDL chemicals 1.5.2, from Horstmann, S.; Jabłoniec, A.; Krafczyk, J.; Fischer, K.; Gmehling, J. PSRK Group Contribution Equation of State: Comprehensive Revision and Extension IV, Including Critical Constants and α-Function Parameters for 1000 Components. Fluid Phase Equilib. 2005, 227, 157-164.
• Cheméo Relay (1.0)
• Cheméo Relay (1.0, beta) Beta: served but experimental, data-limited and below our cross-validation release bar; the Joback value is recommended where available.
• Crippen Method
• Crippen Method
• Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
• NIST Webbook

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