Chemical Properties of Cyclooctasiloxane, hexadecamethyl- (CAS 556-68-3)

InChI

InChI=1S/C16H48O8Si8/c1-25(2)17-26(3,4)19-28(7,8)21-30(11,12)23-32(15,16)24-31(13,14)22-29(9,10)20-27(5,6)18-25/h1-16H3

InChI Key

XKJMJYZFAWYREL-UHFFFAOYSA-N

Formula

C16H48O8Si8

SMILES

C[Si]1(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)O1

Molecular Weight¹

593.23

CAS

556-68-3

Other Names

• Hexadecamethyl-cyclooctasioxane
• Hexadecamethylcyclooctasiloxane

• Δ_vapH° : Enthalpy of vaporization at standard conditions (kJ/mol).
• Δ_vapH : Enthalpy of vaporization at a given temperature (kJ/mol).
• logP_oct/wat : Octanol/Water partition coefficient.
• P_vap : Vapor pressure (kPa).
• I_np : Non-polar retention indices.
• T_boil : Normal Boiling Point Temperature (K).
• T_c : Critical Temperature (K).
• T_fus : Normal melting (fusion) point (K).
• V_c : Critical Volume (m³/kmol).
• ¹: Molecular weight from the IUPAC atomic weights tables.

Physical Properties

Property	Value	Unit	Source
ΔvapH°	73.37	kJ/mol	Relay (1.0) Calculated Property
logPoct/wat	5.747		Crippen Calculated Property
Inp	[1688.00; 1712.00]
Inp	1693.00		NIST
Inp	1688.00		NIST
Inp	1709.00		NIST
Inp	1700.00		NIST
Inp	1700.00		NIST
Inp	1706.00		NIST
Inp	1706.00		NIST
Inp	1712.00		NIST
Inp	1712.00		NIST
Inp	1691.00		NIST
Inp	1688.00		NIST
Inp	1700.00		NIST
Inp	1712.00		NIST
Tboil	560.83	K	Relay (1.0) Calculated Property
Tc	668.32	K	Relay (1.0) Calculated Property
Tfus	242.00 ± 0.10	K	NIST
Vc	1.978	m3/kmol	Relay (1.0) Calculated Property

Cheméo can also estimate Enthalpy of formation at standard conditions, Standard Gibbs free energy of formation, Acentric Factor, Ionization energy, 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	[64.50; 66.60]	kJ/mol	[470.50; 515.00]
ΔvapH	66.60	kJ/mol	470.50	NIST
ΔvapH	64.50	kJ/mol	515.00	NIST
Pvap	[2.10e-03; 0.60]	kPa	[338.15; 418.15]
Pvap	2.10e-03	kPa	338.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	4.91e-03	kPa	348.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.01	kPa	358.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.02	kPa	368.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.05	kPa	378.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.09	kPa	388.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.18	kPa	398.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.33	kPa	408.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.60	kPa	418.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers

Similar Compounds

Find more compounds similar to Cyclooctasiloxane, hexadecamethyl-.

Sources

• 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

Note: Cheméo is only indexing the data, follow the source links to retrieve the latest data. The source is also providing more information like the publication year, authors and more. Take the time to validate and double check the source of the data.
These property values are available through the Cheméo API. A free account gives you an access key.