Chemical Properties of Cyclononasiloxane, octadecamethyl- (CAS 556-71-8)

InChI

InChI=1S/C18H54O9Si9/c1-28(2)19-29(3,4)21-31(7,8)23-33(11,12)25-35(15,16)27-36(17,18)26-34(13,14)24-32(9,10)22-30(5,6)20-28/h1-18H3

InChI Key

ISXOGOLHEGHGQF-UHFFFAOYSA-N

Formula

C18H54O9Si9

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)O[Si](C)(C)O1

Molecular Weight¹

667.39

CAS

556-71-8

Other Names

• Octadeamethyl-cyclononasiloxane
• octadecamethylcyclononasiloxane

• Δ_fusH : Enthalpy of fusion at a given temperature (kJ/mol).
• 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°	76.79	kJ/mol	Relay (1.0) Calculated Property
logPoct/wat	6.466		Crippen Calculated Property
Inp	[1855.00; 1874.00]
Inp	1858.00		NIST
Inp	1858.00		NIST
Inp	1871.00		NIST
Inp	1865.00		NIST
Inp	1866.00		NIST
Inp	1868.00		NIST
Inp	1869.00		NIST
Inp	1874.00		NIST
Inp	1855.00		NIST
Inp	1865.00		NIST
Inp	1874.00		NIST
Tboil	585.66	K	Relay (1.0) Calculated Property
Tc	683.28	K	Relay (1.0) Calculated Property
Tfus	250.00 ± 1.00	K	NIST
Vc	2.215	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
ΔfusH	25.64	kJ/mol	246.20	NIST
ΔvapH	[67.90; 68.00]	kJ/mol	[523.50; 525.50]
ΔvapH	67.90	kJ/mol	523.50	NIST
ΔvapH	68.00	kJ/mol	525.50	NIST
Pvap	[4.73e-04; 0.23]	kPa	[338.15; 418.15]
Pvap	4.73e-04	kPa	338.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	1.20e-03	kPa	348.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	2.89e-03	kPa	358.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	6.63e-03	kPa	368.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.01	kPa	378.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.03	kPa	388.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.06	kPa	398.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.12	kPa	408.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.23	kPa	418.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers

Similar Compounds

Find more compounds similar to Cyclononasiloxane, octadecamethyl-.

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

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