Chemical Properties of Cyclotetrasiloxane, octamethyl- (CAS 556-67-2)

InChI

InChI=1S/C8H24O4Si4/c1-13(2)9-14(3,4)11-16(7,8)12-15(5,6)10-13/h1-8H3

InChI Key

HMMGMWAXVFQUOA-UHFFFAOYSA-N

Formula

C8H24O4Si4

SMILES

C[Si]1(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O1

Molecular Weight¹

296.62

CAS

556-67-2

Other Names

• CO9810
• Cyclotetrasilane, octamethyl
• D4 (octamethylcyclotetrasiloxane)
• NUC Silicone VS 7207
• O9810
• Octamethylcyclotetrasiloxane
• Octamethyltetrasiloxane
• Oktamethylcyklotetrasiloxan

• ω : Acentric Factor.
• C_p,liquid : Liquid phase heat capacity (J/mol×K).
• Δ_fG° : Standard Gibbs free energy of formation (kJ/mol).
• Δ_fH°_gas : Enthalpy of formation at standard conditions (kJ/mol).
• 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).
• IE : Ionization energy (eV).
• log₁₀WS : Log10 of Water solubility in mol/l.
• logP_oct/wat : Octanol/Water partition coefficient.
• P_c : Critical Pressure (kPa).
• P_vap : Vapor pressure (kPa).
• ρ_c : Critical density (kg/m³).
• ρ_l : Liquid Density (kg/m³).
• I_np : Non-polar retention indices.
• c_sound,fluid : Speed of sound in fluid (m/s).
• T_boil : Normal Boiling Point Temperature (K).
• T_c : Critical Temperature (K).
• T_fus : Normal melting (fusion) point (K).
• T_triple : Triple Point Temperature (K).
• V_c : Critical Volume (m³/kmol).
• V_m : Molar Volume (m³/mol).
• ¹: Molecular weight from the IUPAC atomic weights tables.

Contents

1. Physical Properties
2. Temperature Dependent Properties
3. Datasets
4. Correlations
5. Similar Compounds
6. Mixtures
7. Sources

Physical Properties

Property	Value	Unit	Source
ω	0.4499		Relay (1.0) Calculated Property
ΔfG°	-319.77	kJ/mol	Relay (1.0-beta) Calculated Property
ΔfH°gas	-1266.09	kJ/mol	Relay (1.0) Calculated Property
ΔvapH°	[56.10; 57.00]	kJ/mol
ΔvapH°	57.00 ± 0.80	kJ/mol	NIST
ΔvapH°	56.10	kJ/mol	NIST
IE	9.85	eV	Relay (1.0) Calculated Property
log10WS	-2.05		Relay (1.0) Calculated Property
logPoct/wat	2.874		Crippen Calculated Property
Pc	[1320.00; 1339.59]	kPa
Pc	1320.00 ± 20.00	kPa	NIST
Pc	1339.59 ± 6.86	kPa	NIST
ρc	295.13 ± 2.94	kg/m3	NIST
Inp	[994.00; 1022.00]
Inp	1004.00		NIST
Inp	994.00		NIST
Inp	1022.00		NIST
Inp	1010.00		NIST
Inp	1010.00		NIST
Inp	1011.00		NIST
Inp	1013.00		NIST
Inp	1017.00		NIST
Inp	1017.00		NIST
Inp	1000.00		NIST
Inp	1004.00		NIST
Tboil	[446.20; 448.50]	K
Tboil	448.50 ± 0.50	K	NIST
Tboil	446.20 ± 0.60	K	NIST
Tc	[585.70; 586.50]	K
Tc	585.70 ± 0.30	K	NIST
Tc	586.50 ± 0.20	K	NIST
Tfus	[287.40; 290.65]	K
Tfus	290.00 ± 0.10	K	NIST
Tfus	290.65 ± 0.20	K	NIST
Tfus	287.40 ± 0.10	K	NIST
Ttriple	[23.76; 290.25]	K
Ttriple	290.25 ± 0.02	K	NIST
Ttriple	23.76 ± 0.04	K	NIST
Vc	[0.984; 1.005]	m3/kmol
Vc	1.005 ± 0.001	m3/kmol	NIST
Vc	0.984 ± 0.003	m3/kmol	NIST
Vm	3.12e-04	m3/mol	Thermodynamic Study of Heptane + Silicone Mixtures. Excess Volumes and Enthalpies at 298.15 K

Temperature Dependent Properties

Property	Value	Unit	Temperature (K)	Source
Cp,liquid	[511.50; 568.40]	J/mol×K	[293.15; 425.95]
Cp,liquid	511.50	J/mol×K	293.15	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	513.60	J/mol×K	298.00	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	515.80	J/mol×K	303.15	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	517.20	J/mol×K	306.25	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	520.10	J/mol×K	313.12	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	522.70	J/mol×K	319.00	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	524.50	J/mol×K	323.25	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	526.40	J/mol×K	327.55	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	529.10	J/mol×K	334.75	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	530.80	J/mol×K	337.88	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	532.70	J/mol×K	342.23	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	535.20	J/mol×K	348.05	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	538.80	J/mol×K	352.20	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	539.90	J/mol×K	358.83	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	542.20	J/mol×K	364.28	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	543.00	J/mol×K	370.25	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	548.00	J/mol×K	377.55	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	550.10	J/mol×K	382.48	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	552.30	J/mol×K	388.65	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	554.70	J/mol×K	393.15	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	557.70	J/mol×K	399.83	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	560.80	J/mol×K	407.15	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	564.50	J/mol×K	415.73	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
Cp,liquid	568.40	J/mol×K	425.95	Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
ΔfusH	23.77	kJ/mol	290.50	NIST
ΔvapH	[44.10; 48.50]	kJ/mol	[365.50; 415.00]
ΔvapH	48.50	kJ/mol	365.50	NIST
ΔvapH	45.60	kJ/mol	365.50	NIST
ΔvapH	44.10	kJ/mol	378.50	NIST
ΔvapH	47.60	kJ/mol	415.00	NIST
Pvap	[0.24; 5.11]	kPa	[308.15; 368.15]
Pvap	0.24	kPa	308.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.43	kPa	318.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	0.75	kPa	328.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	1.26	kPa	338.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	2.06	kPa	348.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	3.29	kPa	358.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
Pvap	5.11	kPa	368.15	Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
ρl	[915.80; 956.03]	kg/m3	[293.15; 328.15]
ρl	956.03	kg/m3	293.15	The mixing properties of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl) cyclotrisiloxane with various organosilicon compounds at different temperatures
ρl	938.83	kg/m3	308.15	The mixing properties of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl) cyclotrisiloxane with various organosilicon compounds at different temperatures
ρl	938.88	kg/m3	308.15	Volumetric and refractive properties of the mixtures of 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane with various organosilicon compounds at T = (308.15 to 328.15) K
ρl	933.13	kg/m3	313.15	The mixing properties of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl) cyclotrisiloxane with various organosilicon compounds at different temperatures
ρl	933.06	kg/m3	313.15	Volumetric and refractive properties of the mixtures of 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane with various organosilicon compounds at T = (308.15 to 328.15) K
ρl	927.38	kg/m3	318.15	The mixing properties of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl) cyclotrisiloxane with various organosilicon compounds at different temperatures
ρl	927.34	kg/m3	318.15	Volumetric and refractive properties of the mixtures of 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane with various organosilicon compounds at T = (308.15 to 328.15) K
ρl	921.62	kg/m3	323.15	The mixing properties of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl) cyclotrisiloxane with various organosilicon compounds at different temperatures
ρl	921.59	kg/m3	323.15	Volumetric and refractive properties of the mixtures of 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane with various organosilicon compounds at T = (308.15 to 328.15) K
ρl	915.91	kg/m3	328.15	The mixing properties of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl) cyclotrisiloxane with various organosilicon compounds at different temperatures
ρl	915.80	kg/m3	328.15	Volumetric and refractive properties of the mixtures of 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane with various organosilicon compounds at T = (308.15 to 328.15) K

Datasets

Speed of sound, m/s

Fixed		Measured
Temperature, K - Fluid (supercritical or subcritical phases)	Pressure, kPa - Fluid (supercritical or subcritical phases)	Speed of sound, m/s - Fluid (supercritical or subcritical phases)
450.00	38.90	110.351
450.00	46.70	109.656
450.00	57.41	108.801
450.00	62.89	108.299
450.00	69.33	107.727
465.00	31.29	113.043
465.00	32.63	112.986
465.00	36.51	112.753
465.00	40.99	112.32
465.00	46.84	111.935
465.00	47.85	111.913
465.00	49.18	111.723
465.00	57.21	111.202
465.00	58.99	110.976
465.00	61.46	110.824
465.00	68.51	110.332
465.00	70.69	110.062
465.00	73.59	109.872
465.00	74.87	109.829
465.00	77.48	109.53
465.00	81.72	109.278
465.00	87.87	108.72
465.00	92.89	108.286
465.00	97.68	107.963
465.00	101.01	107.535
465.00	105.11	107.277
465.00	106.95	107.179
465.00	111.40	106.695
465.00	116.93	106.3
465.00	121.67	105.761
465.00	123.48	105.664
480.00	42.70	114.022
480.00	54.67	113.202
480.00	65.08	112.478
480.00	71.30	112.038
480.00	85.50	111.071
480.00	92.46	110.502
480.00	109.21	109.241
480.00	118.88	108.493
480.00	129.21	107.675
480.00	140.39	106.769
480.00	152.36	105.769
480.00	165.42	104.642
495.00	27.45	117.135
495.00	36.20	116.658
495.00	47.54	115.985
495.00	143.41	109.744
495.00	159.70	108.434
495.00	160.40	108.391
495.00	174.53	107.346
495.00	186.64	106.439
495.00	198.61	105.492
495.00	224.52	103.408
Reference

Operational condition: Frequency, MHz = 8 (Liquid)

Fixed		Measured
Temperature, K - Liquid	Pressure, kPa - Liquid	Speed of sound, m/s - Liquid
299.79	130.00	911.09
299.80	520.00	913.77
299.81	980.00	916.96
299.81	1500.00	920.51
299.82	1980.00	923.9
299.83	3440.00	933.79
299.85	6010.00	950.89
300.15	10240.00	978.63
299.67	14920.00	1006.82
350.07	120.00	747.75
350.06	530.00	751.64
350.05	960.00	755.62
350.05	1480.00	760.43
350.04	1960.00	764.8
350.04	3530.00	778.49
350.03	6210.00	800.86
350.00	10200.00	832.31
349.98	14970.00	866.97
350.35	22660.00	915.86
349.96	26230.00	939.02
399.71	120.00	600.99
399.70	510.00	605.91
399.70	1030.00	612.25
399.70	1460.00	617.43
399.70	2040.00	624.18
399.68	3610.00	641.86
399.64	6070.00	667.98
399.64	10120.00	706.83
399.63	15100.00	749.46
399.69	19290.00	782.02
399.62	19680.00	784.97
449.64	130.00	461.18
449.64	500.00	467.67
449.63	960.00	475.36
449.70	1490.00	484.22
449.69	1960.00	491.86
449.77	3600.00	516.36
449.87	5900.00	547.45
450.00	10040.00	596.17
450.19	15080.00	646.97
450.23	16420.00	659.13
499.92	330.00	321.35
499.94	520.00	329.04
499.92	1490.00	354.75
499.91	2030.00	367.4
499.88	3480.00	398.42
499.88	6030.00	444.06
500.00	10650.00	509.56
499.93	11150.00	515.95
549.61	3880.00	300.55
549.56	4550.00	317.1
549.55	5070.00	329.01
549.54	5510.00	338.9
549.97	6640.00	364.29
Reference

Correlations

Property	Value	Unit	Temperature (K)	Source
Pvap	[1.33; 202.66]	kPa	[333.88; 477.61]	The Yaws Handbook of Vapor Pressure
Equation			ln(Pvp) = A + B/(T + C)
Coefficient A			1.38745e+01
Coefficient B			-3.32842e+03
Coefficient C			-8.89110e+01
Temperature range, min.			333.88
Temperature range, max.			477.61
Pvap	1.33	kPa	333.88	Calculated Property
Pvap	3.06	kPa	349.85	Calculated Property
Pvap	6.39	kPa	365.82	Calculated Property
Pvap	12.31	kPa	381.79	Calculated Property
Pvap	22.15	kPa	397.76	Calculated Property
Pvap	37.62	kPa	413.73	Calculated Property
Pvap	60.81	kPa	429.70	Calculated Property
Pvap	94.15	kPa	445.67	Calculated Property
Pvap	140.42	kPa	461.64	Calculated Property
Pvap	202.66	kPa	477.61	Calculated Property

Similar Compounds

Find more compounds similar to Cyclotetrasiloxane, octamethyl-.

Mixtures

• Cyclotetrasiloxane, octamethyl- + 1,1,3,3-Tetraphenyl-1,3-dimethyldisiloxane
• 1,3-Diphenyltetramethyldisiloxane + Cyclotetrasiloxane, octamethyl-
• Cyclotetrasiloxane, octamethyl- + Heptane
• Carbon dioxide + Cyclotetrasiloxane, octamethyl-

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
• Ideal-gas heat capacities of dimethylsiloxanes from speed-of-sound measurements and ab initio calculations
• The mixing properties of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl) cyclotrisiloxane with various organosilicon compounds at different temperatures
• Solubilities of 1,3-dimethyl-1,1,3,3-tetraphenyldisiloxane in different solvents from (288.15 to 313.15) K
• Volumetric and refractive properties of the mixtures of 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane with various organosilicon compounds at T = (308.15 to 328.15) K
• Thermodynamic Properties of Octamethylcyclotetrasiloxane
• Selected Physicochemical Properties of Hexamethylcyclotrisiloxane, Octamethylcyclotetrasiloxane, and Decamethylcyclopentasiloxane
• Temperature-Dependent Vapor Pressure of Selected Cyclic and Linear Polydimethylsiloxane Oligomers
• Thermodynamic Study of Heptane + Silicone Mixtures. Excess Volumes and Enthalpies at 298.15 K
• Vapor Liquid Phase Equilibrium Data of CO2 in Some Physical Solvents from 285.19 K to 313.26 K
• NIST Webbook
• The Yaws Handbook of Vapor Pressure

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.