Cyclotetrasiloxane, octamethyl-

• Formula: C₈H₂₄O₄Si₄
• Molecular weight: 296.6158
• IUPAC Standard InChI: InChI=1S/C8H24O4Si4/c1-13(2)9-14(3,4)11-16(7,8)12-15(5,6)10-13/h1-8H3 Copy

  
• IUPAC Standard InChIKey: HMMGMWAXVFQUOA-UHFFFAOYSA-N Copy
• CAS Registry Number: 556-67-2
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
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• Other names: Oktamethylcyklotetrasiloxan; NUC Silicone VS 7207; CO9810; O9810; Octamethyltetrasiloxane; Octamethylcyclotetrasiloxane; Cyclotetrasilane, octamethyl
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• Information on this page:
  • Phase change data
  • References
  • Notes
• Other data available:
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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Phase change data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Enthalpy of vaporization

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (atm)
    T = temperature (K)

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Enthalpy of fusion

References

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

PCR Inc., 1990
PCR Inc., Research Chemicals Catalog 1990-1991, PCR Inc., Gainesville, FL, 1990, 1. [all data]

Myers and Clever, 1969
Myers, R.S.; Clever, H.L., Surface Tension of Octamethylcyclotetrasiloxane and Hexamethyldisilazane and Their Solutions with Carbon Tetrachloride and n-Hexadecane, J. Chem. Eng. Data, 1969, 14, 161-164. [all data]

Alvik and Dale, 1971
Alvik, T.; Dale, J., On the Lack of Conformational Preferences for Cyclic Dimethylsiloxane Oligomers., Acta Chem. Scand., 1971, 25, 2131, https://doi.org/10.3891/acta.chem.scand.25-2131 . [all data]

Marsh, 1968
Marsh, K.N., Thermodynamics of Octamethylcyclotetrasiloxane mixtures, Trans. Faraday Soc., 1968, 64, 883. [all data]

Osthoff, Grubb, et al., 1953
Osthoff, R.C.; Grubb, W.T.; Burkhard, C.A., Physical Properties of organosilicon compounds. I. Hexamethylcyclotrisiloxane and Octamethylcyclotetrasiloxane, J. Am. Chem. Soc., 1953, 75, 2227-9. [all data]

Mekhtiev and Karasharli, 1981
Mekhtiev, S.A.; Karasharli, K.A., Analysis of the results of thermodynamic studies of a series of organosilicon compounds, Azerb. Khim. Zhur., 1981, (5), 85-88. [all data]

McLure and Neville, 1982
McLure, I.A.; Neville, J.F., The critical temperatures and pressures of hexamethyldisilmethylene, octamethylcyclotetrasiloxane, and decamethylcyclpentasiloxane, J. Chem. Thermodyn., 1982, 14, 385-8. [all data]

Young, 1972
Young, C.L., Equilibrium properties of octamethylcyclotetrasiloxane near its critical point and applicability of the principle of corresponding states, J. Chem. Thermodyn., 1972, 4, 65. [all data]

Voronkov, Klyuchnikov, et al., 1991
Voronkov, M.G.; Klyuchnikov, V.A.; Mironenko, E.V.; Shvets, G.N.; Danilova, T.F.; Khudobin, Yu.I., Thermochemistry of organosilicon compounds, Journal of Organometallic Chemistry, 1991, 406, 1-2, 91-97, https://doi.org/10.1016/0022-328X(91)83174-3 . [all data]

Osthoff and Grubb, 1954
Osthoff, Robert C.; Grubb, W.T., Physical Properties of Organosilicon Compounds. III. Thermodynamic Properties of Octamethylcyclotetrasiloxane, J. Am. Chem. Soc., 1954, 76, 2, 399-401, https://doi.org/10.1021/ja01631a025 . [all data]

Flaningam, 1986
Flaningam, Ora L., Vapor pressures of poly(dimethylsiloxane) oligomers, J. Chem. Eng. Data, 1986, 31, 3, 266-272, https://doi.org/10.1021/je00045a002 . [all data]

Ditsent, Skorokhodov, et al., 1971
Ditsent, V.E.; Skorokhodov, I.I.; Terent'eva, N.A.; Zolotareva, M.N., Russ. J. Phys. Chem., 1971, 45, 6, 901. [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [all data]

Mekhtiev, Karasharli, et al., 1975
Mekhtiev, S.A.; Karasharli, K.A.; Dzhafarov, O.I., The true heat capacity of 1,1,3,3,5,5-hexamethyl-7,7-diphenylcyclotetrasiloxane in the temperature range 13 to 320 K, Zhur. Fiz. Khim., 1975, 49, 259. [all data]

Alvik, Dale, et al., 1971
Alvik, Thor; Dale, Johannes; Fernholt, L.; Hedberg, Kenneth; Schaumburg, Kjeld; Ehrenberg, L., On the Lack of Conformational Preferences for Cyclic Dimethylsiloxane Oligomers., Acta Chem. Scand., 1971, 25, 2131-2141, https://doi.org/10.3891/acta.chem.scand.25-2131 . [all data]

Notes

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• Symbols used in this document:
  

  Pc	Critical pressure
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Vc	Critical volume
  ΔfusH	Enthalpy of fusion
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions
  ρc	Critical density

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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