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Cyclotetrasiloxane, octamethyl-

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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, Kenneth Kroenlein director
AC - William E. Acree, Jr., James S. Chickos

Quantity Value Units Method Reference Comment
Tboil448. - 449.KN/APCR Inc., 1990BS
Tboil446.2KN/AMyers and Clever, 1969Uncertainty assigned by TRC = 0.6 K; TRC
Quantity Value Units Method Reference Comment
Tfus290.KN/AAlvik and Dale, 1971Uncertainty assigned by TRC = 0.1 K; TRC
Tfus290.65KN/AMarsh, 1968Uncertainty assigned by TRC = 0.2 K; TRC
Tfus287.4KN/AOsthoff, Grubb, et al., 1953Uncertainty assigned by TRC = 0.1 K; TRC
Quantity Value Units Method Reference Comment
Ttriple290.250KN/AMekhtiev and Karasharli, 1981Uncertainty assigned by TRC = 0.02 K; by adiabatic calorimeter; TRC
Ttriple23.760KN/AMekhtiev and Karasharli, 1981Uncertainty assigned by TRC = 0.04 K; by adiabatic calorimeter; TRC
Quantity Value Units Method Reference Comment
Tc585.7KN/AMcLure and Neville, 1982Uncertainty assigned by TRC = 0.3 K; Visual, TE, PG; TRC
Tc586.5KN/AYoung, 1972Uncertainty assigned by TRC = 0.2 K; Visual, TE calib. known Tc of alkanes, PP, sample prep and purification according to K.N.Marsh and R.P.Tomlins, 1970; TRC
Quantity Value Units Method Reference Comment
Pc13.20barN/AMcLure and Neville, 1982Uncertainty assigned by TRC = 0.20 bar; Visual, TE, PG; TRC
Pc13.3959barN/AYoung, 1972Uncertainty assigned by TRC = 0.0686 bar; TRC
Quantity Value Units Method Reference Comment
Vc1.005l/molN/AMcLure and Neville, 1982Uncertainty assigned by TRC = 0.001 l/mol; Visual, TE, PG; TRC
Vc0.984l/molN/AYoung, 1972Uncertainty assigned by TRC = 0.003 l/mol; by method of H.von Eck, Z.Phys. 1939,40,13,; TRC
Quantity Value Units Method Reference Comment
rhoc0.995mol/lN/AMcLure and Neville, 1982Uncertainty assigned by TRC = 0.00991 mol/l; Visual, TE, PG; TRC
Quantity Value Units Method Reference Comment
Deltavap57.0 ± 0.8kJ/molCVoronkov, Klyuchnikov, et al., 1991AC
Deltavap56.1kJ/molIOsthoff and Grubb, 1954Based on data from 303. - 428. K.; AC

Enthalpy of vaporization

DeltavapH (kJ/mol) Temperature (K) Method Reference Comment
47.6376.EBFlaningam, 1986Based on data from 361. - 469. K.; AC
44.1378.N/ADitsent, Skorokhodov, et al., 1971Based on data from 334. - 423. K.; AC
48.5373.IOsthoff and Grubb, 1954Based on data from 303. - 428. K.; AC
45.6398.IOsthoff and Grubb, 1954Based on data from 303. - 428. K.; AC

Antoine Equation Parameters

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

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Temperature (K) A B C Reference Comment
303.6 - 428.54.08301469.89-87.516Osthoff and Grubb, 1954Coefficents calculated by NIST from author's data.

Enthalpy of fusion

DeltafusH (kJ/mol) Temperature (K) Reference Comment
23.77290.5Domalski and Hearing, 1996See also Mekhtiev, Karasharli, et al., 1975 and Alvik, Dale, et al., 1971.; AC

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:


References

Go To: Top, Phase change data, Notes

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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