Cyclotrisiloxane, hexamethyl-

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Condensed phase thermochemistry 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 by: Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
solid,1 bar412.1J/mol*KN/AKuliev, Dzhafarov, et al., 1982 

Constant pressure heat capacity of solid

Cp,solid (J/mol*K) Temperature (K) Reference Comment
360.0298.15Kuliev, Dzhafarov, et al., 1982T = 4.2 to 370 K. Data given graphically except for data at 298.15 K.

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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Tboil407.KN/APCR Inc., 1990BS
Quantity Value Units Method Reference Comment
Tfus337.KN/AAlvik and Dale, 1971Uncertainty assigned by TRC = 0.1 K; TRC
Tfus339.5KN/AOsthoff, Grubb, et al., 1953Uncertainty assigned by TRC = 0.1 K; TRC
Quantity Value Units Method Reference Comment
Ttriple335.22KN/AKuliev, Dzhafarov, et al., 1982, 2Uncertainty assigned by TRC = 0.02 K; TRC

Enthalpy of vaporization

ΔvapH (kJ/mol) Temperature (K) Method Reference Comment
40.8357.EBFlaningam, 1986Based on data from 342. to 419. K.; AC
39.7368.N/ABragin and Karapet'yants, 1974Based on data from 353. to 403. K.; AC
39.373.N/ADitsent, Skorokhodov, et al., 1971Based on data from 339. to 407. K.; AC
39.7365.N/AOsthoff, Grubb, et al., 1953, 2Based on data from 343. to 388. 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
297.4 to 335.61.75483404.805-196.763Osthoff, Grubb, et al., 1953, 2Coefficents calculated by NIST from author's data.

Enthalpy of sublimation

ΔsubH (kJ/mol) Temperature (K) Reference Comment
55.2 ± 0.4316.Osthoff, Grubb, et al., 1953, 2Based on data from 297. to 335. K.; AC

Enthalpy of fusion

ΔfusH (kJ/mol) Temperature (K) Reference Comment
16.61335.2Domalski and Hearing, 1996See also Alvik, Dale, et al., 1971.; AC

Enthalpy of phase transition

ΔHtrs (kJ/mol) Temperature (K) Initial Phase Final Phase Reference Comment
16.611335.22crystaline, IliquidKuliev, Dzhafarov, et al., 1982DH

Entropy of phase transition

ΔStrs (J/mol*K) Temperature (K) Initial Phase Final Phase Reference Comment
49.5335.22crystaline, IliquidKuliev, Dzhafarov, et al., 1982DH

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

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

Kuliev, Dzhafarov, et al., 1982
Kuliev, A.M.; Dzhafarov, O.I.; Karasharli, K.A.; Kostryukov, V.N., Heat capacity and thermodynamic functions of cyclic methylphenylsiloxanes, Zhur. Fiz. Khim., 1982, 56, 310-313. [all data]

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

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]

Kuliev, Dzhafarov, et al., 1982, 2
Kuliev, A.M.; Dzhafarov, O.I.; Karasharli, K.A.; Kostryukov, V.N., Heat capacity and thermodynamic functions of cyclic methylphenylsiloxanes, Zh. Fiz. Khim., 1982, 56, 310-13. [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]

Bragin and Karapet'yants, 1974
Bragin, G.P.; Karapet'yants, M.K., Russ. J. Phys. Chem., 1974, 48, 612. [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]

Osthoff, Grubb, et al., 1953, 2
Osthoff, Robert C.; Grubb, W.T.; Burkhard, Charles A., Physical Properties of Organosilicon Compounds. I. Hexamethylcyclotrisiloxane and Octamethylcyclotetrasiloxane, J. Am. Chem. Soc., 1953, 75, 9, 2227-2229, https://doi.org/10.1021/ja01105a060 . [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]

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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