Cyclotetrasiloxane, octamethyl-

Data at NIST subscription sites:

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.


Phase change data

Go To: Top, References, Notes

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

Quantity Value Units Method Reference Comment
Tboil448. to 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
ρc0.995mol/lN/AMcLure and Neville, 1982Uncertainty assigned by TRC = 0.00991 mol/l; Visual, TE, PG; TRC
Quantity Value Units Method Reference Comment
Δvap57.0 ± 0.8kJ/molCVoronkov, Klyuchnikov, et al., 1991AC
Δvap56.1kJ/molIOsthoff and Grubb, 1954Based on data from 303. to 428. K.; AC

Enthalpy of vaporization

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

Antoine Equation Parameters

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

View plot Requires a JavaScript / HTML 5 canvas capable browser.

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

Enthalpy of fusion

ΔfusH (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

Go To: Top, Phase change data, References