Pentane, 3-ethyl-3-methyl-

Formula: C₈H₁₈
Molecular weight: 114.2285
IUPAC Standard InChI: InChI=1S/C8H18/c1-5-8(4,6-2)7-3/h5-7H2,1-4H3
IUPAC Standard InChIKey: GIEZWIDCIFCQPS-UHFFFAOYSA-N
CAS Registry Number: 1067-08-9
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript.
Other names: 3-Ethyl-3-methylpentane; 3-Methyl-3-ethylpentane
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Gas phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-215.0 ± 1.3	kJ/mol	Ccb	Prosen and Rossini, 1945	ALS

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
127.99	200.	Scott D.W., 1974	Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, 2, Scott D.W., 1974]. This approach gives a good agreement with experimental data available for alkanes. However, large uncertainties could be expected at high temperatures.; GT
173.30	273.15
188.0 ± 1.9	298.15
189.07	300.
244.60	400.
293.21	500.
334.72	600.
370.28	700.
400.83	800.
427.19	900.
450.20	1000.
470.28	1100.
487.85	1200.
502.08	1300.
518.82	1400.
531.37	1500.

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
247.27	403.3	Barrow G.M., 1951	GT
275.73	462.6
303.76	521.7

Reaction thermochemistry data

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Data compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

= Pentane, 3-ethyl-3-methyl-

By formula: C₈H₁₈ = C₈H₁₈

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-3.1 ± 0.88	kJ/mol	Ciso	Prosen and Rossini, 1945, 2	liquid phase; Calculated from ΔHc

Gas Chromatography

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Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Kovats' RI, non-polar column, isothermal

View large format table.

Column type	Active phase	Temperature (C)	I	Reference	Comment
Capillary	OV-101	0.	765.	Skrbic, 1997
Capillary	Squalane	25.	769.	Hilal, Carreira, et al., 1994
Capillary	OV-1	60.	772.	Engewald, Maurer, et al., 1989
Capillary	Squalane	50.	773.8	Lunskii and Paizanskaya, 1988	He; Column length: 50. m; Column diameter: 0.22 mm
Capillary	Squalane	70.	776.9	Lunskii and Paizanskaya, 1988	He; Column length: 50. m; Column diameter: 0.22 mm
Capillary	OV-101	40.	768.4	Boneva and Dimov, 1986	100. m/0.27 mm/0.9 μm
Capillary	OV-101	50.	769.3	Boneva and Dimov, 1986	100. m/0.27 mm/0.9 μm
Capillary	OV-101	60.	770.2	Boneva and Dimov, 1986	100. m/0.27 mm/0.9 μm
Capillary	OV-101	70.	771.2	Boneva and Dimov, 1986	100. m/0.27 mm/0.9 μm
Capillary	DB-1	60.	772.	Lubeck and Sutton, 1983	Column length: 60. m; Column diameter: 0.264 mm
Capillary	DB-1	60.	772.2	Lubeck and Sutton, 1983	60. m/0.259 mm/1. μm
Capillary	OV-101	50.	769.	Johansen and Ettre, 1982	100. m/0.27 mm/0.20 μm
Capillary	OV-101	50.	769.	Johansen and Ettre, 1982	55. m/0.27 mm/0.9 μm
Capillary	SF-96	50.	769.	Johansen and Ettre, 1982	91.4 m/0.31 mm/0.20 μm
Packed	Triacontane	80.	780.	Castello and D'Amato, 1979	He, Chromosorb W AW (60-80 mesh); Column length: 3. m
Packed	Squalane	80.	780.	Castello and D'Amato, 1979	He, Chromosorb W AW (60-80 mesh); Column length: 3. m
Capillary	Squalane	70.	778.6	Nabivach and Kirilenko, 1979	N2; Column length: 50. m
Capillary	Squalane	60.	776.	Chretien and Dubois, 1976
Capillary	Squalane	50.	774.	Rijks and Cramers, 1974	N2; Column length: 100. m; Column diameter: 0.25 mm
Capillary	Squalane	70.	778.	Rijks and Cramers, 1974	N2; Column length: 100. m; Column diameter: 0.25 mm
Capillary	Squalane	70.	774.1	Dimov and Schopov, 1971	Column length: 100. m; Column diameter: 0.25 mm
Packed	SE-30	80.	781.	Mitra and Saha, 1970	N2
Packed	Squalane	25.	769.	Mitra and Saha, 1970	N2
Packed	Squalane	80.	780.	Mitra and Saha, 1970	N2
Capillary	Squalane	40.	772.	Matukuma, 1969	N2; Column length: 91.4 m; Column diameter: 0.25 mm
Packed	Squalane	27.	769.	Hively and Hinton, 1968	He, Chromosorb P; Column length: 15. m; Column diameter: 0.25 mm
Packed	Squalane	49.	774.	Hively and Hinton, 1968	He, Chromosorb P; Column length: 15. m; Column diameter: 0.25 mm
Packed	Squalane	67.	777.	Hively and Hinton, 1968	He, Chromosorb P; Column length: 15. m; Column diameter: 0.25 mm
Packed	Squalane	86.	781.	Hively and Hinton, 1968	He, Chromosorb P; Column length: 15. m; Column diameter: 0.25 mm
Capillary	Squalane	30.	770.	Tourres, 1967	H2; Column length: 100. m; Column diameter: 0.25 mm
Capillary	Squalane	50.	774.	Tourres, 1967	H2; Column length: 100. m; Column diameter: 0.25 mm
Capillary	Squalane	70.	778.	Tourres, 1967	H2; Column length: 100. m; Column diameter: 0.25 mm
Packed	Squalane	40.	772.	Evans, 1966	Untreated celite; Column length: 1.8 m
Packed	Squalane	55.	775.	Evans, 1966	Untreated celite; Column length: 1.8 m
Packed	Squalane	70.	778.	Evans, 1966	Untreated celite; Column length: 1.8 m

Kovats' RI, non-polar column, temperature ramp

View large format table.

Column type	Active phase	I	Reference	Comment
Capillary	OV-101	764.	Hayes and Pitzer, 1982	110. m/0.25 mm/0.20 μm, He, 1. K/min; T_start: 35. C; T_end: 200. C

Kovats' RI, non-polar column, custom temperature program

View large format table.

Column type	Active phase	I	Reference	Comment
Capillary	Petrocol DH-100	766.5	Haagen-Smit Laboratory, 1997	He; Column length: 100. m; Column diameter: 0.2 mm; Program: 5C(10min) => 5C/min => 50C(48min) => 1.5C/min => 195C(91min)

Van Den Dool and Kratz RI, non-polar column, temperature ramp

View large format table.

Column type	Active phase	I	Reference	Comment
Capillary	Petrocol DH	768.4	Censullo, Jones, et al., 2003	50. m/0.25 mm/0.5 μm, He, 35. C @ 10. min, 3. K/min, 200. C @ 10. min
Capillary	Petrocol DH	765.42	Subramaniam, Bochniak, et al., 1994	100. m/0.25 mm/0.5 μm, He, 1. K/min; T_start: 30. C; T_end: 220. C
Capillary	Petrocol DH	766.	White, Hackett, et al., 1992	100. m/0.25 mm/0.5 μm, He, 1. K/min; T_start: 30. C; T_end: 220. C
Capillary	Ultra-1	763.06	Haynes and Pitzer, 1985	50. m/0.22 mm/0.33 μm, He, 1. K/min; T_start: -30. C; T_end: 240. C
Capillary	Ultra-1	765.47	Haynes and Pitzer, 1985	50. m/0.22 mm/0.33 μm, He, 2. K/min; T_start: -30. C; T_end: 240. C
Capillary	Ultra-1	766.94	Haynes and Pitzer, 1985	50. m/0.22 mm/0.33 μm, He, 3. K/min; T_start: -30. C; T_end: 240. C
Capillary	Ultra-2	764.38	Haynes and Pitzer, 1985	50. m/0.22 mm/0.33 μm, He, 1. K/min; T_start: -30. C; T_end: 240. C
Capillary	Ultra-2	766.76	Haynes and Pitzer, 1985	50. m/0.22 mm/0.33 μm, He, 2. K/min; T_start: -30. C; T_end: 240. C
Capillary	Ultra-2	768.22	Haynes and Pitzer, 1985	50. m/0.22 mm/0.33 μm, He, 3. K/min; T_start: -30. C; T_end: 240. C
Capillary	OV-101	764.	Hayes and Pitzer, 1981	108. m/0.25 mm/0.2 μm, 1. K/min; T_start: 35. C; T_end: 200. C

Normal alkane RI, non-polar column, isothermal

View large format table.

Column type	Active phase	Temperature (C)	I	Reference	Comment
Capillary	Methyl Silicone	50.	774.	N/A	N2; Column length: 74.6 m; Column diameter: 0.28 mm
Capillary	Squalane	100.	783.	Dimov N., 1976
Capillary	Squalane	70.	778.	Dimov N., 1976
Capillary	Squalane	86.	773.	Vigdergauz and Martynov, 1971	He; Column length: 150. m; Column diameter: 0.35 mm

Normal alkane RI, non-polar column, temperature ramp

View large format table.

Column type	Active phase	I	Reference	Comment
Capillary	Polydimethyl siloxane: CP-Sil 5 CB	770.	Bramston-Cook, 2013	60. m/0.25 mm/1.0 μm, Helium, 45. C @ 1.45 min, 3.6 K/min, 210. C @ 2.72 min
Capillary	Petrocol DH	768.	Supelco, 2012	100. m/0.25 mm/0.50 μm, Helium, 20. C @ 15. min, 15. K/min, 220. C @ 30. min
Capillary	OV-101	770.	Orav, Kailas, et al., 1999	50. m/0.20 mm/0.50 μm, Helium, 30. C @ 6. min, 1. K/min; T_end: 100. C

Normal alkane RI, non-polar column, custom temperature program

View large format table.

Column type	Active phase	I	Reference	Comment
Capillary	Methyl Silicone	781.	Chen and Feng, 2007	Program: not specified
Capillary	Methyl Silicone	774.	Feng and Mu, 2007	Program: not specified
Capillary	OV-101	776.	Du and Liang, 2003	Program: not specified
Capillary	Methyl Silicone	766.	Spieksma, 1999	Program: not specified
Capillary	OV-101	765.	Skrbic and Cvejanov, 1993	Program: not specified
Capillary	OV-1, SE-30, Methyl silicone, SP-2100, OV-101, DB-1, etc.	764.	Waggott and Davies, 1984	Hydrogen; Column length: 50. m; Column diameter: 0.32 mm; Program: not specified

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas Chromatography, Notes

Prosen and Rossini, 1945
Prosen, E.J.; Rossini, F.D., Heats of combustion and formation of the paraffin hydrocarbons at 25° C, J. Res. NBS, 1945, 263-267. [all data]

Scott D.W., 1974
Scott D.W., Chemical Thermodynamic Properties of Hydrocarbons and Related Substances. Properties of the Alkane Hydrocarbons, C1 through C10 in the Ideal Gas State from 0 to 1500 K. U.S. Bureau of Mines, Bulletin 666, 1974. [all data]

Scott D.W., 1974, 2
Scott D.W., Correlation of the chemical thermodynamic properties of alkane hydrocarbons, J. Chem. Phys., 1974, 60, 3144-3165. [all data]

Barrow G.M., 1951
Barrow G.M., Experimental vapor heat capacities and heats of vaporization of seven octanes, J. Am. Chem. Soc., 1951, 73, 1824-1826. [all data]

Prosen and Rossini, 1945, 2
Prosen, E.J.; Rossini, F.D., Heats of isomerization of the 18 octanes, J. Res. NBS, 1945, 34, 163-174. [all data]

Skrbic, 1997
Skrbic, B.D., Unified retention concept -- statistical treatment of Kováts retention index, J. Chromatogr. A, 1997, 764, 2, 257-264, https://doi.org/10.1016/S0021-9673(96)00955-7 . [all data]

Hilal, Carreira, et al., 1994
Hilal, S.H.; Carreira, L.A.; Karickhoff, S.W.; Melton, C.M., Estimation of Gas-Liquid Chromatographic Retention Times from Molecular Structure, J. Chromatogr. A, 1994, 662, 2, 269-280, https://doi.org/10.1016/0021-9673(94)80515-6 . [all data]

Engewald, Maurer, et al., 1989
Engewald, W.; Maurer, T.; Schiefke, A., Investigation of isomeric hydrocarbons by gas-solid chromatography on graphitized thermal carbon black, Pure Appl. Chem., 1989, 61, 11, 2001-2004, https://doi.org/10.1351/pac198961112001 . [all data]

Lunskii and Paizanskaya, 1988
Lunskii, M.Kh.; Paizanskaya, I.L., Identification of hydrocarbons C₁-C₉ of petrol fractions of oils and condensates in the use of capillary columns with dinonylphthalate, Zh. Anal. Khim., 1988, 43, 127-135. [all data]

Boneva and Dimov, 1986
Boneva, S.; Dimov, N., Unified retention index of hydrocarbons separated on dimethylsilicone OV-101, Chromatographia, 1986, 21, 12, 697-700, https://doi.org/10.1007/BF02313682 . [all data]

Lubeck and Sutton, 1983
Lubeck, A.J.; Sutton, DL., Kovats retention indices of selected hydrocarbons through C₁₀ on bonded phase fused silica capillaries, J. Hi. Res. Chromatogr. Chromatogr. Comm., 1983, 6, 6, 328-332, https://doi.org/10.1002/jhrc.1240060612 . [all data]

Johansen and Ettre, 1982
Johansen, N.G.; Ettre, L.S., Retention index values of hydrocarbons on open-tubular columns coated with methylsilicone liquid phases, Chromatographia, 1982, 15, 10, 625-630, https://doi.org/10.1007/BF02279488 . [all data]

Castello and D'Amato, 1979
Castello, G.; D'Amato, G., Use of Linear and Branched-Chain Paraffinic Liquid Phases as Non-Polar Reference Materials in Gas Chromatography, J. Chromatogr., 1979, 175, 1, 27-35, https://doi.org/10.1016/S0021-9673(00)86400-6 . [all data]

Nabivach and Kirilenko, 1979
Nabivach, V.M.; Kirilenko, A.V., The use of retention indices for identifying the components of crude benzene, Solid Fuel Chem. (Engl. Transl.), 1979, 13, 3, 82-87. [all data]

Chretien and Dubois, 1976
Chretien, J.R.; Dubois, J.-E., New Perspectives in the Prediction of Kovats Indices, J. Chromatogr., 1976, 126, 171-189, https://doi.org/10.1016/S0021-9673(01)84071-1 . [all data]

Rijks and Cramers, 1974
Rijks, J.A.; Cramers, C.A., High precision capillary gas chromatography of hydrocarbons, Chromatographia, 1974, 7, 3, 99-106, https://doi.org/10.1007/BF02269819 . [all data]

Dimov and Schopov, 1971
Dimov, N.; Schopov, D., Empirische korrektion der physikalisch-chemischen retentionsindexe von kohlenwasserstoffen auf squalan, J. Chromatogr., 1971, 63, 223-228, https://doi.org/10.1016/S0021-9673(01)85634-X . [all data]

Mitra and Saha, 1970
Mitra, G.D.; Saha, N.C., Determination of Retention Indices of Saturated Hydrocarbons by Graphical Methods, J. Chromatogr. Sci., 1970, 8, 2, 95-102, https://doi.org/10.1093/chromsci/8.2.95 . [all data]

Matukuma, 1969
Matukuma, A., Retention indices of alkanes through C₁₀ and alkenes through C₈ and relation between boiling points and retention data, Gas Chromatogr., Int. Symp. Anal. Instrum. Div Instrum Soc. Amer., 1969, 7, 55-75. [all data]

Hively and Hinton, 1968
Hively, R.A.; Hinton, R.E., Variation of the retention index with temperature on squalane substrates, J. Gas Chromatogr., 1968, 6, 4, 203-217, https://doi.org/10.1093/chromsci/6.4.203 . [all data]

Tourres, 1967
Tourres, D.A., Structure moléculaire et rétention en chromatographie en phase gazeuse. Influence de la température sur l'indice de rétention d'alcanes isomères, J. Chromatogr., 1967, 30, 357-377, https://doi.org/10.1016/S0021-9673(00)84168-0 . [all data]

Evans, 1966
Evans, M.B., Retention indices of solutes on squalane, dinonyl phthalate, and polyethylene glycol 400, J. Gas Chromatogr., 1966, 4, 1, 1-3, https://doi.org/10.1093/chromsci/4.1.1 . [all data]

Hayes and Pitzer, 1982
Hayes, P.C., Jr.; Pitzer, E.W., Characterizing petroleum- and shale-derived jet fuel distillates via temperature-programmed Kováts indices, J. Chromatogr., 1982, 253, 179-198, https://doi.org/10.1016/S0021-9673(01)88376-X . [all data]

Haagen-Smit Laboratory, 1997
Haagen-Smit Laboratory, Procedure for the detailed hydrocarbon analysis of gasolines by single column high efficiency (capillary) column gas chromatography, SOP NO. MLD 118, Revision No. 1.1, California Environmental Protection Agency, Air Resources Board, El Monte, California, 1997, 22. [all data]

Censullo, Jones, et al., 2003
Censullo, A.C.; Jones, D.R.; Wills, M.T., Speciation of the volatile organic compounds (VOCs) in solventborne aerosol coatings by solid phase microextraction-gas chromatography, J. Coat. Technol., 2003, 75, 936, 47-53, https://doi.org/10.1007/BF02697922 . [all data]

Subramaniam, Bochniak, et al., 1994
Subramaniam, B.; Bochniak, D.; Snavely, K., Fischer-Tropsch synthesis in supercritical reaction media, Lawrence Department of Chemical and Petroleum Engineering (DOE/PC/92532--T7), United States Department of Energy, Pittsburgh, PA, 1994, 8, retrieved from http://www.NTIS.gov. [all data]

White, Hackett, et al., 1992
White, C.M.; Hackett, J.; Anderson, R.R.; Kail, S.; Spock, P.S., Linear temperature programmed retention indices of gasoline range hydrocarbons and chlorinated hydrocarbons on cross-linked polydimethylsiloxane, J. Hi. Res. Chromatogr., 1992, 15, 2, 105-120, https://doi.org/10.1002/jhrc.1240150211 . [all data]

Haynes and Pitzer, 1985
Haynes, P.C., Jr.; Pitzer, E.W., Disengaging solutes in shale- and petroleum-derived jet fuels by altering GC programmed temperature rates, J. Hi. Res. Chromatogr. Chromatogr. Comm., 1985, 8, 5, 230-242, https://doi.org/10.1002/jhrc.1240080504 . [all data]

Hayes and Pitzer, 1981
Hayes, P.C., Jr.; Pitzer, E.W., Kovats indices as a tool in characterizing hydrocarbon fuels in temperature programmed glass capillary gas chromatography. Part 1. Qualitative identification, Inhouse rpt. for Air Force Wright Aeronautical Labs., Air Force Wright Aeronautical Labs., Wright-Patterson AFB, Ohio, 1981, 75. [all data]

Dimov N., 1976
Dimov N., Quantitative gas chromatographic analysis and determination of solute properties. An exact equation for the calculation of the retention indices of isoalkanes on Squalane, J. Chromatogr., 1976, 119, 109-118, https://doi.org/10.1016/S0021-9673(00)86775-8 . [all data]

Vigdergauz and Martynov, 1971
Vigdergauz, M.S.; Martynov, A.A., Some applications of the gas chromatographic linear retention indices, Chromatographia, 1971, 4, 10, 463-467, https://doi.org/10.1007/BF02268816 . [all data]

Bramston-Cook, 2013
Bramston-Cook, R., Kovats indices for C2-C13 hydrocarbons and selected oxygenated/halocarbons with 100 % dimethylpolysiloxane columns, 2013, retrieved from http://lotusinstruments.com/monographs/List .... [all data]

Supelco, 2012
Supelco, CatalogNo. 24160-U, Petrocol DH Columns. Catalog No. 24160-U, 2012, retrieved from http://www.sigmaaldrich.com/etc/medialib/docs/Supelco/Datasheet/1/w97949.Par.0001.File.tmp/w97949.pdf. [all data]

Orav, Kailas, et al., 1999
Orav, A.; Kailas, T.; Muurisepp, M.; Kann, J., Composition of the oil from waste tires. 1. Fraction boiling at yp to 160 0C, Proc. Estonian Acad. Sci. Chem., 1999, 48, 1, 30-39. [all data]

Chen and Feng, 2007
Chen, Y.; Feng, C., QSPR study on gas chromatography retention index of some organic pollutants, Comput. Appl. Chem. (China), 2007, 24, 10, 1404-1408. [all data]

Feng and Mu, 2007
Feng, H.; Mu, L.-L., Quantitative structure-retention relationships for alkane and its derivatives based on electrotopological state index and molecular shape index, Chem. Ind. Engineering (Chinese), 2007, 24, 2, 161-168. [all data]

Du and Liang, 2003
Du, Y.; Liang, Y., Data mining for seeking accurate quantitative relationship between molecular structure and GC retention indices of alkanes by projection pursuit, Comput. Biol. Chem., 2003, 27, 3, 339-353, https://doi.org/10.1016/S1476-9271(02)00081-6 . [all data]

Spieksma, 1999
Spieksma, W., Determination of vapor liquid equilibrium from the Kovats retention index on dimethylsilicone using the Wilson mixing tool, J. Hi. Res. Chromatogr., 1999, 22, 10, 565-588, https://doi.org/10.1002/(SICI)1521-4168(19991001)22:10<565::AID-JHRC565>3.0.CO;2-2 . [all data]

Skrbic and Cvejanov, 1993
Skrbic, B.D.; Cvejanov, J.Dj., Correlation of unified retention indices for OV-101 and squalane, Chromatographia, 1993, 35, 1/2, 109-110, https://doi.org/10.1007/BF02278566 . [all data]

Waggott and Davies, 1984
Waggott, A.; Davies, I.W., Identification of organic pollutants using linear temperature programmed retention indices (LTPRIs) - Part II, 1984, retrieved from http://dwi.defra.gov.uk/research/completed-research/reports/dwi0383.pdf. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas Chromatography, References

Symbols used in this document:

C_p,gas Constant pressure heat capacity of gas

Δ_fH°_gas Enthalpy of formation of gas at standard conditions

Δ_rH° Enthalpy of reaction at standard conditions
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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C_p,gas	Constant pressure heat capacity of gas
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions