1-Propanol, 2-methyl-

Formula: C₄H₁₀O
Molecular weight: 74.1216
IUPAC Standard InChI: InChI=1S/C4H10O/c1-4(2)3-5/h4-5H,3H2,1-2H3
IUPAC Standard InChIKey: ZXEKIIBDNHEJCQ-UHFFFAOYSA-N
CAS Registry Number: 78-83-1
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: Isobutyl alcohol; Isobutanol; Isopropylcarbinol; 2-Methyl-1-propanol; iso-C4H9OH; Fermentation butyl alcohol; 1-Hydroxymethylpropane; 2-Methylpropanol; 2-Methylpropan-1-ol; 2-Methylpropanol-1; 2-Methylpropyl alcohol; Butanol-iso; Alcool isobutylique; Isobutylalkohol; Rcra waste number U140; UN 1212; i-Butyl alcohol; Isopropyl carbitol; Propanol, 2-methyl-; 2-methyl-1-propanyl alcohol; i-Butanol; Methyl-2 propanol-1; NSC 5708; 2-methylpropanoI
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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
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-67.8 ± 0.2	kcal/mol	Eqk	Connett, 1975	Heat of dehydrogenation; ALS
Δ_fH°_gas	-67.61	kcal/mol	N/A	Chao and Rossini, 1965	Value computed using Δ_fH_liquid° value of -333.6±0.6 kj/mol from Chao and Rossini, 1965 and Δ_vapH° value of 50.7 kj/mol from Skinner and Snelson, 1960.; DRB
Δ_fH°_gas	-67.9 ± 0.35	kcal/mol	Ccb	Skinner and Snelson, 1960	ALS
Quantity	Value	Units	Method	Reference	Comment
S°_gas	83.65	cal/mol*K	N/A	Counsell J.F., 1968	GT

Constant pressure heat capacity of gas

C_p,gas (cal/mol*K)	Temperature (K)	Reference	Comment
31.965	379.99	Stromsoe E., 1970	Ideal gas heat capacities are given by [ Stromsoe E., 1970] as a linear function Cp=f1(a+bT). This expression approximates the experimental values with the average deviation of 0.71 J/molK. The accuracy of the experimental heat capacities [ Stromsoe E., 1970] is estimated as less than 0.3%. Please also see Counsell J.F., 1970.; GT
32.108	381.23
33.48 ± 0.17	390.55
33.88 ± 0.17	397.65
33.353	400.03
34.40 ± 0.17	406.95
34.95 ± 0.17	416.95
35.35 ± 0.17	424.05
34.978	425.01
36.34 ± 0.17	441.85
36.561	450.06
36.86 ± 0.17	451.25
38.15 ± 0.17	474.35
37.988	475.09
38.34 ± 0.17	477.75
39.67 ± 0.17	501.55
41.02 ± 0.17	525.85
42.16 ± 0.17	546.35
44.20 ± 0.17	582.95
45.29 ± 0.17	602.55

Condensed phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_liquid	-80.0 ± 0.2	kcal/mol	Eqk	Connett, 1975	Heat of dehydrogenation; ALS
Δ_fH°_liquid	-79.73 ± 0.15	kcal/mol	Ccb	Chao and Rossini, 1965	see Rossini, 1934; ALS
Δ_fH°_liquid	-80.00 ± 0.20	kcal/mol	Ccb	Skinner and Snelson, 1960	ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-638.06 ± 0.14	kcal/mol	Ccb	Chao and Rossini, 1965	see Rossini, 1934; Corresponding Δ_fHº_liquid = -79.72 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-637.79 ± 0.20	kcal/mol	Ccb	Skinner and Snelson, 1960	Corresponding Δ_fHº_liquid = -79.99 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-637.139	kcal/mol	Ccb	Richards and Davis, 1920	At 291 K; Corresponding Δ_fHº_liquid = -80.641 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	51.27	cal/mol*K	N/A	Counsell, Lees, et al., 1968	DH
Quantity	Value	Units	Method	Reference	Comment
S°_{solid,1 bar}	33.63	cal/mol*K	N/A	Counsell, Lees, et al., 1968	glass phase; DH

Constant pressure heat capacity of liquid

C_p,liquid (cal/mol*K)	Temperature (K)	Reference	Comment
43.272	298.15	Okano, Ogawa, et al., 1988	DH
43.501	298.15	Piekarski and Somsen, 1988	DH
44.36	303.15	Rybalkin, Emel'yanov, et al., 1978	T = 293.15 to 353.15 K. Cp given as 2504 J/kg*K.; DH
44.31	301.2	Paz Andrade, Paz, et al., 1970	T = 28, 40°C.; DH
43.26	298.15	Counsell, Lees, et al., 1968	T = 10 to 350 K.; DH
48.11	323.	Swietoslawski and Zielenkiewicz, 1960	Mean value 21 to 78°C.; DH
51.41	333.	Swietoslawski and Zielenkiewicz, 1958	Mean value 21 to 99°C.; DH
44.00	298.1	Zhdanov, 1941	T = 5 to 46°C.; DH
44.69	303.	Willams and Daniels, 1924	T = 303 to 343 K. Equation only.; DH

Constant pressure heat capacity of solid

C_p,solid (cal/mol*K)	Temperature (K)	Reference	Comment
30.88	180.	Counsell, Lees, et al., 1968	glass phase; T = 10 to 180 K.; DH

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References, Notes

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	10.02 ± 0.02	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	189.7	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	182.2	kcal/mol	N/A	Hunter and Lias, 1998	HL

Ionization energy determinations

IE (eV)	Method	Reference	Comment
10.02 ± 0.05	PIPECO	Shao, Baer, et al., 1988	LL
10.11 ± 0.07	EI	Bowen and Maccoll, 1984	LBLHLM
10.12 ± 0.04	EI	Holmes, Fingas, et al., 1981	LLK
10.09 ± 0.02	PE	Cocksey, Eland, et al., 1971	LLK
10.47 ± 0.03	PE	Peel and Willett, 1975	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
CH₅O⁺	10.43 ± 0.03	C₃H₅	PIPECO	Shao, Baer, et al., 1988	LL
CH₅O⁺	10.54 ± 0.05	CH₂CHCH₂	EI	Holmes and Lossing, 1984	LBLHLM
C₃H₆⁺	11.00 ± 0.03	CH₃OH	PIPECO	Shao, Baer, et al., 1988	LL
C₃H₇⁺	11.28 ± 0.05	CH₂OH	PIPECO	Shao, Baer, et al., 1988	LL
C₄H₈⁺	10.33 ± 0.03	H₂O	PIPECO	Shao, Baer, et al., 1988	LL

De-protonation reactions

C₄H₉O^- + = 1-Propanol, 2-methyl-

By formula: C₄H₉O^- + H⁺ = C₄H₁₀O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	374.5 ± 2.0	kcal/mol	CIDC	Haas and Harrison, 1993	gas phase; Both metastable and 50 eV collision energy.; B
Δ_rH°	374.7 ± 2.1	kcal/mol	G+TS	Bartmess, Scott, et al., 1979	gas phase; value altered from reference due to change in acidity scale; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	367.9 ± 2.1	kcal/mol	H-TS	Haas and Harrison, 1993	gas phase; Both metastable and 50 eV collision energy.; B
Δ_rG°	368.1 ± 2.0	kcal/mol	IMRE	Bartmess, Scott, et al., 1979	gas phase; value altered from reference due to change in acidity scale; B

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, Notes

Connett, 1975
Connett, J.E., Chemical equilibria 6. Measurement of equilibrium constants for the dehydrogenation of 2-methylpropan-1-ol by a vapour-flow technique, J. Chem. Thermodyn., 1975, 7, 1159-1162. [all data]

Chao and Rossini, 1965
Chao, J.; Rossini, F.D., Heats of combustion, formation, and isomerization of nineteen alkanols, J. Chem. Eng. Data, 1965, 10, 374-379. [all data]

Skinner and Snelson, 1960
Skinner, H.A.; Snelson, A., The heats of combustion of the four isomeric butyl alcohols, Trans. Faraday Soc., 1960, 56, 1776-1783. [all data]

Counsell J.F., 1968
Counsell J.F., Thermodynamic properties of organic oxygen compounds. Part XIX. Low-temperature heat capacity and entropy of propan-1-ol, 2-methylpropan-1-ol, and pentan-1-ol, J. Chem. Soc. A, 1968, 1819-1823. [all data]

Stromsoe E., 1970
Stromsoe E., Heat capacity of alcohol vapors at atmospheric pressure, J. Chem. Eng. Data, 1970, 15, 286-290. [all data]

Counsell J.F., 1970
Counsell J.F., Thermodynamic properties of organic oxygen compounds. 24. Vapor heat capacities and enthalpies of vaporization of ethanol, 2-methyl-1-propanol, and 1-pentanol, J. Chem. Thermodyn., 1970, 2, 367-372. [all data]

Rossini, 1934
Rossini, F.D., Heats of combustion and of formation of the normal aliphatic alcohols in the gaseous and liquid states, and the energies of their atomic linkages, J. Res. NBS, 1934, 13, 189-197. [all data]

Richards and Davis, 1920
Richards, T.W.; Davis, H.S., The heats of combustion of benzene, toluene, aliphatic alcohols, cyclohexanol, and other carbon compounds, J. Am. Chem. Soc., 1920, 42, 1599-1617. [all data]

Counsell, Lees, et al., 1968
Counsell, J.F.; Lees, E.B.; Martin, J.F., Thermodynamic properties of organic oxygen compounds. Part XIX. Low temperature heat capacity and entropy of propan-1-ol, 2-methyl-propan-1-ol, and pentan-1-ol, 1968, J. [all data]

Okano, Ogawa, et al., 1988
Okano, T.; Ogawa, H.; Murakami, S., Molar excess volumes, isentropic compressions, and isobaric heat capacities of methanol-isomeric butanol systems at 298.15 K, Can. J. Chem., 1988, 66, 713-717. [all data]

Piekarski and Somsen, 1988
Piekarski, H.; Somsen, G., Heat capacities and volumes of mixtures of N,N-dimethylformamide with isobutanol, sec-butanol and t-pentanol, J. Chem. Soc., Faraday Trans. 1, 1988, 84(2), 529-537. [all data]

Rybalkin, Emel'yanov, et al., 1978
Rybalkin, V.I.; Emel'yanov, V.M.; Stupak, P.M.; Litovchenko, N.P.; Z'ola, M.I., Study of the heat capacity of initial compounds and reaction products in the production of metal dialkyldithiophosphates, B.S.R. Inst. Neftepererab. Neftekhim. Prom. (Kiev), 1978, (16), 48-50. [all data]

Paz Andrade, Paz, et al., 1970
Paz Andrade, M.I.; Paz, J.M.; Recacho, E., Contribucion a la microcalorimetria de los calores especificos de solidos y liquidos, An. Quim., 1970, 66, 961-967. [all data]

Swietoslawski and Zielenkiewicz, 1960
Swietoslawski, W.; Zielenkiewicz, A., Mean specific heat in homologous series of binary and ternary positive azeotropes, Bull. Acad. Pol. Sci. Ser. Sci. Chim., 1960, 8, 651-653. [all data]

Swietoslawski and Zielenkiewicz, 1958
Swietoslawski, W.; Zielenkiewicz, A., Mean specific heats of binary positive azeotropes, Bull. Acad. Pol. Sci. Ser. Sci. Chim., 1958, 6, 367-369. [all data]

Zhdanov, 1941
Zhdanov, A.K., Specific heats of some liquids and azeotropic mixtures, Zhur. Obshch. Khim., 1941, 11, 471-482. [all data]

Willams and Daniels, 1924
Willams, J.W.; Daniels, F., The specific heats of certain organic liquids at elevated temperatures, J. Am. Chem. Soc., 1924, 46, 903-917. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Shao, Baer, et al., 1988
Shao, J.D.; Baer, T.; Lewis, D.K., Dissociation dynamics of energy-selected ion-dipole complexes. 2. Butyl alcohol ions, J. Phys. Chem., 1988, 92, 5123. [all data]

Bowen and Maccoll, 1984
Bowen, R.D.; Maccoll, A., Low energy, low temperature mass spectra, Org. Mass Spectrom., 1984, 19, 379. [all data]

Holmes, Fingas, et al., 1981
Holmes, J.L.; Fingas, M.; Lossing, F.P., Towards a general scheme for estimating the heats of formation of organic ions in the gas phase. Part I. Odd-electron cations, Can. J. Chem., 1981, 59, 80. [all data]

Cocksey, Eland, et al., 1971
Cocksey, B.J.; Eland, J.H.D.; Danby, C.J., The effect of alkyl substitution on ionisation potential, J. Chem. Soc., 1971, (B), 790. [all data]

Peel and Willett, 1975
Peel, J.B.; Willett, G.D., Photoelectron spectroscopic studies of the higher alcohols, Aust. J. Chem., 1975, 28, 2357. [all data]

Holmes and Lossing, 1984
Holmes, J.L.; Lossing, F.P., Heats of formation of organic radicals from appearance energies, Int. J. Mass Spectrom. Ion Processes, 1984, 58, 113. [all data]

Haas and Harrison, 1993
Haas, M.J.; Harrison, A.G., The Fragmentation of Proton-Bound Cluster Ions and the Gas-Phase Acidities of Alcohols, Int. J. Mass Spectrom. Ion Proc., 1993, 124, 2, 115, https://doi.org/10.1016/0168-1176(93)80003-W . [all data]

Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr., The gas phase acidity scale from methanol to phenol, J. Am. Chem. Soc., 1979, 101, 6047. [all data]

Notes

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Symbols used in this document:

AE	Appearance energy
C_p,gas	Constant pressure heat capacity of gas
C_p,liquid	Constant pressure heat capacity of liquid
C_p,solid	Constant pressure heat capacity of solid
IE (evaluated)	Recommended ionization energy
S°_gas	Entropy of gas at standard conditions
S°_liquid	Entropy of liquid at standard conditions
S°_{solid,1 bar}	Entropy of solid at standard conditions (1 bar)
Δ_cH°_liquid	Enthalpy of combustion of liquid at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fH°_liquid	Enthalpy of formation of liquid at standard conditions
Δ_rG°	Free energy of reaction 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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