Butane, 2,2-dimethyl-
- Formula: C6H14
- Molecular weight: 86.1754
- IUPAC Standard InChIKey: HNRMPXKDFBEGFZ-UHFFFAOYSA-N
- CAS Registry Number: 75-83-2
- 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: Neohexane; 2,2-Dimethylbutane; (CH3)3CCH2CH3; UN 1208
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- Options:
Data at NIST subscription sites:
- NIST / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data)
- NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)
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, Gas phase ion energetics data, 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
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 322.9 ± 0.1 | K | AVG | N/A | Average of 46 out of 54 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 173. ± 2. | K | AVG | N/A | Average of 24 out of 28 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 174. ± 2. | K | AVG | N/A | Average of 6 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 489.0 ± 0.5 | K | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 30.6 ± 0.2 | atm | N/A | Daubert, 1996 | |
Pc | 30.6179 | atm | N/A | Genco, Teja, et al., 1980 | Uncertainty assigned by TRC = 0.05 atm; TRC |
Pc | 30.61 | atm | N/A | Kay and Young, 1975 | Uncertainty assigned by TRC = 0.03 atm; TRC |
Pc | 30.6700 | atm | N/A | Kay, 1946 | Uncertainty assigned by TRC = 0.09998 atm; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.358 | l/mol | N/A | Daubert, 1996 | |
Vc | 0.358 | l/mol | N/A | Genco, Teja, et al., 1980 | Uncertainty assigned by TRC = 0.001 l/mol; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.80 ± 0.02 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.79 | mol/l | N/A | Kay, 1946 | Uncertainty assigned by TRC = 0.02 mol/l; by extrapolation of rectilinear diameter to Tc; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 6.675 | kcal/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 6.62 | kcal/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 6.616 | kcal/mol | C | Osborne and Ginnings, 1947 | ALS |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
6.288 | 322.9 | N/A | Majer and Svoboda, 1985 | |
6.86 | 288. | N/A | Nicolini and Laffitte, 1949 | Based on data from 273. to 318. K. See also Boublik, Fried, et al., 1984.; AC |
6.64 ± 0.02 | 296. | C | Waddington and Douslin, 1947 | AC |
6.29 ± 0.02 | 323. | C | Waddington and Douslin, 1947 | AC |
6.98 | 274. | N/A | Kilpatrick and Pitzer, 1946 | Based on data from 211. to 289. K.; AC |
6.76 | 303. | MM | Willingham, Taylor, et al., 1945 | Based on data from 288. to 323. K.; AC |
Enthalpy of vaporization
ΔvapH =
A exp(-βTr) (1 − Tr)β
ΔvapH =
Enthalpy of vaporization (at saturation pressure)
(kcal/mol)
Tr = reduced temperature (T / Tc)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A (kcal/mol) | β | Tc (K) | Reference | Comment |
---|---|---|---|---|---|
296. to 323. | 10.02 | 0.2675 | 488.7 | Majer and Svoboda, 1985 |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
210.99 to 289.38 | 3.7325 | 1022.204 | -49.529 | Kilpatrick and Pitzer, 1946 | Coefficents calculated by NIST from author's data. |
288.53 to 323.68 | 3.87402 | 1081.176 | -43.807 | Williamham, Taylor, et al., 1945 |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
0.14 | 174.3 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
10.17 | 126.8 | Domalski and Hearing, 1996 | CAL |
0.483 | 140.8 | ||
0.791 | 174.3 |
Enthalpy of phase transition
ΔHtrs (kcal/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
1.293 | 126.81 | crystaline, III | crystaline, II | Douslin and Huffman, 1946 | DH |
0.06819 | 140.79 | crystaline, II | crystaline, I | Douslin and Huffman, 1946 | DH |
0.1384 | 174.28 | crystaline, I | liquid | Douslin and Huffman, 1946 | DH |
1.289 | 126.81 | crystaline, III | crystaline, II | Kilpatrick and Pitzer, 1946 | DH |
0.0676 | 140.88 | crystaline, II | crystaline, I | Kilpatrick and Pitzer, 1946 | DH |
0.138 | 174.66 | crystaline, I | liquid | Kilpatrick and Pitzer, 1946 | DH |
1.095 | 127.11 | crystaline, II | crystaline, I | Stull, 1937 | DH |
0.111 | 172.13 | crystaline, I | liquid | Stull, 1937 | DH |
Entropy of phase transition
ΔStrs (cal/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
10.20 | 126.81 | crystaline, III | crystaline, II | Douslin and Huffman, 1946 | DH |
0.485 | 140.79 | crystaline, II | crystaline, I | Douslin and Huffman, 1946 | DH |
0.793 | 174.28 | crystaline, I | liquid | Douslin and Huffman, 1946 | DH |
10.2 | 126.81 | crystaline, III | crystaline, II | Kilpatrick and Pitzer, 1946 | DH |
0.480 | 140.88 | crystaline, II | crystaline, I | Kilpatrick and Pitzer, 1946 | DH |
0.796 | 174.66 | crystaline, I | liquid | Kilpatrick and Pitzer, 1946 | DH |
8.614 | 127.11 | crystaline, II | crystaline, I | Stull, 1937 | DH |
0.645 | 172.13 | crystaline, I | liquid | Stull, 1937 | DH |
Gas phase ion energetics data
Go To: Top, Phase change data, 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:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.07 | EST | Luo and Pacey, 1992 | LL |
9.79 | EQ | Lias, Ausloos, et al., 1976 | LLK |
10.06 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C4H8+ | 10.23 ± 0.015 | C2H6 | PI | Steiner, Giese, et al., 1961 | RDSH |
C4H9+ | 10.60 ± 0.025 | C2H5 | PI | Steiner, Giese, et al., 1961 | RDSH |
C5H10+ | 10.28 ± 0.02 | CH4 | PI | Steiner, Giese, et al., 1961 | RDSH |
C5H11+ | 10.555 ± 0.045 | CH3 | PI | Steiner, Giese, et al., 1961 | RDSH |
References
Go To: Top, Phase change data, Gas phase ion energetics data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Daubert, 1996
Daubert, T.E.,
Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes,
J. Chem. Eng. Data, 1996, 41, 365-372. [all data]
Genco, Teja, et al., 1980
Genco, J.M.; Teja, A.S.; Kay, W.B.,
Study of the critical and azeotropic behavior of binary mixtures I critical states of perfluoromethylcyclohexane + isomeric hexane systems,
J. Chem. Eng. Data, 1980, 25, 350. [all data]
Kay and Young, 1975
Kay, W.B.; Young, C.L.,
Gas-liquid critical properties. Tetradecafluoromethylcyclohexane( perfluoromethylcyclohexane)-2,2-dimethylbutane,
Int. DATA Ser., Sel. Data Mixtures, Ser. A, 1975, No. 1, 58. [all data]
Kay, 1946
Kay, W.B.,
The Vapor Pressures and Saturated Liquid and Vapor Densities of the Isomeric Hexanes,
J. Am. Chem. Soc., 1946, 68, 1336. [all data]
Majer and Svoboda, 1985
Majer, V.; Svoboda, V.,
Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]
Reid, 1972
Reid, Robert C.,
Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00,
AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637
. [all data]
Osborne and Ginnings, 1947
Osborne, N.S.; Ginnings, D.C.,
Measurements of heat of vaporization and heat capacity of a number of hydrocarbons,
J. Res. NBS, 1947, 39, 453-477. [all data]
Nicolini and Laffitte, 1949
Nicolini, E.; Laffitte, P.,
Compt. Rend., 1949, 229, 757. [all data]
Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E.,
The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [all data]
Waddington and Douslin, 1947
Waddington, Guy; Douslin, Donald R.,
Experimental Vapor Heat Capacities and Heats of Vaporization of n-Hexane and 2,2-Dimethylbutane 1,
J. Am. Chem. Soc., 1947, 69, 10, 2275-2279, https://doi.org/10.1021/ja01202a011
. [all data]
Kilpatrick and Pitzer, 1946
Kilpatrick, J.E.; Pitzer, K.S.,
The thermodynamics of 2,2-dimethylbutane, including the heat capacity, heats of transitions, fusion and vaporization and the entropy,
J. Am. Chem. Soc., 1946, 68, 1066-1072. [all data]
Willingham, Taylor, et al., 1945
Willingham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D.,
Vapor pressures and boiling points of some paraffin, alkylcyclopentane, alkylcyclohexane, and alkylbenzene hydrocarbons,
J. RES. NATL. BUR. STAN., 1945, 35, 3, 219-17, https://doi.org/10.6028/jres.035.009
. [all data]
Williamham, Taylor, et al., 1945
Williamham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D.,
Vapor Pressures and Boiling Points of Some Paraffin, Alkylcyclopentane, Alkylcyclohexane, and Alkylbenzene Hydrocarbons,
J. Res. Natl. Bur. Stand. (U.S.), 1945, 35, 3, 219-244, https://doi.org/10.6028/jres.035.009
. [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]
Douslin and Huffman, 1946
Douslin, D.R.; Huffman, H.M.,
Low-temperature thermal data on the five isometric hexanes,
J. Am. Chem. Soc., 1946, 68, 1704-1708. [all data]
Stull, 1937
Stull, D.R.,
A semi-micro calorimeter for measuring heat capacities at low temperatures,
J. Am. Chem. Soc., 1937, 59, 2726-2733. [all data]
Luo and Pacey, 1992
Luo, Y.-R.; Pacey, P.D.,
Effects of alkyl substitution on ionization energies of alkanes and haloalkanes and on heats of formation of their molecular cations. Part 2. Alkanes and chloro-, bromo- and iodoalkanes,
Int. J. Mass Spectrom. Ion Processes, 1992, 112, 63. [all data]
Lias, Ausloos, et al., 1976
Lias, S.G.; Ausloos, P.; Horvath, Z.,
Charge transfer reactions in alkane and cycloalkane systems. Estimated ionization potentials,
Int. J. Chem. Kinet., 1976, 8, 725. [all data]
Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J.,
Ionization potentials of some molecules,
J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]
Steiner, Giese, et al., 1961
Steiner, B.; Giese, C.F.; Inghram, M.G.,
Photoionization of alkanes. Dissociation of excited molecular ions,
J. Chem. Phys., 1961, 34, 189. [all data]
Notes
Go To: Top, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy Pc Critical pressure Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point Ttriple Triple point temperature Vc Critical volume ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.