Cyclopentane, 1,1-dimethyl-
- Formula: C7H14
- Molecular weight: 98.1861
- IUPAC Standard InChIKey: QWHNJUXXYKPLQM-UHFFFAOYSA-N
- CAS Registry Number: 1638-26-2
- 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: Gem-Dimethylcyclopentane; 1,1-Dimethylcyclopentane
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Condensed phase thermochemistry data
Go To: Top, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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:
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 |
---|---|---|---|---|---|
ΔfH°liquid | -172.1 ± 1.1 | kJ/mol | Cm | Johnson, Prosen, et al., 1949 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -4583.3 ± 1.0 | kJ/mol | Cm | Johnson, Prosen, et al., 1949 | Corresponding ΔfHºliquid = -172.0 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 265.01 | J/mol*K | N/A | Gross, Oliver, et al., 1953 | DH |
Constant pressure heat capacity of liquid
Cp,liquid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
187.36 | 299.81 | Gross, Oliver, et al., 1953 | T = 13 to 300 K. Unsmoothed experimental datum.; DH |
Phase change data
Go To: Top, Condensed phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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
DRB - Donald R. Burgess, Jr.
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 | 360.9 ± 0.7 | K | AVG | N/A | Average of 11 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 201. ± 6. | K | AVG | N/A | Average of 14 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 203.68 | K | N/A | Gross, Oliver, et al., 1953, 2 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.05 K; by adiabatic calorimeter; TRC |
Ttriple | 203.670 | K | N/A | Huffman, 1948 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.02 K; TRC |
Ttriple | 203.670 | K | N/A | Huffman, 1947 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.03 K; TRC |
Ttriple | 203.670 | K | N/A | Huffman, 1947 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.02 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 33.8 | kJ/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 33.8 | kJ/mol | N/A | Johnson, Prosen, et al., 1949 | DRB |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
34.0 | 299. | A | Stephenson and Malanowski, 1987 | Based on data from 284. to 363. K.; AC |
33.8 | 304. | N/A | Forziati, Norris, et al., 1949 | Based on data from 289. to 362. 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 |
---|---|---|---|---|---|
288.7 to 361.89 | 3.9547 | 1226.557 | -50.393 | Forziati, Norris, et al., 1949, 2 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
1.09 | 203.7 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
44.18 | 146.8 | Domalski and Hearing, 1996 | CAL |
5.34 | 203.7 |
Enthalpy of phase transition
ΔHtrs (kJ/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
6.4894 | 146.80 | crystaline, II | crystaline, I | Gross, Oliver, et al., 1953 | DH |
1.0786 | 203.68 | crystaline, I | liquid | Gross, Oliver, et al., 1953 | DH |
Entropy of phase transition
ΔStrs (J/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
44.21 | 146.80 | crystaline, II | crystaline, I | Gross, Oliver, et al., 1953 | DH |
5.30 | 203.68 | crystaline, I | liquid | Gross, Oliver, et al., 1953 | DH |
Gas phase ion energetics data
Go To: Top, Condensed phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Sharon G. Lias and Joel F. Liebman
Ionization energy determinations
IE (eV) | Method | Reference |
---|---|---|
9.46 ± 0.05 | EI | Holmes and Lossing, 1991 |
Mass spectrum (electron ionization)
Go To: Top, Condensed phase thermochemistry data, Phase change data, 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
NIST MS number | 935 |
References
Go To: Top, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Johnson, Prosen, et al., 1949
Johnson, W.H.; Prosen, E.J.; Rossini, F.D.,
Heats of combustion and isomerization of the six C7H14 alkylcyclopentanes,
J. Res. NBS, 1949, 42, 251-255. [all data]
Gross, Oliver, et al., 1953
Gross, M.E.; Oliver, G.D.; Huffman, H.M.,
Low-temperature thermal data for some C7H14 alkylcyclopentanes,
J. Am. Chem. Soc., 1953, 75, 2801-2804. [all data]
Gross, Oliver, et al., 1953, 2
Gross, M.E.; Oliver, G.D.; Huffman, H.M.,
Low temperature thermal data for some C7H14 alkylcyclopentanes,
J. Am. Chem. Soc., 1953, 75, 2801. [all data]
Huffman, 1948
Huffman, H.M.,
Personal Commun., U. S. Bur. Mines, Bartlesville, OK, 1948. [all data]
Huffman, 1947
Huffman, H.M.,
Personal Communication, U. S. Bur. Mines, Bartlesville, OK, 1947. [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]
Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw,
Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2
. [all data]
Forziati, Norris, et al., 1949
Forziati, Alphonse F.; Norris, William R.; Rossini, Frederick D.,
Vapor pressures and boiling points of sixty API-NBS hydrocarbons,
J. RES. NATL. BUR. STAN., 1949, 43, 6, 555-17, https://doi.org/10.6028/jres.043.050
. [all data]
Forziati, Norris, et al., 1949, 2
Forziati, A.F.; Norris, W.R.; Rossini, F.D.,
Vapor Pressures and Boiling Points of Sixty API-NBS Hydrocarbons,
J. Res. Natl. Bur. Stand. (U.S.), 1949, 43, 6, 555-563, https://doi.org/10.6028/jres.043.050
. [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]
Holmes and Lossing, 1991
Holmes, J.L.; Lossing, F.P.,
Ionization energies of homologous organic compounds and correlation with molecular size,
Org. Mass Spectrom., 1991, 26, 537. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), References
- Symbols used in this document:
Cp,liquid Constant pressure heat capacity of liquid S°liquid Entropy of liquid at standard conditions Tboil Boiling point Tfus Fusion (melting) point Ttriple Triple point temperature ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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