Difluoromethane
- Formula: CH2F2
- Molecular weight: 52.0234
- IUPAC Standard InChIKey: RWRIWBAIICGTTQ-UHFFFAOYSA-N
- CAS Registry Number: 75-10-5
- 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: Freon 32; Methane, difluoro-; Methylene fluoride; Carbon fluoride hydride; Genetron 32; Methylene difluoride; CH2F2; R 32; HFC 32; R 32 (refrigerant)
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Phase change data
Go To: Top, Henry's Law data, Gas phase ion energetics data, Gas Chromatography, 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 |
---|---|---|---|---|---|
Tboil | 221.4 | K | N/A | PCR Inc., 1990 | BS |
Tboil | 221. | K | N/A | Filatov, Makarov, et al., 1968 | Uncertainty assigned by TRC = 2. K; TRC |
Tboil | 221.6 | K | N/A | Croll and Scott, 1964 | Uncertainty assigned by TRC = 0.3 K; TRC |
Tboil | 221.6 | K | N/A | Henne, Renoll, et al., 1939 | Uncertainty assigned by TRC = 1. K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 351.3 ± 0.1 | K | AVG | N/A | Average of 6 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 57.09 | atm | N/A | Shi, Zhu, et al., 1998 | Uncertainty assigned by TRC = 0.03 atm; by extrapolation of vapor pressure to Tc; TRC |
Pc | 57.09 | atm | N/A | Fu, Han, et al., 1995 | Uncertainty assigned by TRC = 0.04 atm; TRC |
Pc | 57.09 | atm | N/A | Higashi, 1994 | Uncertainty assigned by TRC = 0.09 atm; TRC |
Pc | 57.084 | atm | N/A | Sato, Sato, et al., 1994 | Uncertainty assigned by TRC = 0.025 atm; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 8.2 ± 0.1 | mol/l | AVG | N/A | Average of 7 values; Individual data points |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
4.92 | 230. | N/A | Kanungo, Oi, et al., 1987 | Based on data from 149. to 245. K.; AC |
4.76 | 271. | A | Stephenson and Malanowski, 1987 | Based on data from 256. to 321. K.; AC |
5.07 | 207. | A | Stephenson and Malanowski, 1987 | Based on data from 191. to 222. K.; AC |
4.85 | 243. | A | Stephenson and Malanowski, 1987 | Based on data from 191. to 258. K.; AC |
4.85 | 331. | A | Stephenson and Malanowski, 1987 | Based on data from 316. to 351. K.; AC |
5.07 | 206. | N/A | Malbrunot, Meunier, et al., 1968 | Based on data from 191. to 221. K.; AC |
4.92 | 227. | N/A | Malbrunot, Meunier, et al., 1968 | Based on data from 191. to 242. K.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
191.19 to 241.33 | 4.25653 | 821.092 | -28.554 | Malbrunot, Meunier, et al., 1968 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
1.04 | 136.4 | L«65533»ddecke and Magee, 1996 | AC |
Henry's Law data
Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, 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: Rolf Sander
Henry's Law constant (water solution)
kH(T) = k°H exp(d(ln(kH))/d(1/T) ((1/T) - 1/(298.15 K)))
k°H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(kH))/d(1/T) = Temperature dependence constant (K)
k°H (mol/(kg*bar)) | d(ln(kH))/d(1/T) (K) | Method | Reference | Comment |
---|---|---|---|---|
0.086 | Q | N/A | missing citation give several references for the Henry's law constants but don't assign them to specific species. |
Gas phase ion energetics data
Go To: Top, Phase change data, Henry's Law data, Gas Chromatography, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 12.71 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 148.3 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 140.9 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
12.70 | PE | Pullen, Carlson, et al., 1970 | RDSH |
12.72 | PE | Brundle, Robin, et al., 1970 | RDSH |
13.27 | EI | Harshbarger, Robin, et al., 1973 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
CF+ | 18.8 | ? | EI | Lifshitz and Long, 1965 | RDSH |
CF2+ | 14.8 ± 0.4 | H2 | EI | Steele, 1964 | RDSH |
CHF+ | 17.7 | ? | EI | Lifshitz and Long, 1965 | RDSH |
CHF2+ | 13.11 | H | EI | Lossing, 1972 | LLK |
CHF2+ | 13.14 ± 0.02 | H | EI | Martin, Lampe, et al., 1966 | RDSH |
CHF2+ | 13.1 | H | EI | Lifshitz and Long, 1965 | RDSH |
CH2F+ | 14.06 | F | EI | Lossing, 1972 | LLK |
CH2F+ | 15.28 | F | EI | Lifshitz and Long, 1965 | RDSH |
De-protonation reactions
CHF2- + =
By formula: CHF2- + H+ = CH2F2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 389.0 ± 3.5 | kcal/mol | CIDT | Graul and Squires, 1990 | gas phase; G2 calculations( Lee, Dyke, et al., 1998) predict ΔHacid = 399 kcal/mol; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 381.2 ± 3.6 | kcal/mol | H-TS | Graul and Squires, 1990 | gas phase; G2 calculations( Lee, Dyke, et al., 1998) predict ΔHacid = 399 kcal/mol; B |
ΔrG° | 379.0 ± 6.0 | kcal/mol | IMRB | Sullivan, 1977 | gas phase; B |
Gas Chromatography
Go To: Top, Phase change data, Henry's Law 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
Normal alkane RI, non-polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | OV-101 | 230. | Zenkevich, 2005 | 25. m/0.20 mm/0.10 μm, N2/He, 6. K/min; Tstart: 50. C; Tend: 250. C |
Normal alkane RI, non-polar column, custom temperature program
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | Porapack Q | 183. | Zenkevich and Rodin, 2004 | Program: not specified |
References
Go To: Top, Phase change data, Henry's Law data, Gas phase ion energetics data, Gas Chromatography, 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]
Filatov, Makarov, et al., 1968
Filatov, A.S.; Makarov, S.P.; Yakubovich, A.Ya.,
Halogenation of 1,1,1-Trifluoroazomethane,
Zh. Obshch. Khim., 1968, 38, 33. [all data]
Croll and Scott, 1964
Croll, I.M.; Scott, R.L.,
Fluorocarbon Solutions at Low Termperatures IV. The Liquid Mixtures CH4 + CClF3, CH2F2 + CClF3, CHF3 + CClF3, CF4 + CClF3, C2H6 + CClF3, C2H6 + CF4, and CHF3 + CF4,
J. Phys. Chem., 1964, 68, 3853. [all data]
Henne, Renoll, et al., 1939
Henne, A.L.; Renoll, M.W.; Leicester, H.M.,
J. Am. Chem. Soc., 1939, 61, 938. [all data]
Shi, Zhu, et al., 1998
Shi, L.; Zhu, M.; Han, L.; Duan, Y.; Sun, L.; Fu, Y.-D.,
Thermophysical Properties of Difluoromethane (HFC-32),
Science in China, Ser. E, 1998, 41, 435-42. [all data]
Fu, Han, et al., 1995
Fu, Y.D.; Han, L.-Z.; Zhu, M.-S.,
PVT properties, vapor pressures and critical parameters of HFC-32,
Fluid Phase Equilib., 1995, 111, 273-86. [all data]
Higashi, 1994
Higashi, Y.,
Critical parameters for HFC134a, HFC32 and HFC125,
Int. J. Refrig., 1994, 17, 524-531. [all data]
Sato, Sato, et al., 1994
Sato, T.; Sato, H.; Watanabe, K.,
PVT Property Measurements for Difluoromethane,
J. Chem. Eng. Data, 1994, 39, 851-4. [all data]
Kanungo, Oi, et al., 1987
Kanungo, Arundhati.; Oi, Takao.; Popowicz, Anthony.; Ishida, Takanobu.,
Vapor pressure isotope effects in liquid methylene difluoride,
J. Phys. Chem., 1987, 91, 15, 4198-4203, https://doi.org/10.1021/j100299a049
. [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]
Malbrunot, Meunier, et al., 1968
Malbrunot, P.F.; Meunier, P.A.; Scatena, Georges M.; Mears, Whitney H.; Murphy, Kevin Paul.; Sinka, Joseph V.,
Pressure-volume-temperature behavior of difluoromethane,
J. Chem. Eng. Data, 1968, 13, 1, 16-21, https://doi.org/10.1021/je60036a006
. [all data]
L«65533»ddecke and Magee, 1996
L«65533»ddecke, T.O.; Magee, J.W.,
Molar heat capacity at constant volume of difluoromethane (R32) and pentafluoroethane (R125) from the triple-point temperature to 345 K at pressures to 35 MPa,
Int J Thermophys, 1996, 17, 4, 823-849, https://doi.org/10.1007/BF01439192
. [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]
Pullen, Carlson, et al., 1970
Pullen, B.P.; Carlson, T.A.; Moddeman, W.E.; Schweitzer, G.K.; Bull, W.E.,
Photoelectron spectra of methane, silane, germane, methyl fluoride, difluoromethane, and trifluoromethane,
J. Chem. Phys., 1970, 53, 768. [all data]
Brundle, Robin, et al., 1970
Brundle, C.R.; Robin, M.B.; Basch, H.,
Electronic energies and electronic structures of the fluoromethanes,
J. Chem. Phys., 1970, 53, 2196. [all data]
Harshbarger, Robin, et al., 1973
Harshbarger, W.R.; Robin, M.B.; Lassettre, E.N.,
The electron impact spectra of the fluoromethanes,
J. Electron Spectrosc. Relat. Phenom., 1973, 1, 319. [all data]
Lifshitz and Long, 1965
Lifshitz, C.; Long, F.A.,
Appearance potentials and mass spectra of fluorinated ethylenes. II. Heats offormation of fluorinated species and their positive ions,
J. Phys. Chem., 1965, 69, 3731. [all data]
Steele, 1964
Steele, W.C.,
Appearance potentials of the difluoromethylene positive ion,
J. Phys. Chem., 1964, 68, 2359. [all data]
Lossing, 1972
Lossing, F.P.,
Free radicals by mass spectrometry. XLIV. Ionization potentials bond dissociation energies for chloro-and fluoromethyl radicals,
Bull. Soc. Chim. Belg., 1972, 81, 125. [all data]
Martin, Lampe, et al., 1966
Martin, R.H.; Lampe, F.W.; Taft, R.W.,
An electron-impact study of ionization and dissociation in methoxy- and halogen- substituted methanes,
J. Am. Chem. Soc., 1966, 88, 1353. [all data]
Graul and Squires, 1990
Graul, S.T.; Squires, R.R.,
Gas-Phase Acidities Derived from Threshold Energies for Activated Reactions,
J. Am. Chem. Soc., 1990, 112, 7, 2517, https://doi.org/10.1021/ja00163a007
. [all data]
Lee, Dyke, et al., 1998
Lee, E.P.F.; Dyke, J.M.; Mayhew, C.A.,
Study of the OH-+CH2F2 reaction by selected ion flow tube experiments and ab initio calculations,
J. Phys. Chem. A, 1998, 102, 43, 8349-8354, https://doi.org/10.1021/jp982224y
. [all data]
Sullivan, 1977
Sullivan, S.A.,
Thesis, Cal. Inst. Tech. thesis,, 1977. [all data]
Zenkevich, 2005
Zenkevich, I.G.,
Experimentally measured retention indices., 2005. [all data]
Zenkevich and Rodin, 2004
Zenkevich, I.G.; Rodin, A.A.,
Gas chromatographic identification of some volatile toxic fluorine containing compounds by precalculated retention indices,
J. Ecol. Chem. (Rus.), 2004, 13, 1, 22-28. [all data]
Notes
Go To: Top, Phase change data, Henry's Law data, Gas phase ion energetics data, Gas Chromatography, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy Pc Critical pressure Tboil Boiling point Tc Critical temperature d(ln(kH))/d(1/T) Temperature dependence parameter for Henry's Law constant k°H Henry's Law constant at 298.15K ΔfusH Enthalpy of fusion ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔvapH Enthalpy of vaporization ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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