Difluoromethane
Formula: CH2F2
InChI=1S/CH2F2/c2-1-3/h1H2
IUPAC Standard InChIKey: RWRIWBAIICGTTQ-UHFFFAOYSA-N
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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fH°gas -107.71 kcal/mol Review Chase, 1998 Data last reviewed in December, 1969
fH°gas -108.08 ± 0.22 kcal/mol Ccr Neugebauer and Margrave, 1958 Corrected for CODATA value of «DELTA»fH; ALS
cH°gas -139.36 kcal/mol Ccr Neugebauer and Margrave, 1958 Corrected for CODATA value of «DELTA»fH; ALS
S°gas,1 bar 58.963 cal/mol*K Review Chase, 1998 Data last reviewed in December, 1969
-1.457620 22.62800
-108.5430 -124.1750
Data last reviewed in December, 1969 Data last reviewed in December, 1969
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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
Tc 351.3 ± 0.1 K AVG N/A Average of 6 values; Individual data points
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
c 8.2 ± 0.1 mol/l AVG N/A Average of 7 values; Individual data points
4.92 230. N/A Kanungo, Oi, et al., 1987 Based on data from 149. - 245. K.; AC
4.76 271. A Stephenson and Malanowski, 1987 Based on data from 256. - 321. K.; AC
5.07 206. N/A Malbrunot, Meunier, et al., 1968 Based on data from 191. - 221. K.; AC
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
191.19 - 241.33 4.25653 821.092 -28.554 Malbrunot, Meunier, et al., 1968 Coefficents calculated by NIST from author's data.
Enthalpy of fusion
fusH (kcal/mol)
1.04 136.4 L«65533»ddecke and Magee, 1996 AC
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MS - José A. Martinho Simões
CHF2- + =
By formula: CHF2- + H+ = CH2F2
rH° 389.0 ± 3.5 kcal/mol CIDT Graul and Squires, 1990 gas phase; G2 calculations( Lee, Dyke, et al., 1998) predict «DELTA»Hacid = 399 kcal/mol; B
rG° 381.2 ± 3.6 kcal/mol H-TS Graul and Squires, 1990 gas phase; G2 calculations( Lee, Dyke, et al., 1998) predict «DELTA»Hacid = 399 kcal/mol; B
rG° 379.0 ± 6.0 kcal/mol IMRB Sullivan, 1977 gas phase; B
By formula: Li+ + CH2F2 = (Li+ CH2F2)
rH° 26.5 kcal/mol ICR Staley and Beauchamp, 1975 gas phase; switching reaction(Li+)H2O, from graph; Dzidic and Kebarle, 1970 interpolated; M
C5O5W (g) + (g) = C6H2F2O5W (g)
By formula: C5O5W (g) + CH2F2 (g) = C6H2F2O5W (g)
rH° >-5.00 kcal/mol EqG Brown, Ishikawa, et al., 1990 Temperature range: ca. 300-350 K; MS
By formula: CH2F2 + Br2 = HBr + CHBrF2
rH° -9.54 ± 0.07 kcal/mol Eqk Okafo and Whittle, 1974 gas phase; ALS
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Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), Notes
Neugebauer and Margrave, 1958
Neugebauer, C.A.; Margrave, J.L., The heats of formation of CHF3 and CH2F2, J. Phys. Chem., 1958, 62, 1043-1048. [all data]
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]
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]
Staley and Beauchamp, 1975
Staley, R.H.; Beauchamp, J.L., Intrinsic Acid - Base Properties of Molecules. Binding Energies of Li+ to pi - and n - Donor Bases, J. Am. Chem. Soc., 1975, 97, 20, 5920, https://doi.org/10.1021/ja00853a050 . [all data]
Dzidic and Kebarle, 1970
Dzidic, I.; Kebarle, P., Hydration of the Alkali Ions in the Gas Phase. Enthalpies and Entropies of Reactions M+(H2O)n-1 + H2O = M+(H2O)n, J. Phys. Chem., 1970, 74, 7, 1466, https://doi.org/10.1021/j100702a013 . [all data]
Brown, Ishikawa, et al., 1990
Brown, C.E.; Ishikawa, Y.; Hackett, P.A.; Rayner, D.M., J. Am. Chem. Soc., 1990, 112, 2530. [all data]
Okafo and Whittle, 1974
Okafo, E.N.; Whittle, E., Bond dissociation energies from equilibrium studies. Part 5.-The equilibria Br2 + CH2F2 = HBr + CHF2Br and Br2 + CH3F = HBr + CH2FBr. Determination of D(CHF2-Br) and «DELTA»H°f (CHF2Br,g), Trans. Faraday Soc., 1974, 17, 1366-1375. [all data]
Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), References
Pc Critical pressure
Tc Critical temperature
cH°gas Enthalpy of combustion of gas at standard conditions
fusH Enthalpy of fusion
c Critical density