Urea, methyl-
- Formula: C2H6N2O
- Molecular weight: 74.0818
- IUPAC Standard InChIKey: XGEGHDBEHXKFPX-UHFFFAOYSA-N
- CAS Registry Number: 598-50-5
- 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: Methylurea; Monomethylurea; N-Methylurea; 1-Methylurea; CH3NHCONH2; Methylmocovina
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Condensed phase thermochemistry data
Go To: Top, 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 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°solid | -332.78 ± 0.75 | kJ/mol | Ccb | Kabo, Miroshnichenko, et al., 1990 | see Simirsky, Kabo, et al., 1987 and Simirskii, Kabo, et al., 1986; ALS |
ΔfH°solid | -327.8 ± 1.4 | kJ/mol | Ccb | Finch and Smith, 1983 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -1311.74 ± 0.69 | kJ/mol | Ccb | Kabo, Miroshnichenko, et al., 1990 | see Simirsky, Kabo, et al., 1987 and Simirskii, Kabo, et al., 1986; ALS |
ΔcH°solid | -1316.8 ± 1.4 | kJ/mol | Ccb | Finch and Smith, 1983 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°solid,1 bar | 138.02 | J/mol*K | N/A | Kozyro, Kabo, et al., 1993 | DH |
Constant pressure heat capacity of solid
Cp,solid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
114.74 | 298.15 | Kozyro, Kabo, et al., 1993 | T = 5 to 350 K.; DH |
Phase change data
Go To: Top, Condensed phase thermochemistry 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 as indicated in comments:
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
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tfus | 373.8 | K | N/A | DellaGatta and Ferro, 1987 | Uncertainty assigned by TRC = 0.5 K; TRC |
Tfus | 375.3 | K | N/A | Zordan, Hurkot, et al., 1972 | Uncertainty assigned by TRC = 0.1 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 375.0 | K | N/A | Ferloni and DellaGatta, 1995 | Uncertainty assigned by TRC = 0.2 K; TRC |
Ttriple | 378. | K | N/A | Kabo, Miroshnichenko, et al., 1990, 2 | Uncertainty assigned by TRC = 0.00001 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔsubH° | 95.5 ± 0.5 | kJ/mol | GS | Emel'yanenko, Kabo, et al., 2006 | Based on data from 331. to 365. K.; AC |
ΔsubH° | 97.10 ± 0.40 | kJ/mol | C | Kozyro, Kabo, et al., 1993 | crystal phase; ALS |
ΔsubH° | 97.1 ± 0.4 | kJ/mol | N/A | Kozyro, Kabo, et al., 1993 | AC |
Enthalpy of sublimation
ΔsubH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
95.730 | 343. | N/A | Kozyro, Kabo, et al., 1993 | DH |
96.9 ± 1.2 | 347. | ME | Zaitsau, Kabo, et al., 2003 | Based on data from 322. to 371. K.; AC |
96.8 ± 1.2 | 350. | ME | Zaitsau, Kabo, et al., 2003 | Based on data from 322. to 371. K.; AC |
94.4 ± 0.8 | 350. | C | Zaitsau, Kabo, et al., 2003 | AC |
94.38 ± 0.85 | 343. | C | Kozyro, Kabo, et al., 1993 | Hfusion=13.6±2.0 kJ/mol; ALS |
94.4 ± 0.84 | 343. | C | Kozyro, Kabo, et al., 1993 | AC |
99.3 ± 0.7 | 337. | C | Kabo, Miroshnichenko, et al., 1990 | see Simirsky, Kabo, et al., 1987 and Simirskii, Kabo, et al., 1986; ALS |
94.9 ± 0.6 | 337. | C | Kabo, Miroshnichenko, et al., 1990 | AC |
93.3 ± 1.2 | 355. | TE | Piacente, Ferro, et al., 1990 | See also Ferro, Barone, et al., 1987.; AC |
87.3 | 348. | N/A | Ferro, Barone, et al., 1987 | AC |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
15.750 | 373.8 | N/A | Della Gatta and Ferro, 1987 | DH |
12.5 | 372. | DSC | Hashimoto, Tajima, et al., 2005 | AC |
16.6 | 375. | DSC | Ferloni and Gatta, 1995 | AC |
14.06 | 378.1 | N/A | Kabo, Miroshnichenko, et al., 1990 | AC |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
42.1 | 373.8 | Della Gatta and Ferro, 1987 | DH |
Gas phase ion energetics data
Go To: Top, Condensed phase thermochemistry data, 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:
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 |
---|---|---|---|
9.73 ± 0.05 | EI | Baldwin, Kirkien-Konasiewicz, et al., 1966 | RDSH |
9.66 | PE | Dougherty, Wittel, et al., 1976 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
CH2NO+ | 13.25 | ? | EI | Loudon and Webb, 1977 | LLK |
CH4N+ | 11.65 | ? | EI | Loudon and Webb, 1977 | LLK |
References
Go To: Top, Condensed phase thermochemistry data, 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.
Kabo, Miroshnichenko, et al., 1990
Kabo, G.Ya.; Miroshnichenko, E.A.; Frenkel, M.L.; Kozyro, A.A.; Simirskii, V.V.; Krasulin, A.P.; Vorob'eva, V.P.; Lebedev, Yu.A.,
Thermochemistry of urea alkyl derivatives,
Bull. Acad. Sci. USSR, Div. Chem. Sci., 1990, 662-667. [all data]
Simirsky, Kabo, et al., 1987
Simirsky, V.V.; Kabo, G.J.; Frenkel, M.L.,
Additivity of the enthalpies of formation of urea derivatives in the crystalline state,
J. Chem. Thermodyn., 1987, 19, 1121-1127. [all data]
Simirskii, Kabo, et al., 1986
Simirskii, V.V.; Kabo, G.Ya.; Frenkel, M.L.,
Enthalpies of combustion and of formation of monoalkyl derivatives of urea,
Russ. J. Phys. Chem. (Engl. Transl.), 1986, 60, 1233-1234. [all data]
Finch and Smith, 1983
Finch, A.; Smith, A.E.,
The standard enthalpy of formation of methylurea,
Thermochim. Acta, 1983, 66, 387-389. [all data]
Kozyro, Kabo, et al., 1993
Kozyro, A.A.; Kabo, G.J.; Krasulin, A.P.; Sevruk, V.M.; Simirsky, V.V.; Sheiman, M.S.; Frenkel, M.L.,
Thermodynamic properties of methylurea,
J. Chem. Thermodyn., 1993, 25, 1409-1417. [all data]
DellaGatta and Ferro, 1987
DellaGatta, G.; Ferro, D.,
Enthalpies of fusion and solid-to-solid transition, entropies of fusion for urea and twelve alkylurea,
Thermochim. Acta, 1987, 122, 143-52. [all data]
Zordan, Hurkot, et al., 1972
Zordan, T.A.; Hurkot, D.G.; Peterson, M.; Hepler, L.G.,
Enthalpies and entropies of melting from differential scanning calorimetry and freezing point depressions: urea, methylurea, 1, 1-dimethylurea, 1, 3- dimethylurea, tetramethylurea, and thiourea,
Thermochim. Acta, 1972, 5, 21. [all data]
Ferloni and DellaGatta, 1995
Ferloni, P.; DellaGatta, G.,
Heat capacities of urea, N-methylurea, N-ethylurea, N-(n)propylurea, and N- (n)butylurea in the range 200 to 360 K,
Thermochim. Acta, 1995, 266, 203-12. [all data]
Kabo, Miroshnichenko, et al., 1990, 2
Kabo, G.Ya.; Miroshnichenko, E.A.; Frenkel, M.L.; Kozyro, A.A.; Simirsky, V.V.; Krasulin, A.P.; Vorob'eva, V.P.; Lebedev, Yu.A.,
Thermochemistry of Alkyl Derivatives of Urea,
Izv. Akad. Nauk SSSR, Ser. Khim., 1990, No. 4, 750-5. [all data]
Emel'yanenko, Kabo, et al., 2006
Emel'yanenko, Vladimir N.; Kabo, Gennady J.; Verevkin, Sergey P.,
Measurement and Prediction of Thermochemical Properties: Improved Increments for the Estimation of Enthalpies of Sublimation and Standard Enthalpies of Formation of Alkyl Derivatives of Urea,
J. Chem. Eng. Data, 2006, 51, 1, 79-87, https://doi.org/10.1021/je050230z
. [all data]
Zaitsau, Kabo, et al., 2003
Zaitsau, Dz; Kabo, G.J.; Kozyro, A.A.; Sevruk, V.M.,
The effect of the failure of isotropy of a gas in an effusion cell on the vapor pressure and enthalpy of sublimation for alkyl derivatives of carbamide,
Thermochimica Acta, 2003, 406, 1-2, 17-28, https://doi.org/10.1016/S0040-6031(03)00231-4
. [all data]
Piacente, Ferro, et al., 1990
Piacente, V.; Ferro, D.; Gatta, G. Della,
Sublimation enthalpy of eleven alkyl derivatives of urea,
Thermochimica Acta, 1990, 158, 1, 79-85, https://doi.org/10.1016/0040-6031(90)80054-3
. [all data]
Ferro, Barone, et al., 1987
Ferro, D.; Barone, G.; Della Gatta, G.; Piacente, V.,
Vapour pressures and sublimation enthalpies of urea and some of its derivatives,
The Journal of Chemical Thermodynamics, 1987, 19, 9, 915-923, https://doi.org/10.1016/0021-9614(87)90038-3
. [all data]
Della Gatta and Ferro, 1987
Della Gatta, G.; Ferro, D.,
Enthalpies of fusion and solid-to-solid transition, entropies of fusion for urea and twelve alkylureas,
Thermochim. Acta, 1987, 122, 143-152. [all data]
Hashimoto, Tajima, et al., 2005
Hashimoto, Masao; Tajima, Fukue; Eda, Kazuo; Yamamura, Kimiaki; Okazaki, Tadashi,
Exploration of plastic-like phases in alkylurea systems. A thermal and X-ray study,
Journal of Molecular Structure, 2005, 734, 1-3, 23-33, https://doi.org/10.1016/j.molstruc.2004.08.008
. [all data]
Ferloni and Gatta, 1995
Ferloni, Paolo; Gatta, Giuseppe Della,
Heat capacities of urea, N-methylurea, N-ethylurea, N-(n)propylurea, and N-(n)butylurea in the range 200 to 360 K,
Thermochimica Acta, 1995, 266, 203-212, https://doi.org/10.1016/0040-6031(95)02453-0
. [all data]
Baldwin, Kirkien-Konasiewicz, et al., 1966
Baldwin, M.; Kirkien-Konasiewicz, A.; Loudon, A.G.; Maccoll, A.; Smith, D.,
Localised or delocalised charges in molecule-ions?,
Chem. Commun., 1966, 574. [all data]
Dougherty, Wittel, et al., 1976
Dougherty, D.; Wittel, K.; Meeks, J.; McGlynn, S.P.,
Photoelectron spectroscopy of carbonyls. Ureas, uracils, and thymine,
J. Am. Chem. Soc., 1976, 98, 3815. [all data]
Loudon and Webb, 1977
Loudon, A.G.; Webb, K.S.,
The nature of the [C2H6N]+ and [CH4N]+ ions formed by electron impact on methylated formamides, acetamides, ureas, thioureas and hexamethylphosphoramide,
Org. Mass Spectrom., 1977, 12, 283. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy Cp,solid Constant pressure heat capacity of solid S°solid,1 bar Entropy of solid at standard conditions (1 bar) Tfus Fusion (melting) point Ttriple Triple point temperature ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°solid Enthalpy of formation of solid at standard conditions ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔsubH Enthalpy of sublimation ΔsubH° Enthalpy of sublimation at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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