Urea
- Formula: CH4N2O
- Molecular weight: 60.0553
- IUPAC Standard InChI: InChI=1S/CH4N2O/c2-1(3)4/h(H4,2,3,4)
- IUPAC Standard InChIKey: XSQUKJJJFZCRTK-UHFFFAOYSA-N
- CAS Registry Number: 57-13-6
- 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: Carbamide; Carbamimidic acid; Carbonyldiamide; Isourea; Pseudourea; Urea-13C; Ureaphil; Ureophil; Urevert; UR; (NH2)2CO; Carbonyl Diamine; Alphadrate; Aquacare; Aquadrate; B-I-K; Calmurid; Carbaderm; Keratinamin; NCI-C02119; Pastaron; Prespersion, 75 urea; Ultra Mide; Urepearl; Mocovina; Supercel 3000; Varioform II; Benural 70; Harnstoff; Basodexan; Bubber shet; Elaqua xx; Hyanit; Nutraplus; Onychomal; NSC 34375; Uroderm; Panafil (Salt/Mix); Cerovel (Salt/Mix); component of Artra Ashy Skin Cream (Salt/Mix)
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Gas phase ion energetics data
Go To: Top, 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:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Proton affinity at 298K
| Proton affinity (kcal/mol) | Reference | Comment |
|---|---|---|
| 207.6 ± 0.60 | Zheng and Cooks, 2002 | MM |
| 208.8 ± 1.2 | Wang, Ma, et al., 1998 | m-bromoaniline; p-fluorobenzamide; MM |
| 208.8 ± 1.2 | Wang, Ma, et al., 1998 | T = T(eff) = 410-560 KK; Acrylamide;m-Bromoaniline; MM |
Gas basicity at 298K
| Gas basicity (review) (kcal/mol) | Reference | Comment |
|---|---|---|
| 200.5 ± 0.72 | Zheng and Cooks, 2002 | MM |
| 202.2 ± 1.2 | Wang, Ma, et al., 1998 | m-bromoaniline; p-fluorobenzamide; MM |
| 201.1 ± 1.2 | Wang, Ma, et al., 1998 | T = T(eff) = 410-560 KK; Acrylamide;m-Bromoaniline; MM |
Protonation entropy at 298K
| Protonation entropy (cal/mol*K) | Reference | Comment |
|---|---|---|
| 2.2 | Zheng and Cooks, 2002 | MM |
| -0.45 | Wang, Ma, et al., 1998 | T = T(eff) = 410-560 KK; Acrylamide;m-Bromoaniline; MM |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 9.7 | PE | Debies and Rabalais, 1974 | LLK |
| 10.27 ± 0.05 | EI | Baldwin, Kirkien-Konasiewicz, et al., 1966 | RDSH |
| 9.8 | PE | Bieri, Asbrink, et al., 1982 | Vertical value; LBLHLM |
| 10.28 | PE | Dougherty, Wittel, et al., 1976 | Vertical value; LLK |
| 10.33 | PE | Mines and Thompson, 1975 | Vertical value; LLK |
| 10.15 | PE | Meeks, Arnett, et al., 1975 | Vertical value; LLK |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| CH2NO+ | 12.90 | ? | EI | Loudon and Webb, 1977 | LLK |
De-protonation reactions
CH3N2O- + =
By formula: CH3N2O- + H+ = CH4N2O
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 361.8 ± 2.8 | kcal/mol | CIDC | Ma, Wang, et al., 1998 | gas phase; H and S (20.5±1.8 eu) directly from kinetic method; B |
| ΔrH° | 362.5 ± 2.6 | kcal/mol | G+TS | Taft, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
| ΔrH° | 357.4 ± 2.1 | kcal/mol | EIAE | Muftakhov, Vasil'ev, et al., 1999 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 355.7 ± 3.2 | kcal/mol | H-TS | Ma, Wang, et al., 1998 | gas phase; H and S (20.5±1.8 eu) directly from kinetic method; B |
| ΔrG° | 355.5 ± 2.5 | kcal/mol | IMRE | Taft, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
References
Go To: Top, 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.
Zheng and Cooks, 2002
Zheng, X.; Cooks, R.G.,
Thermochemical determinations by the kinetic method with direct entropy corrrection,
J. Phys. Chem. A, 2002, 106, 9939. [all data]
Wang, Ma, et al., 1998
Wang, F.; Ma, S.G.; Zhang, D.X.; Cooks, R.G.,
Proton affinity and gas-phase basicity of urea,
J. Phys. Chem. A., 1998, 102, 2988. [all data]
Debies and Rabalais, 1974
Debies, T.P.; Rabalais, J.W.,
Electronic structure of amino acids and ureas,
J. Electron Spectrosc. Relat. Phenom., 1974, 3, 315. [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]
Bieri, Asbrink, et al., 1982
Bieri, G.; Asbrink, L.; Von Niessen, W.,
30.4-nm He(II) photoelectron spectra of organic molecules,
J. Electron Spectrosc. Relat. Phenom., 1982, 27, 129. [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]
Mines and Thompson, 1975
Mines, G.W.; Thompson, H.W.,
The photoelectron spectra of amides, thioamides, ureas and thioureas,
Spectrochim. Acta, 1975, 31, 137. [all data]
Meeks, Arnett, et al., 1975
Meeks, J.L.; Arnett, J.F.; Larson, D.B.; McGlynn, S.P.,
Photoelectron spectroscopy of carbonyls. Urea, oxamide, oxalic acid and oxamic acid,
J. Am. Chem. Soc., 1975, 97, 3905. [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]
Ma, Wang, et al., 1998
Ma, S.G.; Wang, F.; Cooks, R.G.,
Gas-phase acidity of urea,
J. Mass Spectrom., 1998, 33, 10, 943-949, https://doi.org/10.1002/(SICI)1096-9888(1998100)33:10<943::AID-JMS703>3.0.CO;2-B
. [all data]
Taft, 1987
Taft, R.W.,
The Nature and Analysis of Substitutent Electronic Effects,
Personal communication. See also Prog. Phys. Org. Chem., 1987, 16, 1. [all data]
Muftakhov, Vasil'ev, et al., 1999
Muftakhov, M.V.; Vasil'ev, Y.V.; Mazunov, V.A.,
Determination of electron affinity of carbonyl radicals by means of negative ion mass spectrometry,
Rapid Commun. Mass Spectrom., 1999, 13, 12, 1104-1108, https://doi.org/10.1002/(SICI)1097-0231(19990630)13:12<1104::AID-RCM619>3.0.CO;2-C
. [all data]
Notes
Go To: Top, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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