2,4(1H,3H)-Pyrimidinedione, 1,3-dimethyl-

• Formula: C₆H₈N₂O₂
• Molecular weight: 140.1399
• IUPAC Standard InChI: InChI=1S/C6H8N2O2/c1-7-4-3-5(9)8(2)6(7)10/h3-4H,1-2H3 Copy

  
• IUPAC Standard InChIKey: JSDBKAHWADVXFU-UHFFFAOYSA-N Copy
• CAS Registry Number: 874-14-6
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: Uracil, 1,3-dimethyl-; N,N'-Dimethyluracil; N1,N3-Dimethyluracil; 1,3-Dimethyluracil; 2,4-Dihydroxy-1,3-dimethylpyrimidine
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
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• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Condensed phase thermochemistry data

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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

Constant pressure heat capacity of solid

Phase change data

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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
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of sublimation

Entropy of sublimation

Enthalpy of fusion

Entropy of fusion

Enthalpy of phase transition

Gas phase ion energetics data

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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
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

Electron affinity determinations

Ionization energy determinations

De-protonation reactions

C₆H₇N₂O₂^- +  =

By formula: C₆H₇N₂O₂^- + H⁺ = C₆H₈N₂O₂

C₆H₇N₂O₂^- +  =

By formula: C₆H₇N₂O₂^- + H⁺ = C₆H₈N₂O₂

Mass spectrum (electron ionization)

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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

References

Go To: Top, Gas phase thermochemistry data, 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.

Imamura, Takahashi, et al., 1989
Imamura, A.; Takahashi, K.; Murata, S.; Sakiyama, M., Standard enthalpies of formation of trimethyl cyanurate, malonamide, and 1,3-dimethyluracil, J. Chem. Thermodyn., 1989, 21, 237-246. [all data]

Zielenkiewicz, Zielenkiewicz, et al., 1984
Zielenkiewicz, A.; Zielenkiewicz, W.; Malanowski, S., Thermodynamic Excess Functions of Dilute Aqueous Solutions of Alkylated Pyrimidines and Aminopurines and Caffeine, Thermochim. Acta, 1984, 74, 95. [all data]

Beak and White, 1982
Beak, P.; White, J.M., Relative enthalpies of 1,3-dimethyl-2,4-pyrimidinedione, 2,4-dimethoxypyrimidine, and 4-methoxy-1-methyl-2-pyrimidinone: estimation of the relative stabilities of two protomers of uracil, J. Am. Chem. Soc., 1982, 104, 7073-7077. [all data]

Murata, Sakiyama, et al., 1985
Murata, S.; Sakiyama, M.; Seki, S., Sublimation calorimetric studies using a calvet microcalorimeter, Thermochimica Acta, 1985, 88, 1, 121-126, https://doi.org/10.1016/0040-6031(85)85419-8 . [all data]

Clark, Peschel, et al., 1965
Clark, L.B.; Peschel, G.G.; Tinoco, I., Jr., Vapor spectra and heats of vaporization of some purine and pyrmidine bases, J. Phys. Chem., 1965, 69, 3615. [all data]

Brunetti, Piacente, et al., 2000
Brunetti, Bruno; Piacente, Vincenzo; Portalone, Gustavo, Sublimation Enthalpies of Some Methyl Derivatives of Uracil from Vapor Pressure Measurements, J. Chem. Eng. Data, 2000, 45, 2, 242-246, https://doi.org/10.1021/je9902802 . [all data]

Teplitsky, Yanson, et al., 1980
Teplitsky, A.B.; Yanson, I.K.; Glukhova, O.T.; Zielenkiwicz, A.; Zielenkiewicz, W.; Wierzchowski, K.L., Thermochemistry of aqueous solutions of alkylated nucleic acid bases, Biophysical Chemistry, 1980, 11, 1, 17-21, https://doi.org/10.1016/0301-4622(80)85003-4 . [all data]

Nowak, Szczepaniak, et al., 1978
Nowak, M.J.; Szczepaniak, K.; Barski, A.; Shugar, D.Z., Z. Naturforsch. C, 1978, 33C, 876. [all data]

Clark, Peschel, et al., 1965, 2
Clark, L.B.; Peschel, G.G.; Tinoco, I., Jr., Vapor spectra and heats of vaporization of some purine and pyrimidine bases, Not In System, 1965, 3615-3618. [all data]

Zielenkiewicz, Zielenkiewicz, et al., 1984, 2
Zielenkiewicz, A.; Zielenkiewicz, W.; Malanowski, S., Thermodynamic excess functions of diluted aqueous solutions of alkylated pyrimidines and amino purines, and caffeine, Thermochim. Acta, 1984, 74, 95-111. [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]

Sakiyama and Imamura, 1989
Sakiyama, M.; Imamura, A., Thermoanalytical characterization of 1,3-dimethyluracil and malonamide crystals, Thermochim. Acta, 1989, 142(2), 365-370. [all data]

Desfrancois, Abdoul-Carime, et al., 1999
Desfrancois, C.; Abdoul-Carime, H.; Carles, S.; Periquet, V.; Schermann, J.P.; Smith, D.M.A.; Adamowicz, L., Experimental and theoretical ab initio study of the influence of N-methylation on the dipole-bound electron affinities of thymine and uracil, J. Chem. Phys., 1999, 110, 24, 11876-11883, https://doi.org/10.1063/1.479175 . [all data]

Verkin, Sukodub, et al., 1976
Verkin, B.I.; Sukodub, L.F.; Yanson, I.K., Ionization potentials of nitrogenous bases of of nucleic acids, Dokl. Akad. Nauk SSSR, 1976, 228, 1452. [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]

Lee, 2005
Lee, J.K., Insights into nucleic acid reactivity through gas-phase experimental and computational studies, Int. J. Mass Spectrom., 2005, 240, 3, 261-272, https://doi.org/10.1016/j.ijms.2004.09.020 . [all data]

Gronert, Feng, et al., 2000
Gronert, S.; Feng, W.Y.; Chew, F.; Wu, W.M., The gas phase acid/base properties of 1,3,-dimethyluracil, 1-methyl-2-pyridone, and 1-methyl-4-pyridone: relevance to the mechanism of orotidine-5 '-monophosphate decarboxylase, Int. J. Mass Spectrom., 2000, 196, 251-258, https://doi.org/10.1016/S1387-3806(99)00191-8 . [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  EA	Electron affinity
  Tfus	Fusion (melting) point
  ΔHtrs	Enthalpy of phase transition
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions
  ΔsubS	Entropy of sublimation
  ΔvapH°	Enthalpy of vaporization at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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