3-Cyclobutene-1,2-dione, 3,4-dihydroxy-

• Formula: C₄H₂O₄
• Molecular weight: 114.0563
• IUPAC Standard InChI: InChI=1S/C4H2O4/c5-1-2(6)4(8)3(1)7/h5-6H Copy

  
• IUPAC Standard InChIKey: PWEBUXCTKOWPCW-UHFFFAOYSA-N Copy
• CAS Registry Number: 2892-51-5
• 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: Squaric acid; Cyclobutenedione, dihydroxy-; Quadratic acid; 1,2-Dihydroxycyclobutene-3,4-dione; 1,2-Diketo-3,4-dihydroxycyclobutene; 3,4-Dihydroxy-3-cyclobutene-1,2-dione; 1,2-Dihydroxy cyclobutenedione; 1,2-Dihydroxy-3,4-cyclobutenedione; Cyclobutene-1,2-dione, 3,4-dihydroxy-; 3,4-Dihydroxy-cyclobutene-1,2-dione; NSC 125692
• 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
  • References
  • Notes
• Other data available:
  • Mass spectrum (electron ionization)
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry 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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Condensed phase thermochemistry data

Go To: Top, Gas 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:
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

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry 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:
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

Enthalpy of sublimation

Enthalpy of phase transition

Entropy of phase transition

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Notes

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

Sellers, 1971
Sellers, P., Enthalpies of formation of squaric acid and the corresponding diethyl ether, Acta Chem. Scand., 1971, 25, 2194-2198. [all data]

DeWit, Offringa, et al., 1983
DeWit, H.G.M.; Offringa, J.C.A.; De Kruif, C.G.; Van Miltenburg, J.C., Thermodynamic properties of molecular organic crystals containing nitrogen, oxygen and sulfur. III. Molar heat capacities measured by differential scanning calorimetry, Thermochim. Acta, 1983, 65, 43-51. [all data]

Barth, Helwig, et al., 1979
Barth, E.; Helwig, J.; Maier, H.D.; Mser, H.E.; Petersson, J., Specific heat of the two dimensional antiferroelectric squaric acid, Z. Phys., 1979, B34, 393-397. [all data]

De Wit, Van Miltenburg, et al., 1983
De Wit, H.G.M.; Van Miltenburg, J.C.; De Kruif, C.G., Thermodynamic properties of molecular organic crystals containing nitrogen, oxygen, and sulphur 1. Vapour pressures and enthalpies of sublimation, The Journal of Chemical Thermodynamics, 1983, 15, 7, 651-663, https://doi.org/10.1016/0021-9614(83)90079-4 . [all data]

Sellers, Holm, et al., 1971
Sellers, Peter; Holm, J.L.; Welch, B.J.; Prelesnik, A.; Zupancic, I.; Ehrenberg, L., Enthalpies of Formation of Squaric Acid and the Corresponding Diethyl Ether., Acta Chem. Scand., 1971, 25, 2194-2198, https://doi.org/10.3891/acta.chem.scand.25-2194 . [all data]

Pedley and Rylance, 1977
Pedley, J.B.; Rylance, J., , Computer Analysed Thermochemical Data: Organic and Organometallic Compounds, University of Sussex, Brighton, 1977. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy 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
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.