2H-Pyran, 3,4-dihydro-

• Formula: C₅H₈O
• Molecular weight: 84.1164
• IUPAC Standard InChI: InChI=1S/C5H8O/c1-2-4-6-5-3-1/h2,4H,1,3,5H2 Copy

  
• IUPAC Standard InChIKey: BUDQDWGNQVEFAC-UHFFFAOYSA-N Copy
• CAS Registry Number: 110-87-2
• 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.
• Species with the same structure:
  • Pyran, 2,3-dihydro-
  • Dihydropyran
• Other names: Dihydropyran; 2,3-Dihydro-4H-pyran; 2H-3,4-Dihydropyran; 3,4-Dihydro-2H-pyran; 3,4-Dihydropyran; 5,6-Dihydro-4H-pyran; 2,3-Dihydropyran; 3,4-Dihdro-2H-pyrane; 3,4-Dihydro-2-pyran; δ2-Dihydropyran; Pyran, dihydro-; 1,2-Pyran, 3,4-dihydro-; NSC 57860
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
• 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, 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
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Constant pressure heat capacity of gas

Condensed phase thermochemistry data

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

Phase change data

Go To: Top, Gas phase thermochemistry data, 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, 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 evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

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

References

Go To: Top, Gas phase thermochemistry data, 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.

Steele, Chirico, et al., 1989
Steele, W.V.; Chirico, R.D.; Nguyen, A.; Hossenlopp, I.A.; Smith, N.K., Determination of some pure compound ideal-gas enthalpies of formation, AIChE Symp. Ser., 1989, 85, 140-162. [all data]

Dorofeeva O.V., 1992
Dorofeeva O.V., Ideal gas thermodynamic properties of oxygen heterocyclic compounds. Part 2. Six-membered, seven-membered and eight-membered rings, Thermochim. Acta, 1992, 200, 121-150. [all data]

Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]

Moshkin, 1955
Moshkin, P.A., Vpr. Isolz. Pentozansoderzh. Syrya Tr. Vses. Soveshch. Riga, 1955, 1955, 225 (1958). [all data]

Schniepp and Geller, 1946
Schniepp, L.E.; Geller, H.H., Preparation of Dihydropyran. δ-Hydroxyvaleraldehyde and 1,5-Pentanediol from Tetrahydrofurfuryl Alcohol, J. Am. Chem. Soc., 1946, 68, 1646-8. [all data]

Anonymous, 1942
Anonymous, R., , Am. Pet. Inst. Res. Proj. 6, Natl. Bur. Stand., 1942. [all data]

Kobe and Mathews, 1970
Kobe, K.A.; Mathews, J.F., Critical Properties and Vapor Pressures of Some Organic Nitrogen and Oxygen Compounds, J. Chem. Eng. Data, 1970, 15, 182. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Bloch, Brogli, et al., 1978
Bloch, M.; Brogli, F.; Heilbronner, E.; Jones, T.B.; Prinzbach, H.; Schweikert, O., 138. Photoelectron spectra of unsaturated oxides. I. 1,4- dioxin and related systems, Helv. Chim. Acta, 1978, 61, 1388. [all data]

Planckaert, Doucet, et al., 1974
Planckaert, A.A.; Doucet, J.; Sandorfy, C., Comparative study of the vacuum ultraviolet absorption and photoelectron spectra of some simple ethers and thioethers, J. Chem. Phys., 1974, 60, 4846. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Batich, Heilbronner, et al., 1976
Batich, C.; Heilbronner, E.; Quinn, C.B.; Wiseman, J.R., The electronic structure of vinyl ethers and sulfides with interrupted conjugation examined by photoelectron spectroscopy, Helv. Chim. Acta, 1976, 59, 512. [all data]

Notes

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

• Symbols used in this document:
  

  Cp,gas	Constant pressure heat capacity of gas
  IE (evaluated)	Recommended ionization energy
  Pc	Critical pressure
  Tboil	Boiling point
  Tc	Critical temperature
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔvapH°	Enthalpy of vaporization 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.