Dipotassium

• Formula: K₂
• Molecular weight: 78.1966
• IUPAC Standard InChI: InChI=1S/2K Copy

  
• IUPAC Standard InChIKey: ZDHURYWHEBEGHO-UHFFFAOYSA-N Copy
• CAS Registry Number: 25681-80-5
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
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• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Ion clustering data
  • Constants of diatomic molecules
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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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.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
    C_p = heat capacity (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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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 evaluated as indicated in comments:
L - Sharon G. Lias

Data compiled as indicated in comments:
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
B - John E. Bartmess

Electron affinity determinations

Ionization energy determinations

Appearance energy determinations

References

Go To: Top, Gas phase thermochemistry 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.

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Eaton, Sarkas, et al., 1992
Eaton, J.G.; Sarkas, H.W.; Arnold, S.T.; Mchugh, K.M.; Bowen, K.H., Negative Ion Photoelectron Spectroscopy of the Heteronuclear Alkali-Metal Dimer and Trimer Anions - NaK-, KRb-, RbCS-, KCs-, Na2K-, and K2Cs, Chem. Phys. Lett., 1992, 193, 1-3, 141, https://doi.org/10.1016/0009-2614(92)85697-9 . [all data]

McHugh, Eaton, et al., 1989
McHugh, K.M.; Eaton, J.G.; Lee, G.H.; Sarkas, H.W.; Kidder, L.H.; Snodgrass, J.T.; Manaa, M.R.; Bowen, K.H., Photoelectron Spectra of the alkali metal cluster Anions: Na-,n=2-5, K-,n=2-7, Rb-,n=2-3, and Cs-,n=2-3, J. Chem. Phys., 1989, 91, 6, 3792, https://doi.org/10.1063/1.456861 . [all data]

Kappes, Radi, et al., 1985
Kappes, M.M.; Radi, P.; Schar, M.; Schumacher, E., Photoionization measurements on dialkali monohalides generated in supersonic nozzle beams, Chem. Phys. Lett., 1985, 113, 243. [all data]

Broyer, Chevaleyre, et al., 1985
Broyer, M.; Chevaleyre, J.; Delacretaz, G.; Fayet, P.; Woste, L., One- and two-photon ionization of alkaline clusters, Surf. Sci., 1985, 156, 342. [all data]

Leutwyler, Hofmann, et al., 1981
Leutwyler, S.; Hofmann, M.; Harri, H.-P.; Schumacher, E., The adiabatic ionization potentials of the alkali dimers Na₂, NaK and K₂, Chem. Phys. Lett., 1981, 77, 257. [all data]

Herrmann, Schumacher, et al., 1978
Herrmann, A.; Schumacher, E.; Woste, L., Preparation and photoionization potentials of molecules of sodium, potassium and mixed atoms, J. Chem. Phys., 1978, 68, 2327. [all data]

Herrmann, Leutwyler, et al., 1978
Herrmann, A.; Leutwyler, S.; Schumacher, E.; Woste, L., 38. On metal-atom clusters IV. Photoionization thresholds and multiphoton ionization spectra of alkali-metal molecules, Helv. Chim. Acta, 1978, 61, 453. [all data]

Zmbov, Wu, et al., 1977
Zmbov, K.F.; Wu, C.H.; Ihle, H.R., A mass spectrometric study of heteronuclear diatomic alkali metal molecules. Dissociation energies ionization potentials of NaLi, KLi, NaK, J. Chem. Phys., 1977, 67, 4603. [all data]

Foster, Leckenby, et al., 1969
Foster, P.J.; Leckenby, R.E.; Robbins, E.J., The ionization potentials of clustered alkali metal atoms, J. Phys. B:, 1969, 2, 478. [all data]

Robertson and Barrow, 1961
Robertson, E.W.; Barrow, R.F., Rotational analysis oi the C¹π_u-X1⁺_g system of K₂, and the ionisation potential of K₂, Proc. Chem. Soc., 1961, 329. [all data]

Notes

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• Symbols used in this document:
  

  AE	Appearance energy
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  ΔfH°gas	Enthalpy of formation of gas at standard conditions

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