Mercury diiodide

• Formula: HgI₂
• Molecular weight: 454.40
• IUPAC Standard InChI: InChI=1S/Hg.2HI/h;2*1H/q+2;;/p-2 Copy

  
• IUPAC Standard InChIKey: YFDLHELOZYVNJE-UHFFFAOYSA-L Copy
• CAS Registry Number: 7774-29-0
• Chemical structure:
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• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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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 (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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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 by: William E. Acree, Jr., James S. Chickos

Enthalpy of vaporization

Enthalpy of fusion

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

Ionization energy determinations

Appearance energy determinations

References

Go To: Top, Gas 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.

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

Su, Zhu, et al., 2002
Su, Ching-Hua; Zhu, Shen; Ramachandran, N.; Burger, A., Beer law constants and vapor pressures of HgI2 over HgI2(s,l), Journal of Crystal Growth, 2002, 235, 1-4, 313-319, https://doi.org/10.1016/S0022-0248(01)01806-1 . [all data]

Linn, Tzeng, et al., 1983
Linn, S.H.; Tzeng, W.-B.; Brom, J.M., Jr.; Ng, C.Y., Molecular beam photoionization study of HgBr₂ and HgI₂, J. Chem. Phys., 1983, 78, 50. [all data]

Lee and Potts, 1981
Lee, E.P.F.; Potts, A.W., Fine structure in the He(I)/He(II) photoelectron spectra of the metal valence (d) shells of the group IIB dihalides, J. Electron Spectrosc. Relat. Phenom., 1981, 22, 247. [all data]

Eland, 1970
Eland, J.H.D., Photoelectron spectra and chemical bonding of mercury(II) compounds, Intern. J. Mass Spectrom. Ion Phys., 1970, 4, 37. [all data]

Kiser, Dillard, et al., 1969
Kiser, R.W.; Dillard, J.G.; Dugger, D.L., Mass spectrometry of inorganic halides, Advan. Chem. Ser., 1969, 72, 153. [all data]

Notes

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

• Symbols used in this document:
  

  AE	Appearance energy
  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
  ΔfusH	Enthalpy of fusion
  ΔvapH	Enthalpy of vaporization

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