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
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• 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 (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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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.

Liquid 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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Solid 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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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

Reaction 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:
MS - José A. Martinho Simões
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

 (l) + 2 (cr) = 2 (l) +  (cr)

By formula: C₂H₆Hg (l) + 2I₂ (cr) = 2CH₃I (l) + HgI₂ (cr)

C₆H₁₄Hg (l) +  (cr) = 2C₃H₇HgI (cr)

By formula: C₆H₁₄Hg (l) + HgI₂ (cr) = 2C₃H₇HgI (cr)

C₆H₁₄Hg (l) +  (cr) = 2C₃H₇HgI (cr)

By formula: C₆H₁₄Hg (l) + HgI₂ (cr) = 2C₃H₇HgI (cr)

 (l) +  (cr) = 2 (cr)

By formula: C₂H₆Hg (l) + HgI₂ (cr) = 2CH₃HgI (cr)

 (l) +  (cr) = 2C₂H₅HgI (cr)

By formula: C₄H₁₀Hg (l) + HgI₂ (cr) = 2C₂H₅HgI (cr)

 (l) +  (cr) = 2 (cr)

By formula: C₁₂H₁₀Hg (l) + HgI₂ (cr) = 2C₆H₅HgI (cr)

2 +  = C₆H₁₄Hg + 2

By formula: 2C₃H₇I + HgI₂ = C₆H₁₄Hg + 2I₂

2 +  = C₆H₁₄Hg + 2

By formula: 2C₃H₇I + HgI₂ = C₆H₁₄Hg + 2I₂

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

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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]

Hartley, Pritchard, et al., 1950
Hartley, K.; Pritchard, H.O.; Skinner, H.A., Thermochemistry of metallic alkyls. III.?mercury dimethyl and mercury methyl halides, Trans. Faraday Soc., 1950, 46, 1019, https://doi.org/10.1039/tf9504601019 . [all data]

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

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds in Academic Press, New York, 1970. [all data]

Mortimer, Pritchard, et al., 1952
Mortimer, C.T.; Pritchard, H.O.; Skinner, H.A., Thermochemistry of metallic alkyls. Part V.?Mercury di-propyl and mercury di-isopropyl, Trans. Faraday Soc., 1952, 48, 220, https://doi.org/10.1039/tf9524800220 . [all data]

Hartley, Pritchard, et al., 1951
Hartley, K.; Pritchard, H.O.; Skinner, H.A., Thermochemistry of metallic alkyls. IV. Mercury diethyl and mercury diphenyl, Trans. Faraday Soc., 1951, 47, 254, https://doi.org/10.1039/tf9514700254 . [all data]

Mortimer, Pritchard, et al., 1952, 2
Mortimer, C.T.; Pritchard, H.O.; Skinner, H.A., Thermochemistry of metallic alkyls. Part V - Mercury di-propyl and mercury di-isopropyl, Trans. Faraday Soc., 1952, 48, 220-229. [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

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• 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)
  S°liquid,1 bar	Entropy of liquid at standard conditions (1 bar)
  S°solid	Entropy of solid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔvapH	Enthalpy of vaporization

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