Heptasulfur

• Formula: S₇
• Molecular weight: 224.455
• CAS Registry Number: 21459-04-1
• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
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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 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
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

Electron affinity determinations

Ionization 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]

Hunsicker, Jones, et al., 1995
Hunsicker, S.; Jones, R.O.; Gantefor, G., Rings and chains in sulfur cluster anions S- to S-9(-): Theory (simulated annealing) and experiment (photoelectron detachment), J. Chem. Phys., 1995, 102, 15, 5917, https://doi.org/10.1063/1.469326 . [all data]

Rosinger, Grade, et al., 1983
Rosinger, W.; Grade, M.; Hirschwald, W., Detection of ion states of S₂ to S₈ by electron impact, Int. J. Mass Spectrom. Ion Processes, 1983, 47, 239. [all data]

Drowart, Goldfinger, et al., 1968
Drowart, J.; Goldfinger, P.; Detry, D.; Rickert, H.; Keller, H., Mass spectrometric study of the equilibria in sulphur vapour generated by an electrochemical knudsen cell, Advan. Mass Spectrom., 1968, 4, 499. [all data]

Berkowitz and Lifshitz, 1968
Berkowitz, J.; Lifshitz, C., Photoionization of high temperature vapors. II. Sulfur molecular species, J. Chem. Phys., 1968, 48, 4346. [all data]

Berkowitz and Chupka, 1964
Berkowitz, J.; Chupka, W.A., Vaporization processes involving sulfur, J. Chem. Phys., 1964, 40, 287. [all data]

Notes

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

• Symbols used in this document:
  

  EA	Electron affinity
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)

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