Cyclic octaatomic sulfur
- Formula: S8
- Molecular weight: 256.520
- IUPAC Standard InChI: InChI=1S/S8/c1-2-4-6-8-7-5-3-1
- IUPAC Standard InChIKey: JLQNHALFVCURHW-UHFFFAOYSA-N
- CAS Registry Number: 10544-50-0
- Chemical structure:
This structure is also available as a 2d Mol file - Other names: Sulfur (S8); Sulfur octamer; Sulfur, mol. (S8); Cyclooctasulfur; Octathiocane; Orthorhombic sulfur; Sulfur molecule (S8); S8; Cyclooctasulphur; Octasulfur; 115725-44-5; Sulfur
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Gas phase thermochemistry data
Go To: Top, 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.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| S°gas,1 bar | 102.83 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in September, 1977 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = 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
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
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| Temperature (K) | 298. to 6000. |
|---|---|
| A | 43.18110 |
| B | 0.458649 |
| C | -0.124314 |
| D | 0.010610 |
| E | -0.542580 |
| F | -14.71330 |
| G | 151.9000 |
| H | 0.000000 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in September, 1977 |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry 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:
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
| EA (eV) | Method | Reference | Comment |
|---|---|---|---|
| 3.590 ± 0.050 | LPD | Hunsicker, Jones, et al., 1995 | Vertical Detachment Energy: 3.87 eV.; B |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 9.3 ± 0.2 | EI | Rosinger, Grade, et al., 1983 | LBLHLM |
| 9.04 ± 0.03 | PI | Berkowitz and Lifshitz, 1968 | RDSH |
| 9.6 ± 0.2 | EI | Berkowitz and Chupka, 1964 | RDSH |
| 7.3 ± 0.3 | EI | Hagemann, 1962 | RDSH |
| 9.40 | PE | Richardson and Weinberger, 1975 | Vertical value; LLK |
| 9.23 | PE | Boschi and Schmidt, 1973 | Vertical value; LLK |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| S3+ | 12.6 ± 0.5 | ? | EI | Berkowitz and Chupka, 1964 | RDSH |
| S4+ | 12.5 ± 0.3 | ? | EI | Berkowitz and Chupka, 1964 | RDSH |
| S5+ | 10.2 | S3 | PI | Berkowitz and Lifshitz, 1968 | RDSH |
| S6+ | ≤11.0 | S2 | PI | Berkowitz and Lifshitz, 1968 | RDSH |
| S6+ | 10.1 ± 0.3 | S2 | EI | Berkowitz and Chupka, 1964 | RDSH |
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]
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]
Hagemann, 1962
Hagemann, R.,
Determination de la chaleur de formation de S2O par spectrometrie de masse,
Compt. Rend., 1962, 255, 1102. [all data]
Richardson and Weinberger, 1975
Richardson, N.V.; Weinberger, P.,
The electronic structure of the S8 molecule,
J. Electron Spectrosc. Relat. Phenom., 1975, 6, 109. [all data]
Boschi and Schmidt, 1973
Boschi, R.; Schmidt, W.,
The photoelectron spectrum and structure of sulfur in the gas phase at 140 C,
Inorg. Nucl. Chem. Lett., 1973, 9, 643. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy 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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