Dibromosilylene
- Formula: Br2Si
- Molecular weight: 187.893
- IUPAC Standard InChI: InChI=1S/Br2Si/c1-3-2
- IUPAC Standard InChIKey: KBDJQNUZLNUGDS-UHFFFAOYSA-N
- CAS Registry Number: 14877-32-8
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
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Gas phase thermochemistry data
Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, NIST Free Links, 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 |
|---|---|---|---|---|---|
| ΔfH°gas | -12.50 | kcal/mol | Review | Chase, 1998 | Data last reviewed in December, 1977 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 72.942 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in December, 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. - 6000. |
|---|---|
| A | 13.91660 |
| B | -0.027115 |
| C | -0.006987 |
| D | 0.007117 |
| E | -0.099080 |
| F | -16.98070 |
| G | 89.23470 |
| H | -12.50000 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in December, 1977 |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Vibrational and/or electronic energy levels, NIST Free Links, 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:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
B - John E. Bartmess
View reactions leading to Br2Si+ (ion structure unspecified)
Electron affinity determinations
| EA (eV) | Method | Reference | Comment |
|---|---|---|---|
| >1.7 | EIAE | Pabst, Margrave, et al., 1977 | From SiBr4; G2MP2 calculations indicate an EA of ca. 1.3 eV; B |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| ~8.5 | DER | Creasey, Lambert, et al., 1991 | LL |
| 12. ± 1. | EI | Farber and Srivastava, 1980 | LLK |
Vibrational and/or electronic energy levels
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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: Marilyn E. Jacox
State: A ?
| Energy (cm-1) |
Med. | Transition | λmin (nm) |
λmax (nm) |
References | ||
|---|---|---|---|---|---|---|---|
| Tx = 27600 | gas | A-X | 340 | 400 | Ruzsicska, Jodhan, et al., 1987 | ||
State: X
| Vib. sym. |
No. | Approximate type of mode |
cm-1 | Med. | Method | References | |
|---|---|---|---|---|---|---|---|
| a1 | 1 | Sym. stretch | 402.6 | s | Ar | IR | Maass, Hauge, et al., 1972 |
| b2 | 3 | Asym. stretch | 399.5 | vs | Ar | IR | Maass, Hauge, et al., 1972 |
Additional references: Jacox, 1994, page 101
Notes
| s | Strong |
| vs | Very strong |
| x | Energy separation between the band maximum of the excited electronic state and the v = 0 level of the ground state. |
References
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Vibrational and/or electronic energy levels, NIST Free Links, 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]
Pabst, Margrave, et al., 1977
Pabst, R.E.; Margrave, J.L.; Franklin, J.L.,
Electron impact studies of the tetrachlorides and tetrabromides of silicon and germanium,
Int. J. Mass Spectrom. Ion Phys., 1977, 25, 361. [all data]
Creasey, Lambert, et al., 1991
Creasey, J.C.; Lambert, I.R.; Tuckett, R.P.; Codling, K.; Leszek, J.F.; Hatherly, P.A.; Stankiewicz, M.,
Photoionization mass-spectrometric study of fragmentation of SiBr4 and GeBr4 in the range 400-1220 A,
J. Chem. Soc. Faraday Trans., 1991, 87, 3717. [all data]
Farber and Srivastava, 1980
Farber, M.; Srivastava, R.D.,
Mass spectrometric determination of the heats of formation of the silicon bromides SiBr(g), SiBr2(g), and SiBr3(g).,
High Temp. Sci., 1980, 12, 21. [all data]
Ruzsicska, Jodhan, et al., 1987
Ruzsicska, B.; Jodhan, A.; Safarik, I.; Strausz, O.P.; Bell, T.N.,
Flash photolysis of SiBr4: the UV spectrum of SiBr2,
Chem. Phys. Lett., 1987, 139, 1, 72, https://doi.org/10.1016/0009-2614(87)80153-7
. [all data]
Maass, Hauge, et al., 1972
Maass, G.; Hauge, R.H.; Margrave, J.L.,
The I.R. Spectra of Matrix-isolated SiBr2 and SiCl2,
Z. Anorg. Allg. Chem., 1972, 392, 3, 295, https://doi.org/10.1002/zaac.19723920314
. [all data]
Jacox, 1994
Jacox, M.E.,
Vibrational and electronic energy levels of polyatomic transient molecules, American Chemical Society, Washington, DC, 1994, 464. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Vibrational and/or electronic energy levels, NIST Free Links, References
- Symbols used in this document:
EA Electron affinity 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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