Boron dihydride
- Formula: BH2
- Molecular weight: 12.827
- CAS Registry Number: 14452-64-3
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Gas phase thermochemistry data
Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, 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 | 200.83 | kJ/mol | Review | Chase, 1998 | Data last reviewed in December, 1964 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 180.19 | J/mol*K | Review | Chase, 1998 | Data last reviewed in December, 1964 |
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 (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.
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| Temperature (K) | 298. to 1300. | 1300. to 6000. |
|---|---|---|
| A | 27.96607 | 55.96728 |
| B | 29.19060 | 3.264763 |
| C | -6.409428 | -0.617010 |
| D | -0.659348 | 0.040532 |
| E | -0.183321 | -9.779724 |
| F | 190.6389 | 164.0161 |
| G | 204.5913 | 222.6980 |
| H | 200.8320 | 200.8320 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in December, 1964 | Data last reviewed in December, 1964 |
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:
B - John E. Bartmess
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
View reactions leading to H2B+ (ion structure unspecified)
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 9.8 ± 0.2 | EI | Fehlner and Koski, 1964 | RDSH |
De-protonation reactions
HB- + = H2B
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1629. ± 28. | kJ/mol | D-EA | Reid, 1993 | gas phase; B |
Vibrational and/or electronic energy levels
Go To: Top, Gas phase thermochemistry data, 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.
Data compiled by: Marilyn E. Jacox
State: A
| Energy (cm-1) |
Med. | Transition | λmin (nm) |
λmax (nm) |
References | ||
|---|---|---|---|---|---|---|---|
| To = 4194.1 | gas | A-X | 640 | 870 | Herzberg and Johns, 1967 | ||
| Vib. sym. |
No. | Approximate type of mode |
cm-1 | Med. | Method | References | |
|---|---|---|---|---|---|---|---|
| a1 | 2 | Bend | 953.6 | gas | AB | Herzberg and Johns, 1967 | |
Additional references: Jacox, 1994, page 17
Notes
| o | Energy separation between the v = 0 levels of the excited and electronic ground states. |
References
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Vibrational and/or electronic energy levels, 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]
Fehlner and Koski, 1964
Fehlner, T.P.; Koski, W.S.,
Direct detection of the borane molecule and the boryl radical by mass spectrometry,
J. Am. Chem. Soc., 1964, 86, 2733. [all data]
Reid, 1993
Reid, C.J.,
Electron Affinities of BH, B2, BC, and BN molecules determined using Charge Inversion Spectrometry,
Int. J. Mass Spectrom. Ion Proc., 1993, 127, 147, https://doi.org/10.1016/0168-1176(93)87087-9
. [all data]
Herzberg and Johns, 1967
Herzberg, G.; Johns, J.W.C.,
The Spectrum and Structure of the Free BHFormula Radical,
Proc. Roy. Soc. (London) A298, 1967, 298, 1453, 142, https://doi.org/10.1098/rspa.1967.0096
. [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
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- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) ΔfH°gas Enthalpy of formation of gas at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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