Beryllium monofluoride
- Formula: BeF
- Molecular weight: 28.010585
- IUPAC Standard InChI: InChI=1S/Be.FH/h;1H/q+1;/p-1
- IUPAC Standard InChIKey: ROPFUFXLORQKEY-UHFFFAOYSA-M
- CAS Registry Number: 13597-96-1
- Chemical structure:
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Gas phase thermochemistry data
Go To: Top, Constants of diatomic molecules, 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 | -169.87 | kJ/mol | Review | Chase, 1998 | Data last reviewed in December, 1971 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 205.75 | J/mol*K | Review | Chase, 1998 | Data last reviewed in December, 1971 |
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 1100. | 1100. to 6000. |
|---|---|---|
| A | 19.37033 | 36.58075 |
| B | 37.49102 | 0.952178 |
| C | -30.14451 | -0.173111 |
| D | 8.912674 | 0.017222 |
| E | 0.157015 | -1.596682 |
| F | -176.5363 | -184.9968 |
| G | 220.1592 | 243.8013 |
| H | -169.8700 | -169.8700 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in December, 1971 | Data last reviewed in December, 1971 |
Constants of diatomic molecules
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 by: Klaus P. Huber and Gerhard H. Herzberg
Data collected through April, 1976
| Symbol | Meaning |
|---|---|
| State | electronic state and / or symmetry symbol |
| Te | minimum electronic energy (cm-1) |
| ωe | vibrational constant – first term (cm-1) |
| ωexe | vibrational constant – second term (cm-1) |
| ωeye | vibrational constant – third term (cm-1) |
| Be | rotational constant in equilibrium position (cm-1) |
| αe | rotational constant – first term (cm-1) |
| γe | rotation-vibration interaction constant (cm-1) |
| De | centrifugal distortion constant (cm-1) |
| βe | rotational constant – first term, centrifugal force (cm-1) |
| re | internuclear distance (Å) |
| Trans. | observed transition(s) corresponding to electronic state |
| ν00 | position of 0-0 band (units noted in table) |
| State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R shaded double-headed emission bands in the region 62900 - 64100 and 65800 - 66700 cm-1. | ||||||||||||
| ↳Novikov and Gurvich, 1967 | ||||||||||||
| C 2Σ+ | 50364.0 | 1419.7 H | 9.9 | 1.570 | 0.014 | 1.325 | C → A V | 17253.7 | ||||
| ↳Rao and Rao, 1965 | ||||||||||||
| C → X V | 50440.86 Z | |||||||||||
| ↳missing citation | ||||||||||||
| B 2Σ+ | 49563.9 | 1350.8 H | 12.6 | [1.547] | [1.335] | B → X V | 49605.6 Z | |||||
| ↳missing citation | ||||||||||||
| State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
| A 2Πr | 33233.7 1 | [1154.67] Z | 8.78 2 HQ | 1.42024 3 | 0.0175 | [8.40E-06] 4 | 1.3935 | A ↔ X R | 33187.13 5 Z | |||
| ↳missing citation; missing citation; Mulliken, 1931; Fowler, 1941; Tatevskii, Tunitskii, et al., 1958; Walker and Barrow, 1969 | ||||||||||||
| X 2Σ+ | 0 | [1247.36] Z | 9.12 2 HQ | 1.48893 | 0.0176 | 0.00000828 | 1.3610 | |||||
Notes
| 1 | A0=+21.82, A1=+21.93; slight J dependence. A negative value of A has been ruled out by the calculations of Walker and Richards, 1970. |
| 2 | Slightly different constants in Tatevskii, Tunitskii, et al., 1958. |
| 3 | The Λ-type doubling in the 1/2 and 3/2 components Walker and Barrow, 1969 does not follow the "pure precession" pattern for a regular 2Π state. An earlier explanation Walker and Richards, 1967 of this "anomaly" has since been revised Walker and Richards, 1970. |
| 4 | D1 = 8.26E-6. |
| 5 | J'=1/2 (average of F1 and {F2}) relative to N"=0. |
| 6 | Mass-spectrometric values Hildenbrand and Murad, 1966, Farber and Srivastava, 1974. |
References
Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, 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]
Novikov and Gurvich, 1967
Novikov, M.M.; Gurvich, L.V.,
The emission spectrum of BeF in the vacuum ultraviolet,
Opt. Spectrosc. Engl. Transl., 1967, 23, 173, In original 323. [all data]
Rao and Rao, 1965
Rao, K.M.; Rao, P.T.,
A new electronic transition in the BeF molecule,
Indian J. Pure Appl. Phys., 1965, 3, 177. [all data]
Mulliken, 1931
Mulliken, R.S.,
Note on the interpretation of the BeF bands,
Phys. Rev., 1931, 00, 836. [all data]
Fowler, 1941
Fowler, C.A., Jr.,
New absorption spectra of the alkaline earth fluorides,
Phys. Rev., 1941, 59, 645. [all data]
Tatevskii, Tunitskii, et al., 1958
Tatevskii, V.M.; Tunitskii, L.N.; Novikov, M.M.,
Vibration constant and dissociation energy of the BeF molecule,
Opt. Spektrosk., 1958, 5, 520. [all data]
Walker and Barrow, 1969
Walker, T.E.H.; Barrow, R.F.,
The A2Π-X2Σ+ system of BeF,
J. Phys. B:, 1969, 2, 102. [all data]
Walker and Richards, 1970
Walker, T.E.H.; Richards, W.G.,
The assignment of molecular orbital configurations on the basis of λ-type doubling,
J. Phys., 1970, 3, 271. [all data]
Walker and Richards, 1967
Walker, T.E.H.; Richards, W.G.,
The nature of the first excited electronic state in BeF,
Proc. Phys. Soc. London, 1967, 92, 285. [all data]
Hildenbrand and Murad, 1966
Hildenbrand, D.L.; Murad, E.,
Mass-spectrometric determination of the dissociation energy of beryllium monofluoride,
J. Chem. Phys., 1966, 44, 1524. [all data]
Farber and Srivastava, 1974
Farber, M.; Srivastava, R.D.,
Dissociation energies of BeF and BeCl and the heat of formation of BeClF,
J. Chem. Soc. Faraday Trans. 1, 1974, 70, 1581. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, References
- 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 - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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