Beryllium monofluoride


Gas phase thermochemistry data

Go To: Top, Gas phase ion energetics data, 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
Δfgas-40.600kcal/molReviewChase, 1998Data last reviewed in December, 1971
Quantity Value Units Method Reference Comment
gas,1 bar49.175cal/mol*KReviewChase, 1998Data 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 (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

View table.

Temperature (K) 298. to 1100.1100. to 6000.
A 4.6296208.743010
B 8.9605690.227576
C -7.204711-0.041374
D 2.1301800.004116
E 0.037527-0.381616
F -42.19319-44.21530
G 52.6193158.26991
H -40.59990-40.59990
ReferenceChase, 1998Chase, 1998
Comment Data last reviewed in December, 1971 Data last reviewed in December, 1971

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, 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.

Data compiled as indicated in comments:
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to BeF+ (ion structure unspecified)

Ionization energy determinations

IE (eV) Method Reference Comment
9.3 ± 1.0EIFarber and Srivastava, 1974LLK
9.1 ± 0.5EIHildenbrand and Murad, 1966RDSH

Constants of diatomic molecules

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: Klaus P. Huber and Gerhard H. Herzberg

Data collected through April, 1976

Symbols used in the table of constants
SymbolMeaning
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)
Diatomic constants for 9Be19F
StateTeωeωexeωeyeBeαeγeDeβereTrans.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
StateTeωeωexeωeyeBeαeγeDeβereTrans.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

1A0=+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.
2Slightly different constants in Tatevskii, Tunitskii, et al., 1958.
3The 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.
4D1 = 8.26E-6.
5J'=1/2 (average of F1 and {F2}) relative to N"=0.
6Mass-spectrometric values Hildenbrand and Murad, 1966, Farber and Srivastava, 1974.

References

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

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]

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]

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]


Notes

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Constants of diatomic molecules, References