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Boron


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
Deltafgas829.69kJ/molReviewChase, 1998Data last reviewed in March, 1979
Quantity Value Units Method Reference Comment
gas,1 bar202.07J/mol*KReviewChase, 1998Data last reviewed in March, 1979

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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View table.

Temperature (K) 298. - 800.800. - 6000.
A -5.56568243.33243
B 150.5307-3.618461
C -170.66700.949371
D 66.18586-0.067489
E 0.506419-0.352579
F 827.7333814.3738
G 160.3058250.2693
H 829.6872829.6872
ReferenceChase, 1998Chase, 1998
Comment Data last reviewed in March, 1979 Data last reviewed in March, 1979

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 by: John E. Bartmess

View reactions leading to B2+ (ion structure unspecified)

Electron affinity determinations

EA (eV) Reference Comment
>1.30 ± 0.40Reid, 1993EA "probably 41.5 kcal/mol.

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 September, 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 11B2
StateTeomegaeomegaexeomegaeyeBealphaegammaeDebetaereTrans.nu00
A 3Sigmau- 30573.4 937.4 Z 2.6  1.160 0.011    1.625 A lrarrow X R 30518.10 Z
missing citation; Nicholls, Fraser, et al., 1959; Graham and Weltner, 1976
X 3Sigmag- 0 1051.3 Z 9.35  1.212 0.014    1.590  

Notes

1Thermochemical value (mass-spectrom.); from Verhaegen and Drowart, 1962, but using the higher value from Stull and Prophet, 1971 for the heat of sublimation of boron.
2Experimental evidence Graham and Weltner, 1976 supports a 3Sigma ground state; theoretical calculations Bender and Davidson, 1967 predict a 5Sigmau- state at approximately 1100 cm-1 below the lowest state of 3Sigmag- symmetry.

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]

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]

Nicholls, Fraser, et al., 1959
Nicholls, R.W.; Fraser, P.A.; Jarmain, W.R., Transition probability parameters of molecular spectra arising from combustion processes, Combust. Flame, 1959, 3, 13. [all data]

Graham and Weltner, 1976
Graham; Weltner, Private communication cited in Huber and Herzberg, 1979, 1976, 65. [all data]

Verhaegen and Drowart, 1962
Verhaegen, G.; Drowart, J., Mass spectrometric determination of the heat of sublimation of boron and of the dissociation energy of B2, J. Chem. Phys., 1962, 37, 1367. [all data]

Stull and Prophet, 1971
Stull, D.R.; Prophet, H., JANAF Thermochemical Tables. Second Edition, Office of SRD (NSRDS-NBS 37), Washington, D.C., 1971, 0. [all data]

Bender and Davidson, 1967
Bender, C.F.; Davidson, E.R., Electronic structure of the B2 molecule, J. Chem. Phys., 1967, 46, 3313. [all data]

Huber and Herzberg, 1979
Huber, K.P.; Herzberg, G., Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules, Van Nostrand Reinhold Company, New York, 1979, 716. [all data]


Notes

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