Bismuth dimer

Formula: Bi₂
Molecular weight: 417.96080
CAS Registry Number: 12187-12-1
Information on this page:
Other data available:
- Gas phase ion energetics data
Options:
- Switch to SI units

Constants of diatomic molecules

Data compiled by: Klaus P. Huber and Gerhard H. Herzberg

Data collected through May, 1976

Symbols used in the table of constants
Symbol	Meaning
State	electronic state and / or symmetry symbol
T_e	minimum electronic energy (cm^-1)
ω_e	vibrational constant – first term (cm^-1)
ω_ex_e	vibrational constant – second term (cm^-1)
ω_ey_e	vibrational constant – third term (cm^-1)
B_e	rotational constant in equilibrium position (cm^-1)
α_e	rotational constant – first term (cm^-1)
γ_e	rotation-vibration interaction constant (cm^-1)
D_e	centrifugal distortion constant (cm^-1)
β_e	rotational constant – first term, centrifugal force (cm^-1)
r_e	internuclear distance (Å)
Trans.	observed transition(s) corresponding to electronic state
ν₀₀	position of 0-0 band (units noted in table)

Diatomic constants for ²⁰⁹Bi₂
State	T_e	ω_e	ω_ex_e	ω_ey_e	B_e	α_e	γ_e	D_e	β_e	r_e	Trans.	ν₀₀
y	x+15746.3	94.7 H	5.2								y → x R	15741.4 H
y	↳Singh, Nair, et al., 1971
x	x	103.2 H	2.45
Fragments of several absorption systems in the region 44800 - 52900 cm^-1.
↳Almy and Sparks, 1933; Nakamura and Shidel, 1935; Topouzkhanian, Sibai, et al., 1974
D	(42228) 1	129 H	9.7								D ← (A) 1 R	24485 H
D	↳missing citation
Three diffuse absorption bands at 40115, 40275, 40467 cm^-1.
↳Almy and Sparks, 1933
State	T_e	ω_e	ω_ex_e	ω_ey_e	B_e	α_e	γ_e	D_e	β_e	r_e	Trans.	ν₀₀
C	36456	155.2 2 H	2.3 3								C ← X R	36447 H
C	↳missing citation; Nakamura and Shidel, 1935
I	33216.7	156.4 H	6.1								I → A V	15487.9 H
I	↳missing citation
H	[32657.1] 4										H → A V	14851.6 H
H	↳missing citation
Continuous absorption with maximum at 32000 cm^-1.
↳Almy and Sparks, 1933
State	T_e	ω_e	ω_ex_e	ω_ey_e	B_e	α_e	γ_e	D_e	β_e	r_e	Trans.	ν₀₀
G	(29609.0) 5	107.0 5 H	0.2								(G → A) 5 R	11857.0 H
G	↳missing citation
E	(26504.7)	(63.₅) 6	(8.5)		(0.01425) 6	(0.00015)					E → B	(21470.9) 7 (Z)
E	↳Gerber and Broida, 1976
A 0_u⁺	17739.3	132.49 H	0.302 8	-0.0021	0.01968 9 10	0.000053		11		2.863	A ↔ X R	17719.2 H
A 0_u⁺	↳missing citation; Nakamura and Shidel, 1935; Aslund, Barrow, et al., 1965; missing citation; Gerber and Broida, 1976
A'	(8000) 12	141.2	0.37	-0.0019
State	T_e	ω_e	ω_ex_e	ω_ey_e	B_e	α_e	γ_e	D_e	β_e	r_e	Trans.	ν₀₀
B	(5000) 12	127.0₅	0.29 13	-0.001	(0.01790)	(0.000046)
X ¹Σ_g⁺	0 12	172.71 H	0.341 14	-0.0018	[0.022781] 10	0.000055 15		[1.50E-09]		2.6596
X'	(-1500) 12	154.3	0.42

Notes

Contrary to the conclusion of Almy and Sparks Almy and Sparks, 1933 that the violet system involves low vibrational levels of A, Gerber and Broida Gerber and Broida, 1976 consider it more probable that the absorption originates in high vibrational levels (v" ~20) of X', thereby reducing to (T_e= 26000 cm^-1) Gerber and Broida, 1976. Additional unassigned diffuse absorption features in the region 22000 - 24000 cm^-1.

Nakamura and Shidel, 1935 give ω_e 146.0 Nakamura and Shidel, 1935, ω_ex_e = 0.50 Nakamura and Shidel, 1935. All bands except those with v'=1 are diffuse. Observed to v'=4. At shorter wavelengths are additional features probably belonging to C←X but not assigned by Almy and Sparks, 1933.

The value of ω_ex_e given by Almy and Sparks, 1933 is clearly 2ω_ex_e. The constants listed above take account of this correction.

Only v'=0.

Gerber et al. Gerber and Broida, 1976 have found very similar constants (ω_e = 105.6₈ Gerber and Broida, 1976, ω_ex_e = 0.63 Gerber and Broida, 1976) for the lower state of an unidentified transition in the laser photoluminescence spectrum and have tentatively identified this lower state with the upper state of Reddy and Ali's Reddy and Ali, 1970 G → A system. They suggest that the emission from G involves high vibrational levels (v" ~ 50) of X, rather than v=0,...,4 of A, and they estimate T_e ~ 20000 Gerber and Broida, 1976.

Constants derived from intensity data; see Gerber and Broida, 1976.

Recalculated from data in Gerber and Broida, 1976.

ω_ez_e = +0.000055 Reddy and Ali, 1970. Slightly different constants in Almy and Sparks, 1933, Gerber and Broida, 1976.

Extrapolated from B₈, B₉, B₁₁ Aslund, Barrow, et al., 1965.

RKR potential curves Rao and Lakshman, 1970, Gerber and Broida, 1976.

D₈ = 1.71E-9.

All four states give rise to long lower state progressions in the laser photoluminescence spectrum of Bi₂ Gerber and Broida, 1976. Their relative energies were estimated Gerber and Broida, 1976 from the temperature dependence of the photoluminescence intensities. The upper levels of the transitions, except those belonging to A and E, could not be identified.

missing note

ω_ez_e = +0.00001₀ Reddy and Ali, 1970. Slightly different constants in Almy and Sparks, 1933, Gerber and Broida, 1976.

From the laser photoluminescence spectrum Gerber and Broida, 1976, adjusted for best overall fit of observed with calculated intensities.

The state designations adopted in the Bi₂ table agree with those of Gerber and Broida, 1976. They are compared below with designations used elsewhere: <TABLE> <TR> <TD>This table, and Gerber and Broida, 1976:</TD> <TD> X' </TD> <TD> X </TD> <TD> B </TD> <TD> A' </TD> <TD> A </TD> <TD> E </TD> <TD> G </TD> <TD> H </TD> <TD> I </TD> <TD> C </TD> <TD> D </TD> </TR> <TR> <TD> Almy and Sparks, 1933 </TD> <TD></TD> <TD> A </TD> <TD></TD> <TD></TD> <TD> B </TD> <TD></TD> <TD></TD> <TD></TD> <TD></TD> <TD> C </TD> <TD> D </TD> </TR> <TR> <TD> Herzberg, 1950 </TD> <TD></TD> <TD> X </TD> <TD></TD> <TD></TD> <TD> B </TD> <TD></TD> <TD></TD> <TD></TD> <TD></TD> <TD> D </TD> <TD> E </TD> </TR> <TR> <TD> Aslund, Barrow, et al., 1965 </TD> <TD></TD> <TD> X </TD> <TD></TD> <TD></TD> <TD> A </TD> <TD></TD> <TD></TD> <TD></TD> <TD></TD> <TD></TD> <TD></TD> </TR> <TR> <TD> Rosen, 1970 </TD> <TD></TD> <TD> X </TD> <TD></TD> <TD></TD> <TD> A </TD> <TD></TD> <TD></TD> <TD></TD> <TD></TD> <TD> C </TD> <TD> D </TD> </TR> <TR> <TD> Reddy and Ali, 1970 </TD> <TD></TD> <TD> X </TD> <TD></TD> <TD></TD> <TD> A </TD> <TD></TD> <TD> G </TD> <TD> H </TD> <TD> I </TD> <TD> D </TD> <TD> E </TD> </TR> </TABLE>

Thermochemical value (mass-spectrom.) Kohl, Uy, et al., 1967, Rovner, Drowart, et al., 1967, calculated for a ¹Σ ground state and disregarding other low-lying states.

References

Go To: Top, Constants of diatomic molecules, Notes

Singh, Nair, et al., 1971
Singh, J.; Nair, K.P.R.; Rai, D.K., A new band system in the emission spectrum of diatomic bismuth, Spectrosc. Lett., 1971, 4, 313. [all data]

Almy and Sparks, 1933
Almy, G.M.; Sparks, F.M., The absorption spectrum of diatomic bismuth, Phys. Rev., 1933, 44, 365. [all data]

Nakamura and Shidel, 1935
Nakamura, G.; Shidel, T., 3. The band spectra of elements of the fifth group, Jpn. J. Phys., 1935, 10, 11. [all data]

Topouzkhanian, Sibai, et al., 1974
Topouzkhanian, A.; Sibai, A.M.; d'Incan, J., Observation et analyse vibrationnelle de nouveauz systemes de bandes d'absorption de molecules lourdes dans l'ultraviolet lointain Cas de Sb₂ et Bi₂, Z. Naturforsch. A, 1974, 29, 436. [all data]

Gerber and Broida, 1976
Gerber, G.; Broida, H.P., Electronic states and molecular constants of Bi₂, J. Chem. Phys., 1976, 64, 3423. [all data]

Aslund, Barrow, et al., 1965
Aslund, N.; Barrow, R.F.; Richards, W.G.; Travis, D.N., Rotational analysis of bands of the B-X system of Cu₂ and of the A-X system of Bi₂, Ark. Fys., 1965, 30, 171. [all data]

Reddy and Ali, 1970
Reddy, S.P.; Ali, M.K., The emission spectrum of diatomic bismuth, J. Mol. Spectrosc., 1970, 35, 285. [all data]

Rao and Lakshman, 1970
Rao, T.V.R.; Lakshman, S.V.J., True potential energy curves for the bands of the Bi₂ molecule, Indian J. Pure Appl. Phys., 1970, 8, 785. [all data]

Herzberg, 1950
Herzberg, G., Molecular spectra and molecular structure. I. Spectra of diatomic molecules, Pub. D. Van Nostrand Company, Inc., Princeton, New Jersey, 1950, 0. [all data]

Rosen, 1970
Rosen, B., International tables of selected constants. 17. Spectroscopic data relative to diatomic molecules, Pub. Pergamon Press, Oxford, 1970, 0. [all data]

Kohl, Uy, et al., 1967
Kohl, F.J.; Uy, O.M.; Carlson, K.D., Cross sections for electron-impact fragmentation and dissociation energies of the dimer and tetramer of bismuth, J. Chem. Phys., 1967, 47, 2667. [all data]

Rovner, Drowart, et al., 1967
Rovner, L.; Drowart, A.; Drowart, J., Mass spectrometric determination of dissociation energies of molecules Bi₂, Bi₃, Bi₄, and BiPb, Trans. Faraday Soc., 1967, 63, 2906. [all data]

Notes

Go To: Top, Constants of diatomic molecules, References

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
Customer support for NIST Standard Reference Data products.