Hafnium monoxide

Formula: HfO
Molecular weight: 194.49
IUPAC Standard InChI: InChI=1S/Hf.O/q+2;-2
IUPAC Standard InChIKey: SONXPDDOCAOTOE-UHFFFAOYSA-N
CAS Registry Number: 12029-22-0
Chemical structure:
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Gas phase ion energetics data

Go To: Top, Constants of diatomic molecules, References, Notes

Data compiled as indicated in comments:
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

Ionization energy determinations

IE (eV)	Method	Reference	Comment
7.6 ± 0.1	EI	Rauh and Ackermann, 1974	LLK

Constants of diatomic molecules

Go To: Top, Gas phase ion energetics data, References, Notes

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

Data collected through January, 1975

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 ¹⁸⁰Hf¹⁶O
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
J					[0.3719] 1 2					[1.756₇]	J → x₃ 1 R	22655.82 Z
J	↳missing citation; Weltner and McLeod, 1965; Edvinsson and Nylen, 1971
H					[0.3699] 1 2					[1.761₄]	H → x₂ 1 R	21239.87 Z
H	↳missing citation; Edvinsson and Nylen, 1971
C	x₁ + 19719.3	852.₅ H^Q	4.1		[0.3696] 1			[3.0E-7]		[1.762₁]	C → x₁ 1 R	19682.94 Z
C	↳missing citation; Edvinsson and Nylen, 1971
x₃		(945) 3	(5)		[0.3788] 1			[2.6E-07]		[1.740₆]
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
x₂					[0.3781] 1			[2.6E-7]		[1.742₂]
x₁	x₁	925.₀ H^Q	3.5		[0.3776] 1			[2.8E-7]		[1.743₃]
G ¹Σ⁽⁺⁾	30090.0	[852.29] Z	(3.7₁)		0.370106	0.002071		[2.764E-7] 4		1.76090₄	G ↔ X 5 R	30032.71 Z
G ¹Σ⁽⁺⁾	↳missing citation; Weltner and McLeod, 1965; Edvinsson and Nylen, 1971
F ¹Σ⁽⁺⁾	27413.59	849.40 Z	3.67		0.36563	0.00188		2.702E-7	2.3E-09	1.7716₅	F ↔ X 5 R	27351.14 Z
F ¹Σ⁽⁺⁾	↳missing citation; Weltner and McLeod, 1965; missing citation
E ¹Π	25230.94	866.93 Z 6	3.68		0.3692₈ 7 8	0.00198		2.69E-7		1.7636	E ↔ X 5 R	25177.25 6 Z
	↳missing citation; Weltner and McLeod, 1965; Edvinsson and Nylen, 1971; Wentink and Spindler, 1972
					0.3686₈ 9 8	0.00197		2.67E-7			E ↔ X 5 R	25177.25 6 Z
	↳missing citation; Weltner and McLeod, 1965; Edvinsson and Nylen, 1971; Wentink and Spindler, 1972
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
D ¹Π	23554.41	872.60 Z 6	3.31		0.3691₂ 9 8	0.00182		2.624E-7	3.2E-09	1.7642	D ↔ X 5 R	23503.65 6 Z
	↳missing citation; Weltner and McLeod, 1965; missing citation; Wentink and Spindler, 1972
					0.3683₇ 7 8	0.001800		2.631E-7	1.9E-09		D ↔ X 5 R	23503.65 6 Z
	↳missing citation; Weltner and McLeod, 1965; missing citation; Wentink and Spindler, 1972
B ¹Π 10	17562.22	907.01 Z 6	3.38		0.37806₀ 9	0.001852		2.63E-7		1.7429	B ↔ X 5 R	17528.65 6 Z
	↳missing citation; Weltner and McLeod, 1965; Edvinsson, 1966; Edvinsson and Nylen, 1971; Wentink and Spindler, 1972
					0.37753₇ 7	0.001848		2.618E-7	9E-10		B ↔ X 5 R	17528.65 6 Z
	↳missing citation; Weltner and McLeod, 1965; Edvinsson, 1966; Edvinsson and Nylen, 1971; Wentink and Spindler, 1972
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
A ¹Σ⁽⁺⁾ 10	16616.92	914.24 Z	3.38		0.377985	0.001827		2.587E-7	1.6E-09	1.74245₄	A ↔ X 5 R	16586.96 Z
A ¹Σ⁽⁺⁾ 10	↳missing citation; Weltner and McLeod, 1965; Edvinsson and Nylen, 1971; Wentink and Spindler, 1972
X ¹Σ⁽⁺⁾	0	974.09 Z	3.228		0.386537	0.001724		2.438E-7	6E-10	1.72307₁	11

Notes

P, Q, and R branches. No Λ-type doubling observed. The three systems are probably subsystems of a triplet - triplet transition, possibly ³Φ-³Δ (see Edvinsson, 1971).

v=0 perturbed by state of smaller B value.

From the fluorescence spectrum of HfO in a Ne matrix Weltner and McLeod, 1965.

D₁ = 3.73E-7, perturbed.

Absorption spectra of HfO in solid inert gas matrices; see Weltner and McLeod, 1965.

These band origins do not conform to the usual convention adopted in these tables. Subtract B'_v in order to obtain zero lines.

f levels.

Perturbations between D and E.

e levels.

Possibly ³Π₀₊ and ³Π₁; see Edvinsson, 1971.

IR spectrum of HfO trapped in Ne matrix Weltner and McLeod, 1965.

Thermochemical value (mass-spectrom. Ackermann and Rauh, 1974). See also Panish and Reif, 1963.

Electron impact appearance potential Rauh and Ackermann, 1974.

References

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

Rauh and Ackermann, 1974
Rauh, E.G.; Ackermann, R.J., First ionization potentials of some refractory oxide vapors, J. Chem. Phys., 1974, 60, 1396. [all data]

Weltner and McLeod, 1965
Weltner, W., Jr.; McLeod, D., Jr., Spectroscopy of titanium, zirconium, and hafnium oxides in neon and argon matrices at 4 and 20°K, J. Phys. Chem., 1965, 69, 3488. [all data]

Edvinsson and Nylen, 1971
Edvinsson, G.; Nylen, Ch., On the band spectrum of HfO, Phys. Scr., 1971, 3, 261. [all data]

Wentink and Spindler, 1972
Wentink, T., Jr.; Spindler, R.J., Jr., The isoelectronic series ScF through ThO-I notes on the band spectra of TiO, HfO and ThO, J. Quant. Spectrosc. Radiat. Transfer, 1972, 12, 1569. [all data]

Edvinsson, 1966
Edvinsson, G., On the bandspectrum of hafnium oxide, Die Naturwissenschaften, 1966, 53, 177. [all data]

Edvinsson, 1971
Edvinsson, Dissertation. USIP Report 71-09, Stockholm, 1971, 1. [all data]

Ackermann and Rauh, 1974
Ackermann, R.J.; Rauh, E.G., Thermodynamic properties of ZrO (g) and HfO (g); a critical examination of isomolecular oxygen-exchange reactions, J. Chem. Phys., 1974, 60, 2266. [all data]

Panish and Reif, 1963
Panish, M.B.; Reif, L., Thermodynamics of the vaporization of Hf and HfO₂: dissociation energy of HfO, J. Chem. Phys., 1963, 38, 253. [all data]

Notes

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Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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