niobium
- Formula: Nb
- Molecular weight: 92.90638
- IUPAC Standard InChI: InChI=1S/Nb
- IUPAC Standard InChIKey: GUCVJGMIXFAOAE-UHFFFAOYSA-N
- CAS Registry Number: 7440-03-1
- Chemical structure:
This structure is also available as a 2d Mol file - Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- NIST Atomic Spectra Database - Lines Holdings (on physics web site)
- NIST Atomic Spectra Database - Levels Holdings (on physics web site)
- NIST Atomic Spectra Database - Ground states and ionization energies (on physics web site)
- Gas Phase Kinetics Database
- X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, Reaction 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.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | 175.20 | kcal/mol | Review | Chase, 1998 | Data last reviewed in December, 1973 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 44.524 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in December, 1973 |
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.
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| Temperature (K) | 5131. to 6000. |
|---|---|
| A | -3498.327 |
| B | 1228.910 |
| C | -161.4106 |
| D | 7.539436 |
| E | 11390.30 |
| F | 10163.38 |
| G | 1480.418 |
| H | 175.2000 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in December, 1973 |
Condensed phase thermochemistry data
Go To: Top, Gas phase thermochemistry data, Reaction 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.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°liquid | 7.087 | kcal/mol | Review | Chase, 1998 | Data last reviewed in December, 1973 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°liquid,1 bar | 11.30 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in December, 1973 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°solid | 8.717 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in December, 1973 |
Liquid 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.
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| Temperature (K) | 2750. to 5130.824 |
|---|---|
| A | 8.000001 |
| B | 0.000001 |
| C | -1.163347×10-8 |
| D | -1.085402×10-8 |
| E | 0.000014 |
| F | 2.835995 |
| G | 18.34025 |
| H | 7.085732 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in December, 1973 |
Solid 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.
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| Temperature (K) | 298. to 2750. |
|---|---|
| A | 5.261544 |
| B | 2.363327 |
| C | -1.350032 |
| D | 0.420576 |
| E | 0.005220 |
| F | -1.644573 |
| G | 14.46558 |
| H | 0.000000 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in December, 1973 |
Reaction thermochemistry data
Go To: Top, Gas phase thermochemistry data, Condensed 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: Michael M. Meot-Ner (Mautner) and Sharon G. Lias
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
+
= (
•
)
By formula: Nb+ + Nb = (Nb+ • Nb)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 136. | kcal/mol | CID | Loh, Lian, et al., 1988 | gas phase; approximate value |
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 136.0 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( • 9
) +
= (
• 10
)
By formula: (Nb+ • 9Nb) + Nb = (Nb+ • 10Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 143.4 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( • 2
) +
= (
• 3
)
By formula: (Nb+ • 2Nb) + Nb = (Nb+ • 3Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 141.0 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( • 3
) +
= (
• 4
)
By formula: (Nb+ • 3Nb) + Nb = (Nb+ • 4Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 133.1 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( • 4
) +
= (
• 5
)
By formula: (Nb+ • 4Nb) + Nb = (Nb+ • 5Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 135.8 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( • 5
) +
= (
• 6
)
By formula: (Nb+ • 5Nb) + Nb = (Nb+ • 6Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 155.4 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( • 6
) +
= (
• 7
)
By formula: (Nb+ • 6Nb) + Nb = (Nb+ • 7Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 141.5 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( • 7
) +
= (
• 8
)
By formula: (Nb+ • 7Nb) + Nb = (Nb+ • 8Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 138.2 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( • 8
) +
= (
• 9
)
By formula: (Nb+ • 8Nb) + Nb = (Nb+ • 9Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 144.4 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
( •
) +
= (
• 2
)
By formula: (Nb+ • Nb) + Nb = (Nb+ • 2Nb)
Enthalpy of reaction
| ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 117.1 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction 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 evaluated as indicated in comments:
L - Sharon G. Lias
Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess
View reactions leading to Nb+ (ion structure unspecified)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| IE (evaluated) | 6.75885 ± 0.00004 | eV | N/A | N/A | L |
Electron affinity determinations
| EA (eV) | Method | Reference | Comment |
|---|---|---|---|
| 0.894 ± 0.025 | LPES | Feigerle, Corderman, et al., 1981 | B |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 6.75885 | EVAL | Lide, 1992 | LL |
| 6.75885 ± 0.00004 | LS | Rayner, Mitchell, et al., 1987 | LBLHLM |
| 6.61 ± 0.05 | EI | Rauh and Ackermann, 1979 | LLK |
| 10.1 ± 1.0 | EI | Gupta and Gingerich, 1978 | LLK |
| 6.88 | S | Moore, 1970 | RDSH |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, 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]
Loh, Lian, et al., 1988
Loh, S.K.; Lian, L.; Hales, D.A.; Armentrout, P.B.,
Collision - Induced Dissociation Processes of Nb4+ and Fe4+: Fission vs Evaporation,
J. Chem. Phys., 1988, 89, 1, 610, https://doi.org/10.1063/1.455455
. [all data]
Armentrout and Kickel, 1994
Armentrout, P.B.; Kickel, B.L.,
Gas Phase Thermochemistry of Transition Metal Ligand Systems: Reassessment of Values and Periodic Trends, in Organometallic Ion Chemistry, B. S. Freiser, ed, 1994. [all data]
Feigerle, Corderman, et al., 1981
Feigerle, C.S.; Corderman, R.R.; Bobashev, S.V.; Lineberger, W.C.,
Binding Energies and Structure of Transition Metal Negative Ions,
J. Chem. Phys., 1981, 74, 3, 1580, https://doi.org/10.1063/1.441289
. [all data]
Lide, 1992
Lide, D.R. (Editor),
Ionization potentials of atoms and atomic ions
in Handbook of Chem. and Phys., 1992, 10-211. [all data]
Rayner, Mitchell, et al., 1987
Rayner, D.M.; Mitchell, S.A.; Bourne, O.L.; Hackett, P.A.,
First-ionization potential of niobium and molybdenum by double-resonance, field-ionization spectroscopy,
J. Opt. Soc. Am. B, 1987, 4, 900. [all data]
Rauh and Ackermann, 1979
Rauh, E.G.; Ackermann, R.J.,
The first ionization potentials of the transition metals,
J. Chem. Phys., 1979, 70, 1004. [all data]
Gupta and Gingerich, 1978
Gupta, S.K.; Gingerich, K.A.,
Mass spectrometric observation dissociation energy of the gaseous molecule MoNb,
J. Chem. Phys., 1978, 69, 4318. [all data]
Moore, 1970
Moore, C.E.,
Ionization potentials and ionization limits derived from the analyses of optical spectra,
Natl. Stand. Ref. Data Ser., (U.S. Natl. Bur. Stand.), 1970, 34, 1. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
EA Electron affinity IE (evaluated) Recommended ionization energy S°gas,1 bar Entropy of gas at standard conditions (1 bar) S°liquid,1 bar Entropy of liquid at standard conditions (1 bar) S°solid Entropy of solid at standard conditions T Temperature ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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