niobium

• Formula: Nb
• Molecular weight: 92.90638
• IUPAC Standard InChI: InChI=1S/Nb Copy

  
• IUPAC Standard InChIKey: GUCVJGMIXFAOAE-UHFFFAOYSA-N Copy
• 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:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • Ion clustering data
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
• 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
• Options:
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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = 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
    C_p = heat capacity (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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Gas phase ion energetics data

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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)

Electron affinity determinations

Ionization energy determinations

Ion clustering data

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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. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

 +  = ( • )

By formula: Nb⁺ + Nb = (Nb⁺ • Nb)

Enthalpy of reaction

( • ) +  = ( • 2)

By formula: (Nb⁺ • Nb) + Nb = (Nb⁺ • 2Nb)

Enthalpy of reaction

( • 2) +  = ( • 3)

By formula: (Nb⁺ • 2Nb) + Nb = (Nb⁺ • 3Nb)

Enthalpy of reaction

( • 3) +  = ( • 4)

By formula: (Nb⁺ • 3Nb) + Nb = (Nb⁺ • 4Nb)

Enthalpy of reaction

( • 4) +  = ( • 5)

By formula: (Nb⁺ • 4Nb) + Nb = (Nb⁺ • 5Nb)

Enthalpy of reaction

( • 5) +  = ( • 6)

By formula: (Nb⁺ • 5Nb) + Nb = (Nb⁺ • 6Nb)

Enthalpy of reaction

( • 6) +  = ( • 7)

By formula: (Nb⁺ • 6Nb) + Nb = (Nb⁺ • 7Nb)

Enthalpy of reaction

( • 7) +  = ( • 8)

By formula: (Nb⁺ • 7Nb) + Nb = (Nb⁺ • 8Nb)

Enthalpy of reaction

( • 8) +  = ( • 9)

By formula: (Nb⁺ • 8Nb) + Nb = (Nb⁺ • 9Nb)

Enthalpy of reaction

( • 9) +  = ( • 10)

By formula: (Nb⁺ • 9Nb) + Nb = (Nb⁺ • 10Nb)

Enthalpy of reaction

References

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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]

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]

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]

Notes

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• 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)
  T	Temperature
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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