Niobium Oxidation States
Reference covering niobium's oxidation states (+5 to −1), key compounds, electron configuration, and applications in superconductors and high-strength steel alloys.
Niobium is a Group 5 d-block metal that exhibits oxidation states from −1 to +5. The +5 state is dominant in ordinary chemistry — the d0 configuration achieved by losing all five valence electrons (4d4 5s1) confers maximum stability. Lower states (+4, +3, +2) are well-characterised in halides and oxides but are progressively more air-sensitive. Negative oxidation states appear only in organometallic carbonyl complexes.
| State | Stability | d-electron count | Example compounds |
|---|---|---|---|
| +5 | Dominant | d⁰ | Nb₂O₅, NbF₅, NbCl₅, NbOCl₃, LiNbO₃ |
| +4 | Stable | d¹ | NbO₂, NbCl₄, NbBr₄, NbI₄ |
| +3 | Moderate | d² | NbCl₃, Nb₂O₃, NbBr₃, Nb(η⁵-Cp)Cl₃ |
| +2 | Reducing | d³ | NbO, NbI₂, cluster halides Nb₆X₁₄ |
| +1 | Rare | d⁴ | Organoniobium clusters; not in simple salts |
| 0 | Elemental | d⁵ (approx.) | Nb metal; NbTi and Nb₃Sn alloys (superconductors) |
| −1 | Very rare | d⁶ | Nb(CO)₆⁻ anion in carbonylate complexes |
IE1 = 652.1 kJ/mol | IE2 = 1380 kJ/mol | IE3 = 2416 kJ/mol | IE4 = 3700 kJ/mol | IE5 = 4877 kJ/mol
No single ionization step shows the extreme jump seen in main-group elements, consistent with the graded stability of +1 through +5 in transition metals.
Summary
Reference covering niobium's oxidation states (+5 to −1), key compounds, electron configuration, and applications in superconductors and high-strength steel alloys.
How it works
- Click a tab — Oxidation States, Compounds, Electron Config, or Physical Props — to explore each topic.
- The Oxidation States panel lists every known state from −1 to +5 with stability and typical compound examples.
- The Compounds panel gives a full table of niobium compounds, their formulas, Nb oxidation state, and applications.
- The Electron Config panel shows the orbital diagram and ionization steps from Nb to Nb5+.
- The Physical Props panel provides atomic mass, melting point, density, and other material data at a glance.
- Click any monospace table cell to copy its value to the clipboard.
Use cases
- Students studying d-block or Group 5 transition metal chemistry.
- Engineers selecting niobium alloys for aerospace or nuclear reactor components.
- Materials scientists designing niobium-based superconducting magnets or RF cavities.
- Researchers working with niobium oxide catalysts or capacitor-grade niobium.
- Metallurgists specifying HSLA steel compositions that use niobium microalloying.
- Chemistry teachers preparing lessons on variable oxidation states in transition metals.