131377 1,10-Phenanthroline, Merck

1,10-Phenanthroline is a white crystalline powder that acts as a bidentate ligand. It coordinates with metal ions through its two nitrogen atoms, forming highly stable Five-membered chelate rings. Its most famous application is the reaction with ferrous iron to form the intensely red-colored complex, known as ferroin. This property makes it the standard reagent for the colorimetric determination of iron and as a reversible redox indicator in titrimetry (e.g., cerimetry). Beyond analysis, it is used in coordination chemistry to study electron transfer and as a building block for supramolecular structures.

Advantages

• High Sensitivity: Capable of detecting trace amounts of iron even at very low concentrations.
• Stability: Forms exceptionally stable complexes with transition metals due to its rigid planar structure.
• Versatility: Serves as an excellent redox indicator with a sharp color change (from red to pale blue upon oxidation).
• Analytical Grade: This Sigma-Aldrich grade ensures high purity (≥99%) for reproducible quantitative analysis.
• Broad pH Range: The iron complex remains stable over a wide pH range (typically 2 to 9).

Technical specifications

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