What Is 8-Hydroxy-5-nitroquinoline?

8-Hydroxy-5-nitroquinoline is a heterocyclic organic compound belonging to the hydroxyquinoline family. It is structurally derived from 8-hydroxyquinoline (oxine) by the introduction of a nitro group (–NO₂) at the 5-position of the quinoline ring. This substitution modifies the electronic properties of the molecule, influencing its metal-binding affinity, solubility, and biological activity compared with the parent compound.

The molecule contains two key donor atoms — the phenolic oxygen at position 8 and the ring nitrogen at position 1 — enabling it to act as a bidentate chelating ligand capable of forming stable five-membered chelate rings with a wide range of transition and post-transition metal ions.

Aladdin Scientific supplies 8-Hydroxy-5-nitroquinoline under SKU H423833. Researchers seeking related structural analogs may also refer to SKU H107536 as a reference compound.

Chemical Properties and Structure

The quinoline scaffold of 8-Hydroxy-5-nitroquinoline provides an aromatic bicyclic framework consisting of a benzene ring fused to a pyridine ring. The 8-hydroxy group is positioned ortho to the ring nitrogen, which is the geometric prerequisite for bidentate chelation. The electron-withdrawing nitro group at position 5 reduces the electron density of the aromatic system relative to unsubstituted 8-hydroxyquinoline, which can affect the pKa of the hydroxyl group and thereby shift metal-complex stability constants.

Key physicochemical characteristics include moderate solubility in polar organic solvents such as ethanol, methanol, dimethyl sulfoxide (DMSO), and dimethylformamide (DMF), with limited solubility in water at neutral pH. The compound is a solid at room temperature. Exact melting point, molecular weight, and purity specifications should be confirmed from the Certificate of Analysis (CoA) provided with each lot of H423833.

Applications in Research

Coordination and Inorganic Chemistry: 8-Hydroxy-5-nitroquinoline is primarily used as a chelating ligand for the preparation of metal complexes. Its ability to coordinate metals through the N,O-donor set makes it valuable for synthesizing complexes with copper, zinc, nickel, cobalt, iron, and other metals. These complexes are studied for their structural diversity, magnetic properties, and catalytic potential.

Analytical Chemistry: Hydroxyquinoline derivatives have a history of use as analytical reagents for the colorimetric or gravimetric determination of metal ions. The nitro-substituted variant may offer altered spectral properties useful in detection workflows, though specific validated methods for H423833 should be confirmed in peer-reviewed literature.

Biological and Pharmacological Research: 8-Hydroxyquinoline derivatives, including nitro-substituted analogs, have been investigated for antimicrobial, antifungal, and antiprotozoal activities. The metal-complexing ability of the compound is often implicated in its mechanism of biological action. Researchers exploring structure–activity relationships in this compound class may find H423833 a useful tool compound.

Handling, Storage, and Safety Considerations

As with all laboratory reagents, 8-Hydroxy-5-nitroquinoline should be handled in accordance with good laboratory practice. Researchers should consult the Safety Data Sheet (SDS) supplied by Aladdin Scientific for H423833 before use. General precautions applicable to nitroaromatic and hydroxyquinoline compounds include:

• Use appropriate personal protective equipment (PPE) including gloves, lab coat, and eye protection.
• Handle in a well-ventilated area or fume hood to minimize inhalation exposure to dust or vapors.
• Avoid contact with skin and eyes.
• Store in a cool, dry, well-ventilated location away from incompatible materials, heat sources, and direct sunlight.
• Dispose of waste in accordance with local institutional and regulatory requirements for organic chemical waste.

Exact GHS hazard classifications, first-aid measures, and disposal codes should be taken from the current lot-specific SDS available from Aladdin Scientific.

Ordering and Availability

8-Hydroxy-5-nitroquinoline is available from Aladdin Scientific under SKU H423833. Researchers requiring a related reference compound may also consult SKU H107536 as noted in the product documentation.

To place an order, request a quotation, or obtain a Certificate of Analysis (CoA) or Safety Data Sheet (SDS) for a specific lot, please contact Aladdin Scientific through the official website or your regional sales representative. Bulk quantities and custom packaging may be available upon request; lead times and pricing will depend on stock availability.

For questions about purity specifications, analytical data, or technical suitability of H423833 for a specific application, the Aladdin Scientific technical support team can provide guidance.