Trihexylphosphine

Updated: 2026-09-09

Overview

Trihexylphosphine (THP) is a tertiary phosphine compound belonging to the organophosphorus family. Structurally, it consists of a phosphorus atom bonded to three hexyl groups. This compound is primarily utilized in coordination chemistry as a ligand due to its strong electron-donating capability and steric bulk. In industrial and research settings, THP is particularly valued for its ability to stabilize transition metal complexes in catalytic processes. Its hydrophobic nature makes it suitable for reactions in non-polar solvents, distinguishing it from more hydrophilic phosphine ligands.

Physical and Chemical Properties

As a liquid at room temperature, trihexylphosphine exhibits moderate volatility with a characteristic phosphine odor. Its molecular weight of 286.48 g/mol and density of approximately 0.83 g/cm³ make it lighter than water. The compound's boiling point under reduced pressure (0.1 mmHg) ranges between 120-125°C. Chemically, THP demonstrates typical phosphine behavior - it acts as a σ-donor ligand with weak π-acceptor properties. The hexyl groups provide steric protection to the phosphorus center, enhancing stability against oxidation compared to shorter-chain alkylphosphines. However, it remains air-sensitive and gradually oxidizes when exposed to atmospheric oxygen.

Main Applications

In catalysis, THP serves as a crucial ligand for transition metals like rhodium, palladium, and platinum. It significantly improves reaction rates and selectivity in hydroformylation and hydrogenation processes. The compound's electron-rich nature facilitates oxidative addition steps in cross-coupling reactions. Beyond homogeneous catalysis, trihexylphosphine finds application in nanomaterials synthesis. It effectively stabilizes metal nanoparticles during their formation, preventing aggregation. This property is exploited in producing quantum dots and other nanostructured materials with controlled size distributions.

Safety and Storage

As an organophosphorus compound, THP requires careful handling due to its flammability and potential health effects. Appropriate personal protective equipment (gloves, goggles, lab coat) should be worn, and operations should be conducted in a fume hood. The compound may cause skin and eye irritation upon contact. For long-term storage, trihexylphosphine must be kept in tightly sealed containers under an inert atmosphere (nitrogen or argon) at cool temperatures (2-8°C). Moisture should be strictly excluded to prevent decomposition. Commercially available THP is typically packaged in septum-sealed bottles or ampoules to maintain purity.

B2B Procurement Guide

When procuring trihexylphosphine industrially, buyers should clearly specify required purity levels (typically 95-99%), packaging format (ampoules, bottles, or bulk containers), and desired quantity. Technical specifications should include moisture and oxygen content limits, especially for sensitive applications. Lead times may vary significantly between suppliers, particularly for customized quantities or purity grades. Some manufacturers offer analytical certificates (CoA) with each batch. For large-scale purchases, consider evaluating multiple suppliers for competitive pricing and minimum order quantities (MOQs).