Specialty Additives Available — Bulk Only

Tri-n-octylphosphine Oxide (TOPO)

TOPO
CAS 78-50-2 · Formula C24H51OP · MW 386.6 g/mol

A high-purity trialkylphosphine oxide for hydrometallurgical extraction and coordination chemistry. It is used as a metal-ion extractant in solvent-extraction processes and as a coordinating ligand in coordination and nanocrystal chemistry.

Safety Data Sheet
CAS Number
78-50-2
Formula
C24H51OP
Molecular Weight
386.6 g/mol
Material Family
Specialty Additives
At a Glance
Material Family
Specialty Additives
Record Type
Pure compound
Primary Role
Solvency · Chelation / Sequestration
Industries Served
Applications & Use Cases
  • Solvent extraction: Metal-ion extractant in hydrometallurgical separation
  • Coordination chemistry: Coordinating ligand for metal complexes
  • Nanomaterials: Coordinating solvent/ligand in nanocrystal and quantum-dot synthesis
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

Chemical Identity
CAS Number
78-50-2
Molecular Formula
C24H51OP
Molecular Weight
386.6 g/mol
IUPAC Name
1-dioctylphosphoryloctane
PubChem CID
InChI Key
ZMBHCYHQLYEYDV-UHFFFAOYSA-N
Synonyms & Trade Names
Trioctylphosphine oxide Tri-n-octylphosphine oxide Phosphine oxide, trioctyl- Cyanex 921 Hostarex PX 324 Trioctyl phosphine oxide 1-dioctylphosphoryloctane 1-(dioctylphosphoryl)octane C24H51OP trioctylphosphino-1-one TOPO
Full Description

Tri-n-octylphosphine oxide (CAS 78-50-2, C24H51OP) is a strongly coordinating trialkylphosphine oxide. It is used as a metal-ion extractant in solvent-extraction processes and as a coordinating ligand in coordination and nanocrystal chemistry.

Frequently Asked Questions

What is the use of trioctylphosphine oxide (TOPO)?

Tri-n-octylphosphine oxide (TOPO, CAS 78-50-2, C24H51OP) is a strongly coordinating trialkylphosphine oxide. It is used as a metal-ion extractant in hydrometallurgical solvent-extraction processes, as a coordinating ligand for metal complexes, and as a coordinating solvent/ligand in nanocrystal and quantum-dot synthesis. We supply it as a specialty additive in bulk.

Is TOPO the same as triphenylphosphine oxide (TPPO)?

No. TOPO is the tri-n-octyl (alkyl) phosphine oxide, C24H51OP (CAS 78-50-2), whereas TPPO is the triphenyl (aryl) analog. They differ in structure, solubility, and coordinating behavior and are not interchangeable; confirm CAS and identity on the CoA.

What is the solubility of trioctylphosphine oxide?

TOPO is a waxy solid that is soluble in many organic solvents and essentially insoluble in water, which suits its role in solvent extraction and as a coordinating solvent in nanocrystal synthesis. Lot-specific physical data is on the technical data sheet and SDS.

What is the CAS number and formula of TOPO?

Tri-n-octylphosphine oxide has CAS number 78-50-2 and molecular formula C24H51OP. Full identity and purity specifications are provided on the Certificate of Analysis with each lot.

What is the price of bulk TOPO and how is it supplied?

TOPO pricing is quote-based and depends on purity grade, volume, and packaging. It is supplied as a solid specialty additive. Submit a bulk quote request with your target volume and required purity for current pricing, CoA, and SDS.

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.