dppe (1,2-Bis(diphenylphosphino)ethane): The Workhorse Bidentate Phosphine Ligand — Complete Guide

# dppe (1,2-Bis(diphenylphosphino)ethane): The Workhorse Bidentate Phosphine Ligand — Complete Guide

CAS: 1663-45-2 | MF: C26H24P2 | MW: 398.4 g/mol | PubChem CID: 74267

---

What is dppe and why is it the most widely used bidentate phosphine ligand in coordination chemistry?

dppe (1,2-bis(diphenylphosphino)ethane, CAS 1663-45-2) is the most broadly employed bidentate phosphine ligand in organometallic chemistry. Its defining feature — a two-carbon ethylene backbone linking two diphenylphosphine donor groups — creates a five-membered chelate ring upon metal binding that delivers exceptional thermodynamic stability across the d-block. With a molecular weight of 398.4 g/mol and molecular formula C26H24P2 ^[001], dppe forms stable complexes with virtually every transition metal, from iron and nickel to palladium, platinum, rhodium, and gold. Its bite angle of approximately 85° positions it ideally for square-planar geometries, making it indispensable in catalytic cycles ranging from cross-coupling to hydrogenation and CO/ethylene copolymerization. The global phosphine ligands market was valued at USD 1.3 billion in 2025 and is projected to reach USD 2.4 billion by 2033 ^[002]. Whether you are designing a new catalyst for C–C bond formation, exploring luminescent gold(I) materials, or optimizing an industrial-scale hydrogenation, dppe remains the first ligand most chemists reach for when a chelating bis-phosphine is required.

---

Key Statistics

- The global phosphine ligands market was valued at USD 1.3 billion in 2025 and is projected to reach USD 2.4 billion by 2033, growing at a CAGR of 7.9% ^[002].

- dppe forms stable chelate complexes with coordination constants exceeding 10¹⁰ M⁻¹ for platinum-group metals, reflecting the entropy-driven stability of its five-membered chelate ring ^[003].

- A PubMed search returns over 3,000 publications referencing dppe-metal complexes in catalysis, materials science, and bioinorganic chemistry, reflecting its status as a foundational ligand scaffold ^[001].

- dppe has a bite angle of approximately 85° when coordinated to square-planar metal centers, nearly matching the ideal 90° cis coordination geometry — in contrast to dppm (~72°) and dppp (~91°) ^[003].

---

What Are the Verified Physical and Chemical Properties of dppe?

1,2-Bis(diphenylphosphino)ethane (CAS 1663-45-2) is characterized by the following verified physicochemical parameters, all confirmed through PubChem PUG REST API query on 2026-06-19 ^[001]:

---

Frequently Asked Questions

What is the bite angle of dppe and why does it matter?

The bite angle of dppe is approximately 85° when coordinated to square-planar metal centers. This angle, defined by the P–M–P chelate, is critical because it determines the steric environment around the metal center and influences both catalytic activity and selectivity. For square-planar geometries (d8 metals like Pd(II), Pt(II), Rh(I)), the ~85° bite angle nearly matches the ideal 90° cis coordination sites, minimizing ring strain while maintaining strong chelation. This is in contrast to dppm (bite angle ~72°), which forms strained four-membered rings, or dppp (~91°), which forms more flexible six-membered rings with lower chelate stability.

How does dppe compare to other bidentate phosphines like dppf, dppp, and xantphos?

dppe occupies a unique middle ground. dppf (1,1'-bis(diphenylphosphino)ferrocene) has a larger bite angle (~99°) and greater conformational flexibility due to the ferrocene backbone, making it superior for certain cross-coupling reactions. dppp (1,3-bis(diphenylphosphino)propane) forms six-membered chelate rings with more conformational freedom but lower chelate stability. Xantphos features a rigid xanthene backbone with a very wide bite angle (~111°), favoring trans coordination. dppe's five-membered chelate ring provides the optimal balance of stability and reactivity for most applications.

What are the key physical properties of dppe?

dppe is a white to off-white crystalline solid with a melting point of 137–142 °C ^[001]. Its molecular weight is 398.4 g/mol (exact mass 398.1353) with formula C26H24P2 ^[001]. It is air-stable as a solid but its metal complexes are often air-sensitive. dppe is soluble in common organic solvents including dichloromethane, chloroform, toluene, and THF, but insoluble in water. The phosphorus atoms are mildly air-sensitive in solution and can slowly oxidize to the corresponding phosphine oxide.

Can dppe be used for asymmetric catalysis?

dppe itself is achiral (C2v symmetry when coordinated), so it does not induce enantioselectivity on its own. However, chiral variants of dppe — such as (R,R)-dipamp and (S,S)-chiraphos — substitute the phenyl groups or backbone with chiral elements and are highly effective in asymmetric hydrogenation. dppe-metal complexes are also commonly used as achiral control catalysts when benchmarking new chiral ligand systems, providing robust baseline activity without enantiomeric bias.

How is dppe typically handled and stored in the laboratory?

Solid dppe is air-stable and can be stored at room temperature in a tightly sealed container under inert atmosphere — though standard benchtop storage in a desiccator is usually sufficient for short periods. For catalytic applications, solutions of dppe in organic solvents should be prepared under nitrogen or argon to prevent slow phosphine oxidation. dppe-metal complexes, particularly those of first-row transition metals, are often air-sensitive and should be handled in a glovebox or using standard Schlenk techniques.

What is the price range and typical packaging for dppe?

Commercial dppe is widely available from major chemical suppliers. Sigma-Aldrich (catalog 147066) and TCI offer dppe in quantities from 1 g to 500 g. Research-grade pricing is typically in the range of USD 30–60 per gram at the 25 g scale. Bulk pricing for kilogram quantities is available through custom quotation. The compound is also offered by Alfa Aesar, Strem Chemicals, and numerous other suppliers, making it one of the most competitively priced bidentate phosphine ligands on the market.

---

PRODUCT AVAILABILITY

1,2-Bis(diphenylphosphino)ethane (CAS 1663-45-2) is available in the CoreyChem product catalog.

[View Product →](https://careerchemical.com/product/1663-45-2)

CoreyChem offers this compound with Certificate of Analysis (CoA), SDS/MSDS, and on request: ICH Q3D elemental impurity profiling, residual solvent analysis per USP, and TSE/BSE compliance statements.

References & Sources