1,2-Bis(diphenylphosphino)ethane nickel(II) chloride
[CAS# 14647-23-5]

Identification

• Classification: Chemical reagent >> Organic reagent >> Phosphine ligand
• Name: 1,2-Bis(diphenylphosphino)ethane nickel(II) chloride
• Molecular Formula: C₂₆H₂₄Cl₂NiP₂
• Molecular Weight: 528.02
• CAS Registry Number: 14647-23-5
• EC Number: 629-489-4
• SMILES: C1=CC=C(C=C1)P(CCP(C2=CC=CC=C2)C3=CC=CC=C3)C4=CC=CC=C4.[Cl-].[Cl-].[Ni+2]

Properties

• Melting point: 263-265 °C
• Water solubility: insoluble

Safety Data

• Hazard Symbols: GHS07;GHS08 Danger
• Risk Statements: H302-H312-H315-H317-H319-H332-H334-H335-H350-H351
• Safety Statements: P203-P233-P260-P261-P264-P264+P265-P270-P271-P272-P280-P284-P301+P317-P302+P352-P304+P340-P305+P351+P338-P317-P318-P319-P321-P330-P332+P317-P333+P317-P337+P317-P342+P316-P362+P364-P403-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Respiratory sensitization	Resp. Sens.	1	H334
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - single exposure	STOT SE	3	H335
Carcinogenicity	Carc.	1B	H350
Skin sensitization	Skin Sens.	1	H317
Carcinogenicity	Carc.	1A	H350
Reproductive toxicity	Repr.	1B	H360
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Acute toxicity	Acute Tox.	3	H331
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Carcinogenicity	Carc.	2	H351
Acute toxicity	Acute Tox.	3	H301

Discovery and Applications

1,2-Bis(diphenylphosphino)ethane nickel(II) chloride, often referred to as Ni(dppp)Cl₂, is a prominent example of a nickel-based complex with significant applications in organometallic chemistry and catalysis. This compound, featuring a nickel(II) center coordinated by two diphenylphosphine groups and chloride ligands, has been instrumental in advancing various chemical transformations.

The discovery of 1,2-Bis(diphenylphosphino)ethane nickel(II) chloride is rooted in the broader exploration of transition metal complexes for catalytic purposes. The ligand, 1,2-Bis(diphenylphosphino)ethane (dppp), was designed to provide enhanced stability and reactivity to metal centers through its bidentate phosphine functionality. This design allows for effective coordination with the nickel center, leading to the formation of a stable, yet reactive, nickel(II) complex.

This complex has become a valuable tool in a range of catalytic processes. Its primary applications include facilitating cross-coupling reactions, which are fundamental in the synthesis of complex organic molecules. These reactions involve the formation of carbon-carbon bonds and are widely used in pharmaceutical and materials chemistry. Ni(dppp)Cl₂ is particularly noted for its role in Suzuki-Miyaura and Negishi coupling reactions, where it helps in the coupling of aryl and vinyl halides with organoboron or organozinc reagents.

The effectiveness of Ni(dppp)Cl₂ in these reactions is attributed to the electronic and steric properties imparted by the dppp ligand. The phosphine groups provide significant electron-donating effects, which stabilize the nickel center and facilitate its interaction with substrates. The resulting complex can promote reactions with high efficiency, offering a viable alternative to palladium-based catalysts in some cases.

In addition to its role in cross-coupling reactions, 1,2-Bis(diphenylphosphino)ethane nickel(II) chloride has been employed in other types of catalytic transformations, including hydrogenation and polymerization reactions. Its versatility makes it a valuable component in the toolkit of synthetic chemists seeking to explore new reaction pathways or improve existing processes.

The ongoing research into nickel-based catalysts, including Ni(dppp)Cl₂, reflects a broader trend towards developing more cost-effective and environmentally benign alternatives to precious metal catalysts. Nickel, being more abundant and less expensive than palladium or platinum, offers a promising route for sustainable chemistry.

Overall, 1,2-Bis(diphenylphosphino)ethane nickel(II) chloride represents a significant advancement in the field of organometallic chemistry. Its discovery and subsequent applications illustrate the impact of transition metal complexes on modern chemical synthesis, highlighting the importance of innovative ligand design and catalytic optimization.

References

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