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Updated: Jul 27, 2025
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Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
14.0K
Photogenerated Ni(I)-Bipyridine Halide Complexes: Structure-Function Relationships for Competitive C(sp
David A Cagan1, Daniel Bím1, Brendon J McNicholas1
1Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States.
Inorganic Chemistry
|June 6, 2023
Summary
Researchers developed new nickel(I)-bipyridine halide complexes for photochemical reactions. Ligand substituents tune reactivity, enabling activation of challenging C(sp2)-Cl bonds via an SNAr mechanism, offering new photocatalytic possibilities.
Area of Science:
- Organometallic Chemistry
- Photocatalysis
- Synthetic Methodology
Background:
- Nickel complexes are crucial catalysts in organic synthesis.
- Understanding ligand effects on nickel reactivity is key for catalyst design.
- Activation of strong C-X bonds remains a significant challenge in catalysis.
Purpose of the Study:
- To photochemically generate and characterize a library of Ni(I)-bipyridine halide complexes.
- To investigate the structure-reactivity relationships governing oxidative addition and dimerization.
- To elucidate the mechanism of C(sp2)-Cl bond activation and the role of ligand substituents.
Main Methods:
- Photochemical synthesis of Ni(I)-bpy halide complexes.
- Reactivity benchmarking via competitive oxidative addition and dimerization assays.
- Dual Hammett and computational analysis to probe reaction mechanisms.
- Investigation of ligand substituent effects on electronic properties (Zeff).
Main Results:
- A library of Ni(I)(Rbpy)X complexes was successfully synthesized.
- Ligand substituents strongly influence reactivity, controlling oxidative addition vs. dimerization.
- C(sp2)-Cl bond activation proceeds via an SNAr-type mechanism, distinct from C(sp2)-Br/I activation.
- Substituent effects on effective nuclear charge (Zeff) modulate Ni(I) 3d orbital energies and reactivity.
Conclusions:
- Ligand design is a powerful tool to tune Ni(I) complex reactivity.
- Modulating Zeff provides a strategy to activate challenging C-X bonds.
- This work offers new avenues for developing efficient Ni-mediated photocatalytic cycles.
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