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Updated: Jun 9, 2025

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Cyclic Ruthenium(II)-Halocarbon Complexes Derived from Ru(II)-Induced Cyclization of Homopropargylic Halopyridines:
Chi-Fung Yeung1,2, Sik-Him Tang1, Hau-Lam Shek1
1Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR.
Introducing a halide to alkyne substrates with ruthenium/osmium complexes unexpectedly formed novel haloquinolizine complexes. These complexes exhibit unique metal-halocarbon bonding and reactivity, impacting coordination chemistry designs.
Area of Science:
- Organometallic Chemistry
- Coordination Chemistry
- Synthetic Inorganic Chemistry
Background:
- Ruthenium (Ru) and Osmium (Os) complexes with bis(diphenylphosphino)methane (dppm) ligands are known to form metallacycles and metalated heterocycles.
- Previous studies focused on homopropargylic pyridines, yielding diverse metalated heterocyclic complexes.
Purpose of the Study:
- To investigate the effect of halide substitution on pyridyl alkyne substrates during activation by cis-[RuII/OsII(dppm)2Cl2] complexes.
- To characterize the structure and bonding of the resulting novel metalated complexes.
- To explore the reactivity of these new complexes, particularly the metal-halocarbon interactions.
Main Methods:
- Synthesis of novel haloquinolizine complexes via cycloisomerization reactions.
- Characterization using spectroscopic techniques and X-ray crystallography (implied).
- Investigation of reactivity, including nucleophilic substitution reactions.
Main Results:
- Formation of unprecedented Ru(II)/Os(II)-haloquinolizine complexes through a vinylidene pathway.
- These complexes feature unique κ²(X,C)-haloquinolizine chelates and five-membered M-X-C-N-C rings (M=Ru, Os; X=F, Cl, Br).
- Discovery of atypical metal-halocarbon (M-X-R) bonding interactions.
- Demonstration of halide susceptibility to substitution by oxygen in Ru(II) complexes, forming ruthenaoxazole derivatives.
Conclusions:
- Structural modification of alkyne substrates significantly alters complex formation and introduces novel bonding modes.
- The study highlights the importance of metal-halocarbon bonding in the design of coordination complexes and catalysts.
- The reactivity of the halide atom within the coordination sphere offers pathways for further functionalization.
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