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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
Pnictides as symmetrically bridging ligands in novel neutral complexes
1Institut fur Anorganische Chemie, Universitat Karlsruhe, Germany. mascheer@achibm6.chemie.uni-karlsruhe.de
Chemistry (Weinheim an Der Bergstrasse, Germany)
|April 29, 2000
Summary
Novel neutral pnictido-bridged tungsten complexes were synthesized. These paramagnetic complexes feature a linear structure with two tungsten-"tren" units bound to a central pnictido atom.
Area of Science:
- Organometallic Chemistry
- Coordination Chemistry
- Inorganic Synthesis
Background:
- Tungsten complexes with tris(2-aminoethyl)amine (tren) based ligands are of interest for their unique reactivity.
- Pnictido ligands (P, As, Sb) can bridge metal centers, leading to novel structural motifs.
Purpose of the Study:
- To synthesize and characterize novel neutral pnictido-bridged tungsten complexes.
- To investigate the structural and electronic properties of these new compounds.
- To explore the reactivity of tungsten-tren complexes with alkali metal pnictides.
Main Methods:
- Synthesis of tungsten-chlorido precursor complexes [LWCl] (3).
- Reaction with lithium pnictido reagents LiE(SiMe3)2 (E = P, As, Sb) to form pnictido-bridged complexes (5-7).
- Characterization using 31P NMR spectroscopy, paramagnetic susceptibility, and X-ray diffraction analysis.
- Synthesis of a side product complex [[N(CH2CH2NNp)3]W2(mu, eta 1: eta 1-N2)] (4) using dinitrogen as inert gas.
Main Results:
- Novel neutral pnictido-bridged tungsten complexes [LW=E=WL] (5-7) were successfully synthesized.
- 31P NMR studies ruled out terminal pnictido intermediates.
- Complexes 5-7 are paramagnetic and exhibit a linear structure with a staggered conformation of tungsten-'tren' units around the central pnictido atom.
- A side product, complex 4, featuring a hydrazido(4-) ligand bridged by two tungsten-'tren' moieties, was also formed.
Conclusions:
- The reaction provides a viable route to neutral pnictido-bridged tungsten complexes.
- The structural analysis reveals a unique linear arrangement of the metal centers and the bridging pnictogen atom.
- The formation of the hydrazido complex highlights the potential for dinitrogen activation under specific synthetic conditions.
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