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10:51
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
12.8K
Niobium tetrahalide complexes with neutral diphosphine ligands
Sophie L Benjamin1, Yao-Pang Chang2, Andrew L Hector2
1School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK.
Dalton Transactions (Cambridge, England : 2003)
|April 21, 2016
Summary
Niobium tetrachloride and tetrabromide react with diphosphine ligands to form diverse eight-coordinate complexes. Structural analysis reveals dodecahedral and square antiprismatic geometries, with implications for niobium chemistry.
Area of Science:
- Inorganic Chemistry
- Coordination Chemistry
- Organometallic Chemistry
Background:
- Niobium halides are versatile precursors in coordination chemistry.
- Diphosphine ligands offer tunable steric and electronic properties for metal complexation.
Purpose of the Study:
- To synthesize and characterize novel niobium(IV) complexes with diphosphine ligands.
- To investigate the structural diversity and bonding in these niobium complexes.
- To explore the reactivity and stability of niobium-diphosphine compounds.
Main Methods:
- Reaction of niobium tetrachloride (NbCl4) and niobium tetrabromide (NbBr4) with various diphosphine ligands.
- X-ray crystallography for structural determination of synthesized complexes.
- Spectroscopic techniques (IR, UV-Vis, NMR) and magnetic measurements for characterization.
- Microanalysis to confirm elemental composition.
Main Results:
- Synthesis of eight-coordinate [NbCl4(diphosphine)2] and [NbBr4(diphosphine)2] complexes.
- X-ray structures revealed dodecahedral and distorted square antiprismatic geometries.
- One-to-one complexes formed halide-bridged dimers with single Nb-Nb bonds.
- Characterization of niobium(V) complexes, including a dodecahedral cation and seven-coordinate niobium centers.
- Structure of niobium tetrabromide elucidated as a chain polymer with Nb-Nb bonds.
Conclusions:
- Diphosphine ligands can stabilize diverse coordination geometries around niobium(IV).
- The stoichiometry of the ligand dictates the formation of monomeric or dimeric niobium complexes.
- Niobium complexes exhibit varied reactivity, including hydrolysis, oxidation, and potential for Nb-Nb bond formation.
- Structural insights into niobium halide-diphosphine systems provide a foundation for further exploration.
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