Related Experiment Video
Updated: May 20, 2026

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)
Published on: November 22, 2016
Terminal phosphinidene formation via tantalaziridine complexes
Matthew A Rankin1, Christopher C Cummins
1Department of Chemistry, Massachusetts Institute of Technology, Room 6-435, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA.
Bulky anilide ligands support the preparation of terminal, 4-coordinate phosphinidenes of tantalum (Ta). This synthesis involves metallaziridine phosphanide complexes in a novel reaction sequence.
Area of Science:
- Organometallic chemistry
- Main group chemistry
Background:
- Phosphinidenes are reactive intermediates crucial for synthesizing novel phosphorus-containing compounds.
- Tantalum complexes offer unique electronic and steric properties for stabilizing reactive species.
Purpose of the Study:
- To synthesize and characterize terminal, 4-coordinate phosphinidenes of tantalum.
- To explore the utility of bulky anilide ligands in stabilizing low-coordinate main group elements.
Main Methods:
- Reaction of tantalum precursors with phosphide sources in the presence of bulky anilide ligands.
- Characterization using spectroscopic techniques (NMR, X-ray crystallography).
Main Results:
- Successful isolation of terminal, 4-coordinate tantalum phosphinidenes.
- Structural elucidation revealing a unique bonding environment around the tantalum center.
- The reaction proceeds through metallaziridine phosphanide intermediates.
Conclusions:
- The bulky anilide ligands effectively stabilize the reactive terminal phosphinidene species.
- This work expands the known reactivity of tantalum and provides a new route to phosphinidene complexes.
Related Concept Videos
Ziegler–Natta Chain-Growth Polymerization: Overview
Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism
The reaction begins with the nucleophilic addition between a phosphorus ylide and the carbonyl compound. Due to its carbanionic character, phosphorus ylide acts as a strong nucleophile and attacks the electrophilic carbonyl group. This generates a charge-separated dipolar intermediate called betaine. The negatively charged oxygen atom and...
α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Diazonium Group Substitution: –OH and –H

