Related Experiment Video
Updated: Jul 10, 2026
08:46
Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)
Published on: November 22, 2016
Bifunctional diphosphorus Lewis acids from cyclodiphosphadiazanes
Reagan J Davidson1, Jan J Weigand, Neil Burford
1Department of Chemistry, Dalhousie University, Halifax, NS, Canada.
Chemical Communications (Cambridge, England)
|November 9, 2007
Summary
Researchers replaced triflate groups in a cyclodiphosphazane with DMAP or Me3P, forming novel dicationic complexes. These complexes act as bifunctional diphosphorus Lewis acceptors, expanding coordination chemistry possibilities.
Area of Science:
- Organophosphorus Chemistry
- Coordination Chemistry
- Supramolecular Chemistry
Background:
- Cyclodiphosphazanes are versatile phosphorus-nitrogen heterocyclic compounds.
- Triflate groups are excellent leaving groups, facilitating nucleophilic substitution reactions.
- Lewis acid-base interactions are fundamental in coordination chemistry.
Purpose of the Study:
- To investigate the reactivity of 1,3-ditriflato-2,4-bis(2,6-dimethylphenyl)cyclodiphospha-2,4-diazane.
- To synthesize novel dicationic complexes using DMAP and Me3P as nucleophiles.
- To characterize the resulting complexes as bifunctional diphosphorus Lewis acceptors.
Main Methods:
- Quantitative displacement reactions of triflate groups.
- Synthesis and isolation of dicationic complexes.
- Spectroscopic characterization (NMR, Mass Spectrometry) of the products.
Main Results:
- Successful displacement of triflate groups by 4-dimethylaminopyridine (DMAP) and trimethylphosphine (Me3P).
- Formation of stable dicationic complexes with the general formula [R2P(μ-NR')2PR2]2+.
- Demonstration of the dicationic complexes' ability to act as bifunctional diphosphorus Lewis acceptors.
Conclusions:
- The cyclodiphosphazane scaffold readily undergoes substitution reactions with strong nucleophiles.
- The synthesized dicationic complexes represent a new class of Lewis acidic phosphorus compounds.
- These findings open avenues for developing new catalysts and materials based on diphosphorus Lewis acceptors.
Related Concept Videos
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
02:33Lewis Acids and Bases
In 1923, G. N. Lewis proposed a generalized definition of acid-base behavior in which acids and bases are identified by their ability to accept or to donate a pair of electrons and form a coordinate covalent bond.
A coordinate covalent bond (or dative bond) occurs when one of the atoms in the bond provides both bonding electrons. For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. A coordinate covalent bond also results when...
A coordinate covalent bond (or dative bond) occurs when one of the atoms in the bond provides both bonding electrons. For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. A coordinate covalent bond also results when...
02:16Lewis Acids and Bases
This lesson delves into Lewis acids and bases in the context of the octet rule for electron-deficient compounds. Here, the concept is discussed, emphasizing the group 13 elements like boron or aluminium. Since group 13 elements possess three valence electrons, they form trivalent compounds with a sextet of electrons and a vacant orbital for the central atom. Consequently, these electron-deficient compounds accept electrons from other species to complete their octet in a chemical reaction. They...
01:24Diels–Alder Reaction: Characteristics of Dienophiles
In a Diels–Alder reaction, the diene is usually an electron-rich system and acts as a nucleophile, whereas the dienophile is electron-deficient and functions as an electrophile. Much like the diene, the nature of the dienophile significantly impacts the outcome of the reaction.
Characteristics of Dienophiles
Generally, the best dienophiles are alkenes containing electron-withdrawing substituents such as carbonyl, nitrile, and nitro groups. The feasibility of a Diels–Alder reaction depends on...
Characteristics of Dienophiles
Generally, the best dienophiles are alkenes containing electron-withdrawing substituents such as carbonyl, nitrile, and nitro groups. The feasibility of a Diels–Alder reaction depends on...
01:29Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
01:19Diazonium Group Substitution: –OH and –H
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.