Synthesis and Coordination Chemistry of Functionalised Phosphazanes
type: CreativeWork
description: This thesis focuses on the chemistry of novel phosphazane species derived from the chloro-phosphazanes [ClP(μ-NR)]$_2$ and their use as ligands and building blocks for macrocyclic compounds. The introduction (Chapter 1) surveys previous literature in the area, which is pertinent to the new studies. One of the most important issues is the various ways in which dimeric phosph(III)azanes can be employed as precursors for new ligands and in the design of new types of inorganic macrocycles. In Chapter 2 the synthesis of new chloro-dimers of the type [ClP(μ-NR)]$_2$ is described, which are the primary starting materials. Chapter 3 concerns the substitution at the chlorine atoms of [ClP(μ-NR)]$_2$ by LiSH to give a variety of sulfur-containing PV species [S=P(H)(μ-NR)]$_2$. The thermodynamic preference for the cis or trans isomers of the latter are explored by detailed NMR spectroscopic and DFT calculation investigations. Deprotonation of the $^t$Bu derivative [S=P(H)(μ-N$^t$Bu)]$_2$ using organometallic bases (Chapter 3) led to the isolation of s-block salts (Mg$^2+$, Na$^+$, K$^+$) of the P$^III$ dianion [S-P(μ-N$^t$Bu)]$^2_2-$. The Mg$^2+$ salt was found to form a mononuclear complex in the solid state whereas the Na$^+$ salt formed a large cage comprising eight dianions and 16 Na$^+$ ions built around a NaSH core. These s-block metal salts were shown to be useful transfer reagents for the dianion towards complexation with main group metals (e.g., Sn and Ge). Chapter 4 explores the oxidation of the P$^III$ dianions [S-P(μ-N$^t$Bu)]$^2_2-$ by chalcogens to give the more stable P$^V$ species [(E=)P$^V$(-S)(μ-N$^t$Bu)]$^2_2-$ (E = S, Se). The increase in stability and lower reducing ability of the P$^V$ dianion allowed the formation of complexes with transition and main group metals. Reaction of [(E=)PS(μ-N$^t$Bu)]$^2_2-$ with chloro-dimers [ClP(μ-NR)]$_2$ led to the formation of homo- and heteroleptic P$^III$-P$^V$ phosphazane macrocycles of the type [{S=PV(μ-N$^t$Bu)}2(u…
abstract: This thesis focuses on the chemistry of novel phosphazane species derived from the chloro-phosphazanes [ClP(μ-NR)]$_2$ and their use as ligands and building blocks for macrocyclic compounds. The introduction (Chapter 1) surveys previous literature in the area, which is pertinent to the new studies. One of the most important issues is the various ways in which dimeric phosph(III)azanes can be employed as precursors for new ligands and in the design of new types of inorganic macrocycles. In Chapter 2 the synthesis of new chloro-dimers of the type [ClP(μ-NR)]$_2$ is described, which are the primary starting materials. Chapter 3 concerns the substitution at the chlorine atoms of [ClP(μ-NR)]$_2$ by LiSH to give a variety of sulfur-containing PV species [S=P(H)(μ-NR)]$_2$. The thermodynamic preference for the cis or trans isomers of the latter are explored by detailed NMR spectroscopic and DFT calculation investigations. Deprotonation of the $^t$Bu derivative [S=P(H)(μ-N$^t$Bu)]$_2$ using organometallic bases (Chapter 3) led to the isolation of s-block salts (Mg$^2+$, Na$^+$, K$^+$) of the P$^III$ dianion [S-P(μ-N$^t$Bu)]$^2_2-$. The Mg$^2+$ salt was found to form a mononuclear complex in the solid state whereas the Na$^+$ salt formed a large cage comprising eight dianions and 16 Na$^+$ ions built around a NaSH core. These s-block metal salts were shown to be useful transfer reagents for the dianion towards complexation with main group metals (e.g., Sn and Ge). Chapter 4 explores the oxidation of the P$^III$ dianions [S-P(μ-N$^t$Bu)]$^2_2-$ by chalcogens to give the more stable P$^V$ species [(E=)P$^V$(-S)(μ-N$^t$Bu)]$^2_2-$ (E = S, Se). The increase in stability and lower reducing ability of the P$^V$ dianion allowed the formation of complexes with transition and main group metals. Reaction of [(E=)PS(μ-N$^t$Bu)]$^2_2-$ with chloro-dimers [ClP(μ-NR)]$_2$ led to the formation of homo- and heteroleptic P$^III$-P$^V$ phosphazane macrocycles of the type [{S=PV(μ-N$^t$Bu)}2(u…
author: Benson, Callum Giles Maxwell
language: en
keywords: Chemistry, Inorganic, Phosphazane, Macrocycle
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/a1e1f9c9-87f9-41fc-aa3e-7fc529d98264/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2016-10-27
date modified: 2026-07-22T22:24:32Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.9901