Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.785477
Title: New tunable metal phosphine complexes with polymerisation capabilities
Author: Cao, Bo
ISNI:       0000 0004 7970 9871
Awarding Body: Loughborough University
Current Institution: Loughborough University
Date of Award: 2017
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Abstract:
A new series of alkene based functionalised phosphorus ligands bearing PCN backbones were synthesised using a phosphorus Mannich condensation reaction. They were further studied by coordination to various transition metal centres. Following a procedure well established within our research group, two phosphorus ligands were obtained using [P(CH₂OH)₄]Cl (THPC). THPC was reacted with 'ortho' and 'para' anilines to give the phosphonium salts [P{CH₂N(H)R}₄]Cl [R = o-{C(Me)=CH₂}C₆H₄, p-(CH=CH₂)C₆H₄]. They were reacted with tBuOK to produce P{CH₂N(H)R}₃ phosphines [R = o-{C(Me)=CH₂}C₆H₄, p-(CH=CH₂)C₆H₄]. In addition, new phosphine ligands were synthesised by reacting alkene containing amines (2-isopropenylaniline, 4-vinylaniline, 2-aminoethyl methacrylate hydrochloride) with one or two equivalents of hydroxymethyldiphenylphosphine, Ph₂PCH₂OH. These ligands were coordinated with a number of transition metals [Pd(II), Pt(II), Rh(III), Rh(I), Ru(II), Au(I)]. Coordination chemistry of P{CH₂N(H)R}₃ (R = p-{CH=CH₂}C₆H₄) was unsuccessful as the product changes colour and becomes insoluble in both sunlight and under a dark environment. The family of alkyne based functionalised phosphorus ligands was extended by reacting alkyne containing amines (1-ethynylcyclohexylamine, 2-ethynylaniline, 3-ethynylaniline, 4-ethynylaniline) with Ph₂PCH₂OH. 1-Ethynylcyclohexylamine and 2-ethynylaniline were able to react with only one equivalent of Ph₂PCH₂OH while 3-ethynylaniline and 4-ethynylaniline reacted with two equivalents of Ph₂PCH₂OH. 2-ethynylaniline and 4-ethynylaniline were synthesised following literature procedures however they were purified using different procedures. These ligands were treated with transition metals [Pd(II), Pt(II), Rh(III), Rh(I), Ru(II)] to study their coordination properties. In all cases, the ligands bond through the P-donor ligands. Another five potentially polymerisable phosphorus ligands were synthesised to enlarge the family of polymerisable monomers. They were synthesised from various amines [dopamine, 3-amino-2-azepanone, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylamine, 4-(2-aminoethyl)morpholine] and appropriate amounts of Ph₂PCH₂OH. 3-Amino-2-azepanone was synthesised following the literature procedure by reacting L-lysine methyl ester dihydrochloride with NaOH. The study of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylamine and 4-(2-aminoethyl)morpholine) reacting with Ph₂PCH₂OH has been successful while their coordination chemistries were only studied briefly. These phosphine ligands were subsequently reacted with transition metals [Pd(II), Pt(II), Rh(III), Rh(I), Ru(II)]. All these phosphine ligands and their coordinated monomers were characterised by ³¹P{¹H} NMR, IR spectroscopy and MS. Two of the compounds were further confirmed by single crystal X-ray crystallography. A preliminary study of polymerisation work was conducted on four of the alkene based metal supported monomers [PdCl₂L, L = Ph₂PCH₂N(R)CH₂PPh₂, R = 4-vinylaniline; RhCl₂(Cp*)L, L = Ph₂PCH₂NH(R), R = o-{C(Me)=CH₂}C₆H₄, [RhCl₂(Cp*)]₂L, L = Ph₂PCH₂N(R)CH₂PPh₂, R = p-(CH=CH₂)C₆H₄, RhCl(cod)L, L= Ph₂PCH₂NH(R), R = o-{C(Me)=CH₂}C₆H₄]. The products were insoluble in regular solvents such as MeOH, EtOH, and NMR solvents CDCl₃, (CD₃)₂SO, D₂O which is very much different from the literature and were characterised using IR spectroscopy, MS and elemental analysis. The disappearance of the C=C double bond indicated a possible reason for successfully preliminary study of polymerisation.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.785477  DOI: Not available
Keywords: Chemical Sciences not elsewhere classified
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