Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.583752
Title: Studies into the synthesis of primary phosphines for the preparation of macrocycles by template methods
Author: Reixach, Elisenda
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2006
Availability of Full Text:
Access from EThOS:
Access from Institution:
Abstract:
This thesis is focused in the synthesis of phosphine-based macrocycles by template methods. Furthermore, it explores some alternative methods for the synthesis of known and unknown polydentate primary phosphine compounds necessary for the preparation of new macrocycles. Following this new procedure the novel tripodal primary phosphine cis, cis-1,3,5-triphosphinomethylcyclohexane (2.15) has been prepared in good yields as well as the reported bis(2-phosphinoethyl)amine (PNP, 3.4). Mono-alkylation of 3.4 allowed the preparation of the asymmetric 2-(allylphosphino)-N-(2-phosphinoethyl)ethanamine ligand (3.16) in low yields. Whilst ligands 2.15 and 3.16 failed to form well-defined facially coordinated molybdenum(O) and chromium(O) complexes respectively, 3.4 formed octahedral complexes with Cr(0) and Fe(II) metals, {/ac-Cr(CO)3(PNP)}, 3.8 and {n5-C5H4(SiMe3)}Fe(PNP) PF6, 3.10. Different attempts have been made to cyclise the facially coordinated chromium complex 3.8, however all of them have failed. The synthesis of 3.8 and 3.10 has been confirmed by X-ray diffraction. The synthesis of a new Mn(I) 9-membered tribenzanulated I1 triphosphamacrocycle complex Mn(CO)3{(C6H4F)PC 6H4PHC6H4PHC6H4} OTf, 4.10 has been successfully synthesised by sequential introduction of 1,2-diphosphinobenzene and tris(2-fluorophenyl)phosphine on a manganese(I) complex and subsequent addition of /-BuOK. Alkylation of the two secondary phosphorus of 4.10 with Mel allowed the isolation of the more stable manganese complex II Mn(CO)3{(C6H4F)PC6H 4P(CH3)C6H4P(CH3)C 6H4} OTf/I 4.12. The liberation of the phosphine trioxide macrocycle, {(C6H4F)J>(0)C6H4P(0)(CH 3)C6H4(0)(CH3)C6H4 } 4.14 from the metal has been achieved using 4-methylmorpholine N-oxide in excess. In addition, the X-ray crystal structures of the non-cyclised precursor intermediate Mn(CO)3{(C6H4F)3P}{C 6H4(PH2)2-o} OTf 4.9 and the half cyclised intermediate (I Mn(CO)3{(C6H4F)2PC 6H4PHC6H4PH2} OTf 4.11 as well as the final macrocycle 4.12 have also been established.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.583752  DOI: Not available
Share: