Self-assembled monolayers of metal complexes attached to gold electrodes
In this thesis, ten different ligands were designed and synthesized in such a way as to provide metal containing SAMs. The metal binding sites of these ligands are derivatives of the tripodal ligand tris(2-pyridylmethyl)amine (TPA) and the tridentate amine bis(2-pyridylmethyl)amine (BPA), which have...
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ndltd-bl.uk-oai-ethos.bl.uk-6423112015-12-03T03:34:41ZSelf-assembled monolayers of metal complexes attached to gold electrodesCalatayud Sanz, Maria Pilar2009In this thesis, ten different ligands were designed and synthesized in such a way as to provide metal containing SAMs. The metal binding sites of these ligands are derivatives of the tripodal ligand tris(2-pyridylmethyl)amine (TPA) and the tridentate amine bis(2-pyridylmethyl)amine (BPA), which have good molecular recognition properties in solution. As interface separating the electrode from the metal binding site and gold anchor group we have chosen a thiophenyl, thioethyl and thioctic acid groups. Electrochemical studies with [Fe(CN)<sub>6</sub>]<sup>3-/4-</sup> as redox probe in solution were carried out on SAMs of the TPA thioctic acid derivative L4 and its complexes Cu-L4, Zn-L4 and Fe-L4. Monolayers containing redox active Cu(II/I) ions accelerated the electron-transfer reaction (<i>k</i><sub>app </sub>= 2.78 x 10<sup>-2</sup> cm/s) more than those containing Zn(II) (<i>k</i><sub>app</sub> = 1.51 x 10<sup>-4</sup> cm/s) and Fe(II) (<i>k</i><sub>app </sub>= 1.40 x 10<sup>-3</sup> cm/s) ions. This is consistent with a mechanism for electron-transfer in which the Cu ions exit in different coordination environments and with different redox potentials, and are rapidly undergoing interconversion. The ability of this system to facilitate the electron-transfer process to the redox probe was used to develop a new cyanide sensor. Addition of cyanide ions increases the blocking behaviour of the SAM, suggesting the elimination of Cu from the SAM to form [Cu(CN)<sub>n</sub>]<sup>(n-1)- </sup>complexes. The cyanide detection limit was found to be 1 nM. Electrodes modified with the binucleating ligand 2,6-bis[bis(2-pyridylmethyl)amino-methyl]phenol thioctic acid derivative (bearing two BPA arms) L7 were also investigated. Metal containing SAMs can influence the electron-transfer process through the SAM to a solution containing a redox probe. This property can be used to develop new anion sensors in aqueous system.541.37University of Edinburghhttp://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642311http://hdl.handle.net/1842/10851Electronic Thesis or Dissertation |
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541.37 Calatayud Sanz, Maria Pilar Self-assembled monolayers of metal complexes attached to gold electrodes |
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In this thesis, ten different ligands were designed and synthesized in such a way as to provide metal containing SAMs. The metal binding sites of these ligands are derivatives of the tripodal ligand tris(2-pyridylmethyl)amine (TPA) and the tridentate amine bis(2-pyridylmethyl)amine (BPA), which have good molecular recognition properties in solution. As interface separating the electrode from the metal binding site and gold anchor group we have chosen a thiophenyl, thioethyl and thioctic acid groups. Electrochemical studies with [Fe(CN)<sub>6</sub>]<sup>3-/4-</sup> as redox probe in solution were carried out on SAMs of the TPA thioctic acid derivative L4 and its complexes Cu-L4, Zn-L4 and Fe-L4. Monolayers containing redox active Cu(II/I) ions accelerated the electron-transfer reaction (<i>k</i><sub>app </sub>= 2.78 x 10<sup>-2</sup> cm/s) more than those containing Zn(II) (<i>k</i><sub>app</sub> = 1.51 x 10<sup>-4</sup> cm/s) and Fe(II) (<i>k</i><sub>app </sub>= 1.40 x 10<sup>-3</sup> cm/s) ions. This is consistent with a mechanism for electron-transfer in which the Cu ions exit in different coordination environments and with different redox potentials, and are rapidly undergoing interconversion. The ability of this system to facilitate the electron-transfer process to the redox probe was used to develop a new cyanide sensor. Addition of cyanide ions increases the blocking behaviour of the SAM, suggesting the elimination of Cu from the SAM to form [Cu(CN)<sub>n</sub>]<sup>(n-1)- </sup>complexes. The cyanide detection limit was found to be 1 nM. Electrodes modified with the binucleating ligand 2,6-bis[bis(2-pyridylmethyl)amino-methyl]phenol thioctic acid derivative (bearing two BPA arms) L7 were also investigated. Metal containing SAMs can influence the electron-transfer process through the SAM to a solution containing a redox probe. This property can be used to develop new anion sensors in aqueous system. |
author |
Calatayud Sanz, Maria Pilar |
author_facet |
Calatayud Sanz, Maria Pilar |
author_sort |
Calatayud Sanz, Maria Pilar |
title |
Self-assembled monolayers of metal complexes attached to gold electrodes |
title_short |
Self-assembled monolayers of metal complexes attached to gold electrodes |
title_full |
Self-assembled monolayers of metal complexes attached to gold electrodes |
title_fullStr |
Self-assembled monolayers of metal complexes attached to gold electrodes |
title_full_unstemmed |
Self-assembled monolayers of metal complexes attached to gold electrodes |
title_sort |
self-assembled monolayers of metal complexes attached to gold electrodes |
publisher |
University of Edinburgh |
publishDate |
2009 |
url |
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642311 |
work_keys_str_mv |
AT calatayudsanzmariapilar selfassembledmonolayersofmetalcomplexesattachedtogoldelectrodes |
_version_ |
1718142069307867136 |