One of the main challenges for the creation of artificial light harvesting systems is to develop high-yielding and easy-to-implement protocols for the assembly of chromophores into spatially organized architectures. The use of a template bearing pre-programmed receptor sites accommodating selectively specific chromophores appears to be a very attractive synthetic approach. In this manuscript, pre-programmed peptides will guide the spatial arrangement of different dyes, acting as energy donors and acceptors and absorbing over the whole visible spectrum. The self-assembly of the chromophores into the scaffold can be achieved through the engineering of orthogonal recognition motifs. The employed method, described in Chapter 2, relies on the development of simultaneous multireaction systems. A triorthogonal system involving three reactions of dynamic covalent chemistry, namely disulfide exchange, boronate and acyl hydrazine formations, is first optimized for the design of triorthogonal recognition motifs. The complexity of the system is then increased by incrementally adding reactions: the strain promoted azide-alkyne cycloaddition and the inverse electron demand Diels-Alder cycloaddition between s-tetrazine and trans-cyclooctene leading to tetra- and pentaorthogonal recognition motifs. Chapters 3 and 4 address the creation of a library of multichromophoric architectures with tailored yellow, red and blue chromophores through the three simultaneous reactions of dynamic covalent chemistry. In this respect, the design and synthesis of various α-helix peptides bearing disulfide, diol and hydrazide acting as receptor sites at given positions and chromophoric units with complementary sticky sides are detailed, as well as the dyes assembly leading to excitation energy transfer within the colored structure. Finally, Chapter 5 focuses on the extension of the absorption range of the colored architectures by selectively incorporating additional dyes following their energy gradient to favor the unidirectionality of the energy transfer. This will be achieved through the introduction of the tetra- and pentaorthogonal recognition motifs within the peptide and the dyes (Figure 1).
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:742859 |
| Date | January 2018 |
| Creators | Rocard, Lou |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/111135/ |
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