Novel DNA-binding ruthenium complexes with potential surface linkers for biosensor construction

This thesis discusses the design and attempted synthesis of a DNA binding ruthenium complex with a surface linking ligand. Initially this was attempted using the tris(pyrazolyl)methane (tpm) unit that has been previously used to create a linker for other metal centres. This route was unsuccessful leading to the creation of multiple novel ligands without realising the goal of the project.

The tpm unit was utilised to construct a ruthenium complex with a thiol tail which may be used to attach to nanoparticles or a surface. While this compound was studied for its UV-Visible and luminescent properties, sufficient quantities of the compound for further study were not obtained.

Subsequently tris(pyridyl) ligands were investigated as a potential alternative. This led to the synthesis of a series of novel ruthenium complexes containing the tris(pyridyl)methylamine (tpyma) unit, not previously reported in use with ruthenium centres. The series included complexes not expected to bind to DNA, and to bind in different modes, to investigate the effect of the tpyma ligand on the DNA binding.

These complexes were found to bind to DNA in the expected mannar with association constants similar to those reported for analogues previously reported in literature. The photophysical, electrochemical and crystal structure studies are also reported. The crystal structures displayed an unexpected binding mode of the tpyma ligand making it unsuitable for the aim of the project. Subsequently attempts to synthetically alter the tpyma ligand to enable surface linkage are detailed.