Gold-decorated ligands with photoactive properties

A series of new phosphinegold(I) decorated ligands was obtained via multi-step synthesis. The luminescent properties of the unique molecular system consisting of the p-electron rich 4,4'-diethynyl-2,2'-bipyridine or 4'-ethynyl-2,2':6',2''-terpyridine substituted by phosphinegold(I) units can be tuned by the coordination of different transition metal-ions to polypyridine moieties or even quenched as in the case of the Fe(II) complexes.
Eleven ligands L1-L11, six of (R3PAu−≡)2bpy type and five of PR3Au−≡−tpy type, were synthesised and their characterisation (excluding two) by NMR, UV-Vis, fluorescence spectroscopies and X-ray diffraction is described in chapters 3 and 4. The emission spectra of the ligands have been measured, demonstrating the luminescent properties of these kinds of compounds and studies of their crystal structures reveal an interesting relationship between the steric hindrance of the phosphine moieties and the existence of aurophilic interactions for L1-L9.
Complexes of these ligands with Zn(II), Fe(II) and Ru(II) are discussed in chapter 5 and their NMR spectra show characteristic changes of the chemical shifts of the proton peaks caused by complexation. Preliminary studies of Fe(II) and Zn(II)-complexes with a bridging ligand (L8) show the possibility of macrocycle formation consisting of two ligands and two metal-ions and they are also described in this chapter.
Potentially, compounds L1-L9 with regards to their luminescent properties and anticipated (but not tested), bioactive properties as in the case of many other gold(I) compounds (see chapter 1) may find applications in the antiviral and ani-tumor therapy.