A focus in this thesis is the study of Investigation the Photochemical Properties of Ruthenium Polypyridyl Complexes using High Performance Liquid Chromatography (HPLC). In chapter 1, topics relevant to the studies presented in this thesis are introduces. An introduction highlights the literature relevant to the topic. In Chapter 2, the experimental and optimisation of conditions of the various methods of characterisation a setup of HPLC are described. A theoretical background for the experimental and computational techniques used is also given. In Chapter 3, we have presented the separation of the tow stereoisomers of [(Ru(bpy)2)2(bpt)](PF6)3 the application of separation of dinuclear ruthenium(II) polypyridyl complexes is examined. In particular the importance of both by semi preparative HPLC using cation exchange column and 1H NMR spectroscopy. after three hours of irradiation at 430 nm the isomers constituting fraction A are converted into the isomers forming fraction B as detected through 1H NMR spectroscopy and HPLC. For both fractions A and B of, further irradiation produces the fragmentation of the dimetallic complex into monometallic species. Such a photolytic reaction is catalysed by the presence of chloride anions. In particular, photofragmentation of complex consists of the loss of the ruthenium centre bound to the N4-site of triazole ring.