Syntheses And Characterization Of Ruthenium Complexes Containing Cyclen And Pyridine Ligands

1,4,7,10-Tetraazacyclododecane(Cyclen)is of specially structural framework along with stable coordination ability.Transition metal complexes with Cyclen could be potentially applied in bioinorganic,organic catalysis and supramolecular chemistry.Synthetic reaction,structural analysis and photocatalytic properties for hydrogrn production by water oxidation of ruthenium(II)complexes containing Cyclen and pyridine-based ligands were mainly reported in this thesis.[(Cyclen)RuCl(DMSO)]Cl(1)was prepared with an improvement method according to the literature,isolated in a relatively high yield with high purity.Complex 1 as the starting material,reacted with mono-,bi-and ter-pyridine ligands in the presence of zinc powder were carried out,and new ruthenium(II)complexes were characterized by ¹H NMR,FT-IR,UV-vis and fluorescence spectroscopies.Treatment of complex 1 with monopyridine ligands e.g.4-^tBupy,py in the presence of KPF₆and Na Cl O₄in acetonitrile solution afforded ruthenium(II)complexes[(Cyclen)Ru-(DMSO)(NCMe)][PF₆]₂(2a')and[(Cyclen)Ru(DMSO)(NCMe)][Cl O₄]₂(2b'),respectively,pyridine ligands,instead of acetonitrile solvent,did not participate in the coordination.Treatment of complex 1 with py in the presence of triethylamine in deionized water gave ruthenium(II)complex[(Cyclen)Ru(py)₂][Cl O₄]₂(2d).Reaction of complex 1 with bipyridine ligands e.g.phen,5,5'-Me₂bpy,4,4'-^tBu₂bpy in an absolute ethanol gave according ruthenium(II)complexes[(Cyclen)Ru(phen)][PF₆]₂(3a),[(Cyclen)Ru(5,5'-Me₂bpy)][PF₆]₂(3c)and[(4,4'-^tBu₂-bpy)₃Ru][Cl O₄]₂·2CH₃CN(3d').Treatment of complex 1 with terpyridine ligand e.g.4'-phtpy,4'-(4-CH₃)phtpy in an absolute ethanol gave corresponding ruthenium(II)complexes and by-product[(4'-phtpy)₂Ru][PF₆]₂·H₂O(4a')in a relatively long reaction time.The structures of all isolated complexes have been established by single-crystal X-ray crystallography and electrochemical and photocatalytic properties were also investigated.It was found that ruthenium(II)complexes 3a,3b and 3c are of electro-oxidation reduction activity and stable performance for hydrogen production by water oxidation,which could be applied as a kind of potential photocatalytic catalysts.