Synthesis And Characterization Of Azohetrocyclic Ruthenium (â…¡) Metal Complexes

The chemistry of transition metal complexes including azohetrocyclic ligand and itsderivatives has attracted great attention and become one of the most active topics owing to theirrich structural topologies and intriguing photophysical properties with manifold emissive origins.The photophysical properties of these complexes related significantly to central metals, theorganic ligands, can be improved by the central metal, the size of π-conjugated system, the effectof the substituents of the ligands and its position.The main achievements in my work are summarized as follow:1. To utilize Ullmann reaction, reaction of3-(2-pyridyl)pyrazole (PzPy) and1,4-bis(bromomethyl)benzene in different molar ratio gave two new ligands-PyPzCH2PhCH2Brand PyPzCH2PhCH2PzPy. Two novel transition metal complexes with mononuclear or binuclearwere prepared by reaction ligand PyPzCH2PhCH2Br or PyPzCH2PhCH2PzPy with Ru(bpy)2Cl2.The complexes were characterized and the bonding character, photophysical properties. andexcited states of the emitting Ru complexes were elucidated reasonably.2. To utilize amide reaction, two new Ru metal complexes of Ru(bpy)2(L-NHDTPA)(ClO4)2and Ru(bpy)2(Phen-NHDTPA)(ClO4)2were designed and synthesized by reaction ofRu(bpy)2(L-NH2)(ClO4)2, Ru(bpy)2(Phen-NH)(ClO4)2and multi-carboxylate ligand DTPAA.The complexes were characterized and photophysical properties have been investigated. Theresults showed that the emission energy of Ru(bpy)2(L-NHDTPA)(ClO4)2was blue shifted to ahigher energy as compared with complex Ru(bpy)2(L-NH2)(ClO4)2whereas that of Ru(bpy)2(Phen-NHDTPA)(ClO4)2was red shifted as compared with Ru(bpy)2(Phen-NH)(ClO4)2. Theresults showed that the desired two Ru (П) complexes were better soluble in water and morestronger luminescence than that of Ru(bpy)2(L-NH2)(ClO4)2, Ru(bpy)2(Phen-NH)(ClO4)2respectively. The photophysical properties and excited states of the Ru (П) complexes wereelucidated reasonably.3. To utilize Sciff reaction, a new π-extended bridging ligand phen-NNa was prepared viadirect imide condensation of1,8-naphthalic anhydride with5-amino-1,10-phenanthroline. Three new Ru metal complexes of Ru(bpy)2(Phen-NNa)Cl2, Ru(phen)2(Phen-NNa)(PF6)2andRu(Phen-NNa)3(NO3)2were designed and synthesized. The complexes were characterized andphotophysical properties have been investigated. When introducing a large π-conjugationchromophore1,8-naphthalimide unit into ligand for developing Ru(II) complexes, the resultsshowed that the complexes had a wide absorptive region and good fluorescence intensity, Thephotophysical properties and excited states of the Ru (П) complexes were elucidated reasonably.The interaction between complexe Ru(bpy)2(Phen-NNa)Cl2and calf thymus DNA wasinvestigated by spectroscopic measurements, which suggested that the complex binded to DNAwas via a part of intercalative mode.