الفهرس 
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Abstract
The design and synthesis of bimetallic complexes is of significant interest to various areas of chemistry. Originally motivated by biology, the synthesis of bimetallic complexes allowed scientists to explore the coordination environments of various metal centers at biologically active sites. Bimetallic complexes also have significant benefit to the fields of catalysis, activation of organic and inorganic molecules, solar energy harvesting and general coordination chemistry. Molecules containing more than one metal center can exhibit profoundly different physical properties and reactivity to monometallic complexes, particularly where there is a strong interaction between the metal centers. Therefore, the rational and intelligent design of the coordinating ligand becomes of paramount importance when attempting to illicit a cooperative effect by complexing two distinct metal centers within a close proximity. Pyrazine-based ligands play an important role in the coordination chemistry of homo- and hetero bimetallic complexes.
The current study comprises three main sections: the first section discusses the synthesis and characterization of a set Ruthenium -dipyridyl quinoxaline derivative complexes, including the states of zero-valent ruthenium represented in its carbonyl precursor, and the state of the trivalent ruthenium represented in its trichloride precursor, along with two dipyridyl quinoxaline (dpq) derivatives (dichloro- and dimethyl-), which yielded 6 complexes of different nuclearity.
The second section involves the synthesis and characterization of complexes of Ruthenium bis-bipyridine with derivatives of the dipyridyl quinoxaline derivatives (dpq) acting as a bridging ligand, to yield a set of comparable complexes along the two derivatives with various nuclearity and the successful implementation of one class of the complexes of ruthenium (II) – dichloro-(dpq) derivatives in DNA binding applications.
Chapter one: is comprised of an introduction and literature surveying to the Ruthenium atom and its different valences including Ru0 represented in Ruthenium carbonyl and its complexes, Ru3+ represented in Ruthenium trichloride and its complexes, and Ru2+ represented in the well-known Ruthenium trisbipyridine ion and its complexes.
Chapter two: This chapter describes all experimental procedure including, the synthesis of one of the ligand derivatives, all thermal reactions, the analytical methods implemented in characterization, in addition to the materials and reagents used throughout the research.
Chapter three: Thermal reactions of triruthenium dodecacarbonyl with two dpq derivatives have resulted in a dinuclear and a mononuclear complex as confirmed by elemental analysis and mass spectrometry data, both complexes have been characterized by analytical methods including FTIR, UV-Vis spectroscopy, 1HNMR, and cyclic voltammetry. Additionally, computational analyses using the density function theory (DFT) have been performed to obtain the optimized stereostructure of the complexes.
Moreover, the thermal reaction of ruthenium trichloride with the dpq derivatives have yielded mononuclear metal complexes in accordance with the previous work. These complexes have been fully characterized and in turn implemented in the synthesis of the novel trinuclear moieties comprising Ru0/RuIII/Ru0 in a trinuclear environment. The novel complexes have been fully characterized by the aforementioned analytical techniques.
Chapter four: This chapter depicts the synthesis of bis-bipyridine Ru(II) complexes of various nuclearity. For this purpose, the Ru(II) precursor and the dpq derivative were mixed in ethanolic solution and refluxed under nitrogen atmosphere. The impure crude product was purified by column chromatography to yield a mononuclear and dinuclear complexes of Ru(bpy)2 and the dpq-derivative. Additionally, the mononuclear complex was thermally reacted as a precursor with RuCl3 in a 2:1 ratio, which as anticipated, has successfully yielded the trinuclear complex of the Ru(II)/ Ru(III)/ Ru(II) regimen. All complexes were fully characterized by the previously mentioned spectroscopic techniques in addition to the electrochemical studies by cyclic voltammetry. Additionally, NIR-spectroscopy was conducted which showed the well-known IVCT band, which is a characteristic of the intermolecular electronic exchange.
Chapter five: in this chapter, DNA binding with metal complexes studies, certainly with a special emphasis on ruthenium complexes, were surveyed in literature. Then the results of the DNA interaction experiments conducted on selected set of complexes (complexes 1, 2 and 3) of the bis-bipyridine-(dichloro-dpq) family, with the well-known CT-DNA were presented and fully interpreted. The performed tests include UV-absorption studies, steady-state fluorescence quenching, viscosity measurements in addition to the antioxidant activity to evaluate the scavenging profile. The studies have revealed the capability of the complexes to intercalate with CT-DNA to various extents, in addition to their noticeable and promising scavenging activity.