Document Details

Document Type : Thesis 
Document Title :
COORDINATIVELY UNSATURATED METAL COMPLEXES AS PRECURSORS IN DESIGNING NOVEL COMPLEXES
متراكبات الفلزات غير مشبعة التناسق كبادئة في تصميم متراكبات مستحدثة
 
Subject : Chemistry 
Document Language : Arabic 
Abstract : Dichlorotris(triphenylphosphine)ruthenium(II) RuCl2(P?3)3 is a coordinately unsaturated complex, in the sense that all the sites in its first coordination sphere are not occupied. It can undergo addition, elimination and addition elimination reactions and hence as a precursor in the syntheses of a large number of complexes that find important applications in catalysis and/or chemotherapy. In this study the synthetic versatility of this complex is explored by its reaction with a number of monodentate and bidentate nitrogen donor ligands, viz. imidazole, ethylenediamine, 1,10-phenanthroline, 2,2-bipyridyl, adenine, adenosine, cytidine, adenosine-5-triphosphoric acid, 2-deoxy-d-ribose, as well as solvent molecules such as dichloromethane, methanol, dimethyl sulfoxide, dimethyl formamide, pyridine and acetonitrile. Ruthenium(II) is attractive because strong-field low spin d6 metal centers with pseudo-octahedral symmetry exhibit very large ligand field splittings and stabilization energies. In addition, Ru2+ is classified as a borderline acid and as such exhibits an affinity to borderline bases such as the nucleosides used in this work. The present work was investigated by the literature preparation of RuCl2(P?3)3 and RuCl2(P?3)4. Both complexes are slightly soluble in dichloromethane, methanol and benzene. The latter complex loses a triphenylphosphine ligand and identical spectra (UV-VIS and solution IR) are observed for both complexes. In fact the five coordinate complex loses a triphenylphosphine ligand to give RuCl2(P?3)2 in absence of added triphenylphosphine. Dissociation of P?3 is a common phenomenon in ruthenium complexes such as [RuCl2(P?3)n] (n = 3 or 4). The interaction of RuCl2(P?3)3 with the ligands mentioned above was investigated. Complexes formed in solution as well as those isolated in the solid state were studied by a variety of techniques. The binding constant for the reaction of the parent complex with adenine as a representative one, was done spectrophotometrically. All complexes were subjected to conductometric studies that showed that all except the ethylenediamine complex are electrically non-conducting. The structure and physicochemical behavior was inferred from micro-analytical data, UV-VIS spectra, IR spectra and NMR spectra. All complexes gave no ESR signals and hence all the complexes are diamagnetic and NMR active. Thus the oxidation state of the metal ion is +2 and it is in a low-spin state in each complex. 
Supervisor : Prof. Abbas Abbas Al-Awadi 
Thesis Type : Master Thesis 
Publishing Year : 1428 AH
2007 AD
 
Co-Supervisor : Dr. Hanaa Asaad Gazzaz 
Added Date : Monday, June 9, 2008 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
عبادة محمد حتاحتHatahet, Obadh MohammedResearcherMaster 

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