Synthesis characterization and reactivity of some mixedligand complexes of dioxouranium VI UO

Abstract

Investigations into some aspect of chemistry of mixedligand coordination compounds of dioxouranium ( VI ), [ UO2 ]2+, in aqueous medium form the basis of the present thesis. The contents of the thesis has been laid out over Six Chapters. Each chapter is virtually self-contained one with the relevant references cited at the end of each chapter. Chapter III - VI is concerned with the description of actual work carried out as a part of the present Ph. D. programme. The general lay - out pattern for these chapters is a short and focussed introduction related to the theme of the chapter followed by experimental and then an interpretative account in the form of a results and discussion and finally the references. Chapter I portrays a brief introductory overview pertaining to the work embodied in the thesis. The importance of and interest in the chemistry of actinides, in general, and uranium (VI), in particular have been highlighted. Attention has also been drawn to the contemporary significance of 5f-element chemistry with special reference to the environmental relevance. Problems encountered in the synthesis and reactivity of uranium (VI) - complexes with the chosen ligands vis-a-vis the scope of research has also been enumerated in this chapter. Incorporated in Chapter II are the details of the method of elemental analyses and particulars of instruments / equipments employed for characterisation and structural assessment of the newly synthesised complexes. Procedure for obtaining deoxygenated water for reactivity studies has been furnished in this chapter. Chapter III of the thesis presents an account of synthesis of novel dinuclear mixedligand and peroxouranates (VI) of the general formula [(UO2)2(O2)3 L (H2O)2]3-. The coligands (L) are biologically relevant ones with N and / or O donor sites. The structural motifs has been established on the basis of vibrational spectroscopy (IR and LR). Evidence for both n2 and o:o type peroxide linkages has been furnished. An aqueous solution of salicylate and aspartate...