| The present research work focuses on the coordination chemistry of two different types of monoanionic nitrogen--coordinating ligands, namely the bidentate triazenide ligand [(DippN)N(NDipp)]-- (Dipp = Pri2C6H3--2,6) (L1) and monodentate arylamido ligands [N(R)(Ar)] -- (R = SiMe3, Ar = C6H3Me 2--2,6 (L2), C6H2Me3 --2,4,6 (L3) or C6H3Pr i2--2,6 (L4); R = SiBu tMe2, Ar = C6H3Pr i2--2,6 (L5)). The first part of this work was centred on the synthesis, structural characterization and reactivity of divalent lanthanide metal complexes derived from the triazenide ligand L1. The second part of this work dealt with the chemistry of low valent and low--coordinate first row transition metal complexes supported by arylamido ligands Ln (n = 2--5). The last part of this work focused on the synthesis and structures of divalent chromium complexes derived from the L1, L4 and L5 ligands.;Chapter 1 presents an overview on divalent lanthanide complexes derived from nitrogen--coordinating ligands. The coordination chemistry of lowƒnvalent and low --coordinate first--row transition metal complexes was also reviewed.;Chapter 2 describes the preparation and characterization of samarium(II) triazenide complex [Sm(L1)2(THF) 2] (2). Complex 2 was prepared by the reaction of SmI2(THF)2 with 2 equivalents of potassium triazenide [KL1(THF)0.5] (1). The electrochemistry of 2 in THF was studied with cyclic voltammetry. Complex 2 is a strong reducing reagent. Its reactions with various inorganic/organic substrates have been examined.;Chapter 3 reports on the coordination chemistry of the triazenide ligand L1 with divalent ytterbium and europium ions.;Chapter 4 deals with the synthesis and characterization of low valent and low--coordinate first row transition metal complexes derived from arylamido ligands L2--L5.;Chapter 5 describes the preparation and characterization of three neutral two--coordinate first row transition metal complexes of the general formula [M(L5)2] (M = Fe ( 29), Co (30), Ni (31)).;Chapter 6 reports on the coordination chemistry of L 1, L4 and L5 with chromium ions.;Chapter 7 summarizes the results of the present studies. A brief description on the future direction of this research work is also presented. (Abstract shortened by UMI.). |
