Studies On Design,Preparation And Properties Of Half-Sandwich Iridium And Rhodium Complexes

In the past two decades, the half-sandwich structures of Ir, Rh compounds has become the focus of organometallic compounds. As a precursor, [Cp*M??-Cl?Cl]2?M = Ir, Rh? is easy to synthesize, and it has a good reaction activity, a wild rang chemical properties. Easy synthesis is a big advantage for this precursor. So this paper is developed based on the Ir and Rh compounds with the half-sandwich structure. This thesis is divided into four chapters:In Chapter 1, we summarized the structural characteristics of half-sandwich structures of Ir, Rh. And a comprehensive summary of supramolecular transformations within discrete coordinationdriven upramolecular architectures is presented. Additionally, an overview of the thesis topic and progress are also presented.In Chapter 2, Bidentate organochalcogen selenium ligand can be easily prepared by using different imidazole salt react with selenium powder. The NMR and X-ray single crystal diffraction confirmed that the result structure is a series of unsaturated 16-electron M₂L₂-type macrocyclic complex. In these half-sandwich complexes molecular structures, the selenium atoms are coordinated with centre metal. All compounfs have been characterized by NMR and elemental analysis. The ligands introduced in Cp* system may change the complexes structures.In Chapter 3, we first report unusual organometallic transformations in solution that can be accomplished by uptaking or releasing of H₂. An efficientroute for synthesizing air- and moisture-stable 16-electron M₂L₂-type metallacycles under very mild conditions has been developed. The reaction of a coordinatively unsaturated 16-electron M₂L₂-type macrocyclic complex featuring seleone ligands with 1 atm of H₂ leads to the isolation of a 18-electron M2L3-type cylinder, along with hydride species. Remarkably, the obtained mixture underwent loss of H₂ in a facile manner upon heating to reform the starting M₂L₂-type complex. A possible mechanism is proposed for the reversible transformations. Secondly, we have demonstrated the use of a metalated binuclear iridium complex as a chromogenic system for carbon monoxide sensing. Color modulations are due to coordination of CO at axial positions. This probe shows exceptional sensitivity and selectivity in its sensing behavior in the solid state. A color response visible to the naked eye is observed at 5 ppm of CO, and a remarkably clear color change occurs from black to yellow at the onset of toxic CO concentrations?50 ppm? in air. As additional features, the system is selective and fully reversible.In the last Chapter, an efficient method for the synthesis of highly popular N-containing heterocyclic compound from imidazolium substrate and alkyne was described. Treatment of diphenylacetylene with diimidazolium in the presence of [Cp*RhCl2]2, NaOAc, AgOTf led to compound in 80% yield. The object molecule was characterized by NMR spectroscopy?1H, 13 C, COSY, HSQC and HMBC? and single-crystal structure.