Study On Synthesis And Technology Of Iridium Complexes

In platinum group metal elements, Iridium has many unique physical and chemical properties. It has the highest density metal, high melting point, large elastic modulus, and it is hard for mechanical processing. Also it has good stability in high temperature, chemical inertness, and can prevent oxygen diffusion. Iridium can’t dissolve in all inorganic acids including aqua regia and also can’t be corroded by melting reagents and high-temperature silicate. In addition, its oxides have excellent electrical conductivity, et al. Therefore, it generally tends to be used as the structure of device of high temperature resistant and corrosion resistance in the turbine engine of the spacecraft. Moreover, iridium has the d orbitals. When it forms complexes with ligands, the complexes can generate strong spin-orbit coupling and produce phosphor emission, also its triplet life is short. So iridium complexes are widely used in phosphor luminescence materials. While iridium (Ⅲ) has a d2 sp3 hybridized orbit, it can accept the lone pair electrons to form a strong metal-metal bonding and metal-ligand bonding and show that the catalytic activity, so are widely used in catalysis.In this article, we prepared iridium trichloride hydrate crystals using chlorine iridium acid as raw material and hydrazine hydrate as reducing agent. And then Iridium trichloride hydrate was used as the raw material, iridium tris(acetylacetonate) was synthesized by chemical precipitation method.In the preparation of iridium trichloride trihydrate, valence state of iridium was characterized employing X-ray photoelectron spectroscopy. The TG/DSC and XRD analysis indicated that its composition was IrCl3·3H2O. And the influence of hydrochloric acid was studied, when the concentration of hydrochloric acid solution was 3 mol/1, high purity trihydrate trichloride iridium can be prepared.The results reavealed that the amount of affects the preparation process.In the preparation of iridium tris(acetylacetonate), the component and structure of the complex were determined by the analytical means such as UV-vis, FITR,’HNMR, EI-MS and Organic Elemental Analysis. We also studied how the hydrated iridium trichloride concentration, acetylacetonate concentration, sodium bicarbonate concentration, the amount of deionized water, the reaction temperature and reaction time impact on the yield of the synthesis. When the mass ratio of hydrated trichloride iridium: acetyl acetone:sodium bicarbonate:deionized water was 1:1.96:4.1:15, we could receive the highest yield up to 42.8% of the sample. Besides, we disscussed the synthesis mechanism of iridium tris(acetylacetonate) in aqueous solution and analyzed the reasons leading to the low synthesis yield of iridium tris(acetylacetonate) in aqueous solution.