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The synthesis, structure, photophysical and electrochemical properties of cyclometalated iridium complexes with ancillary cyano and isocyanide ligands are reported. The lack of solvatochromism and highly structured emission has indicated that the lowest energy excited state is triplet ligand centered with some admixture of singlet metal-to-ligand charge-transfer character.

The assembly of Ir4(Co)12 from Ir(CO)2(acac) precursors in the supercages of the zeolite NaY is investigated by extended X-ray absorption fine structures (EXAFS) and in-situ infrared (IR) spectroscopies. The results revealed that conditions of pretreatment of the zeolite significantly affect the chemistry of the intercage cluster assembly of Ir4(Co)12 in zeolites nanopores.

The article explains the formation and properties of a solution processable single layer organic light-emitting device, which is shown to consist of a single small molecular ionic iridium compound. The application of a phosphorescent OLED (PHOLED) is shown to be extremely beneficial for enhancing the performance of the device.

The isomerization of N,N-trans-mer-heteroleptic iridium complex to a more stable cis-mer-isomer observed during the preparation of vacuum-processed organic light-emitting devices (OLEDs) and reproduced in solution is described. The mixture of isomers could be used to prepare polymer-based devices, which could find application as an emitter of better purity.

The synthesis and the x-ray diffraction patter, magnetic susceptibility, and electrical resistivity of the orthorhombic phase of SrIr[O.sub.3] is described. The magnetic and electrical properties showed that the orthorhombic SrIr[O.sub.3] perovskite is paramagnetic below 170 K and is metallic above 44 K before a band type metal insulator transition appeared.

Potentiostatic intermittent titration technique (PITT) and electrochemical impedance spectroscopy (EIS) are examined in order to determine the solid phase chemical diffusion coefficient and electron density of states (DOS). PITT and EIS have indicated that the intercalated charge as a function of potential has displayed a shape resembling the theoretical DOS of crystalline iridium oxide, especially for IrTaOx.

The atomic layer deposition of iridium and iridium oxide films is examined by using an alternating supply of (ethylcyclopentadienyl)(1,5-cyclooctadiene) iridium and oxygen gas. The phase transition between Ir and Ir[O.sub.2] has occurred at the critical oxygen partial pressure during the oxygen injection pulse.

A new technique for selective low-temperature syntheses of various facial and meridional tris-cyclometalated iridium(III) complexes has been developed. The technique can also be employed for the development of isomers of other C-N ligands and heteroleptic complexes.

The quantitative determination of the hydration structure of hexaaquairidium(III), [[Ir[([H.sub.2]O).sub.6]].sup.3+], the most inert aqua ion, in aqueous solution obtained by employing experimental-theoretical X-ray absorption spectroscopy and molecular dynamics simulations is presented.

The x-ray magnetic circular dichroism (XMCD) spectroscopy with transmission mode of Mn-Ir/ferromagnetic (FM) bilayers is used to investigate the microscopic origin of the uncompensated antiferromagnetic (AFM) spins. The results have shown that the uncompensated Mn components are induced through the exchange interaction between the FM and AFM layers and are localized at the very interface.

A series of new cationic iridium(III) complexes containing [Ir[(piq)2(N^N)].sup.+]P[F.sub.6.sup.-] (piq = 1-phenyl-isoquinoline) containing N^N ligand with different conjugated lengths are synthesized and their chemical structures, excited-state properties are investigated by theoretical calculations and photophysical and electrochemical properties. The excited state of complexes is complicated and contains triplet metal-to-ligand charge transfer, triplet ligand-to-ligand charge transfer and ligand-centered (cyclometalated) transitions simultaneously and significant emission wavelength tuning is achieved by changing the conjugated length of the diimine ligands.

The spectroscopic, electrochemical and electroluminescent properties of a multifunctional iridium complex are discussed. Devices fabricated from [lr(ppy)2-(dtb-bpy)](super +(PF6)(super -) emitted yellow light with a brightness exceeding 300 cd/m2 and a luminous power efficiency exceeding 10 Lm/W at just 3V.

The spectral characteristics of PVK film doubly doped with two phosphorescent dyes ca. green Ir(ppy)(sub 3) and red [Ru(4,7-Ph2-phen)(sub 3)](super 2+) (or PtOEP) in photoexcitation and EL devices is presented. The relationship between R(sub i) and R(sub c) is found to depened on the driving voltage, which reflects that the various mechanisms (singlet energy transfer and charge trapping) may contribute to the emission process of phosphorescence polymer LEDs.