Synthesis, structure, and photophysical properties of new cyclometalated iridium(III) complexes as potential phosphorescent emitters for organic light-emitting diodes (OLED)

Wydział ChemiiNiniejsza rozprawa podejmuje tematykę związków wyposażonych w motyw benzo[h]chinoliny, ukierunkowanych na zastosowanie w technologii OLED. W pracy położono nacisk na aspekt syntezy nowych związków koordynacyjnych irydu(III) będących potencjalnymi emiterami i prekursorami emiterów fosforescencyjnych oraz analizę wpływu struktury chemicznej na właściwości fotofizyczne, elektroluminescencyjne, termiczne, elektrochemiczne i spektroskopowe wybranych klas związków. W szczególności badania były skoncentrowane na kompleksach jonowych o ogólnym wzorze [Ir(bzq)2(N^N)]+A-, wyposażonych w strukturalnie zróżnicowane ligandy N,N-donorowe; kompleksach obojętnych typu [Ir(bzq)2(N^O)], stabilizowanych β-ketoiminianowymi ligandami pomocniczymi; pochodnych benzo[h]chinoliny jako prekursorów ligandów dla emiterów fosforescencyjnych; dwurdzeniowych kompleksach irydu(III) o strukturze [Ir(C^N)2(μ-Cl)]2, zwierających nowe ligandy będące pochodnymi benzo[h]chinoliny.This dissertation addresses an subject of compounds equipped with benzo[h]quinoline motif, targeted at the application in OLED technology. The work is concerned on the synthesis of novel iridium(III) coordination compounds as potential emitters and precursors of phosphorescent emitters, and the analysis of the impact of chemical structure on photophysical, electroluminescent, thermal, electrochemical and spectroscopic properties of selected classes of compounds. In particular, the studies were focused on ionic complexes of general formula [Ir(bzq)2(N^N)]+A-, equipped with structurally varied N,N-donor ligands; neutral [Ir(bzq)2(N^O)] complexes stabilized with β-ketoiminato ancillary ligands; benzo[h]quinoline derivatives as ligand precursors for phosphorescent emitters; and binuclear iridium(III) complexes of general structure [Ir(C^N)2(μ-Cl)]2, containing new ligands derived from benzo[h]quinoline

Synthesis, structure, and photophysical properties of new cyclometalated iridium(III) complexes as potential phosphorescent emitters for organic light-emitting diodes (OLED)

Wydział ChemiiNiniejsza rozprawa podejmuje tematykę związków wyposażonych w motyw benzo[h]chinoliny, ukierunkowanych na zastosowanie w technologii OLED. W pracy położono nacisk na aspekt syntezy nowych związków koordynacyjnych irydu(III) będących potencjalnymi emiterami i prekursorami emiterów fosforescencyjnych oraz analizę wpływu struktury chemicznej na właściwości fotofizyczne, elektroluminescencyjne, termiczne, elektrochemiczne i spektroskopowe wybranych klas związków. W szczególności badania były skoncentrowane na kompleksach jonowych o ogólnym wzorze [Ir(bzq)2(N^N)]+A-, wyposażonych w strukturalnie zróżnicowane ligandy N,N-donorowe; kompleksach obojętnych typu [Ir(bzq)2(N^O)], stabilizowanych β-ketoiminianowymi ligandami pomocniczymi; pochodnych benzo[h]chinoliny jako prekursorów ligandów dla emiterów fosforescencyjnych; dwurdzeniowych kompleksach irydu(III) o strukturze [Ir(C^N)2(μ-Cl)]2, zwierających nowe ligandy będące pochodnymi benzo[h]chinoliny.This dissertation addresses an subject of compounds equipped with benzo[h]quinoline motif, targeted at the application in OLED technology. The work is concerned on the synthesis of novel iridium(III) coordination compounds as potential emitters and precursors of phosphorescent emitters, and the analysis of the impact of chemical structure on photophysical, electroluminescent, thermal, electrochemical and spectroscopic properties of selected classes of compounds. In particular, the studies were focused on ionic complexes of general formula [Ir(bzq)2(N^N)]+A-, equipped with structurally varied N,N-donor ligands; neutral [Ir(bzq)2(N^O)] complexes stabilized with β-ketoiminato ancillary ligands; benzo[h]quinoline derivatives as ligand precursors for phosphorescent emitters; and binuclear iridium(III) complexes of general structure [Ir(C^N)2(μ-Cl)]2, containing new ligands derived from benzo[h]quinoline

C,N-cyclometalated iridium(III) complexes : efficient phosphorescent emitters for organic electroluminescent diodes (OLED). Part 1 and 2

Organic electroluminescent panels have been widely available on the commercial market for several years, in the form of screens used in mobile phones, tablets, and TV sets. The display panels are produced in RGB technology, in which iridium(III) coordination compounds act as phosphorescent emitters of red and green light. Because of their high emission quantum efficiency and stability, the emitters containing 2-phenylpyridinato ligands and their derivatives have proved to be particularly useful. An interesting issue was the contrast between an extensive state of knowledge on the abovementioned compounds and a poor state of knowledge on analogous iridium(III) complexes equipped with benzo[h]quinolinato ligands. Application of the latter seemed interesting because of the similar size of benzo[h]quinoline and 2-phenylpyridine coordination pockets, but much more rigid structure and a greater degree of conjugation of the former, which could have a significant impact on the properties of complexes equipped with this type of ligand. Regarding to the above, this dissertation concerns the subject of the design and synthesis of new iridium(III) coordination compounds equipped with a benzo[h]quinoline motif, as well as the analysis of the structural changes impact on the photophysical, electroluminescent, thermal, electrochemical and spectroscopic properties of selected classes of compounds targeted for the application in OLED technology. Accordingly, the article presents the results of studies on two classes of heteroleptic of C,N-cyclometalated iridium(III) complexes, namely, of the salt type with the general formula [Ir(bzq)2(N^N)]+A-, stabilized by structurally different N,N-donating ligands, as well as neutral coordination compounds of the type [Ir(bzq)2(N^O)], bearing N,O-donating ß-ketoiminato ligands in the structure equipped with aryl moieties of various structure. The work included research on the determination of the correlation between the structure of ancillary ligand introduced into the coordination sphere of the metal and the above-mentioned properties. Additionally, based on the results of quantum-chemical calculations, work was undertaken to develop synthetic pathways enabling the incorporation to the C,N-cyclometalating benzo[h]quinoline ligand of substituents characterized by different stereo-electronic properties, enabling the modification of the emission parameters of the target complexes. In the next phase of research, the functionalized precursors of the bzq ligand were successfully used in the synthesis of binuclear complexes, key reagents in the preparation of corresponding mononuclear iridium coordination derivatives with electroluminescent properties

Iridium-Promoted Conversion of Chlorosilanes to Alkynyl Derivatives in a One-Pot Reaction Sequence

By making use of the catalytic potential of the iridium system [{Ir­(μ-Cl)­(CO)₂}₂]/NEt­(<i>i</i>-Pr)₂ in the synthesis of silyl-functionalized alkynes via silylative coupling of terminal alkynes/diynes with iodosilanes, we propose a new protocol allowing employment of various mono- and dichlorosilanes as reagents. The process is based on a sequence of two reactions occurring simultaneously: i.e., conversion of initial chlorosilane (SiR¹_<i>n</i>Cl_4–<i>n</i>) to the appropriate iodosilane via Cl/I nucleophilic substitution and its further conversion to a silylalkyne derivative ((SiR¹_<i>n</i>(CCR²)_4–<i>n</i>) via iridium-catalyzed silylative coupling with terminal alkyne. Under optimum conditions, the method has proved to be effective and versatile in the conversion of a wide range of chlorosilanes to a rich portfolio of various corresponding alkynyl-functionalized silicon derivatives. Additionally, NMR studies of the equimolar reaction of a well-defined iridium­(I) alkynyl precursor with Me₃Si–I revealed that Si–I bond activation in iodosilane molecules occurred via oxidative addition to the iridium center

2-Thiohydantoin Moiety as a Novel Acceptor/Anchoring Group of Photosensitizers for Dye-Sensitized Solar Cells

Very recently, we have reported the synthesis and evaluation of biological properties of new merocyanine dyes composed of triphenylamine moiety, &pi;-aromatic spacer, and rhodanine/2-thiohydantoin-based moiety. Interestingly, 2-thiohydantoin has never been studied before as an electron-accepting/anchoring group for the dye-sensitized solar cells (DSSCs). In the presented study, we examined the applicability of 2-thiohydantoin, an analog of rhodanine, in DSSC technology. The research included theoretical calculations, electrochemical measurements, optical characterization, and tests of the solar cells. As a result, we proved that 2-thiohydantoin might be considered as an acceptor/anchoring group since all the compounds examined in this study were active. The most efficient device showed power conversion efficiency of 2.59%, which is a promising value for molecules of such a simple structure. It was found that the cells&rsquo; performances were mainly attributed to the dye loading and the ICT molecular absorption coefficients, both affected by the differences in the chemical structure of the dyes. Moreover, the effect of the aromatic spacer size and the introduction of carboxymethyl co-anchoring group on photovoltaic properties was observed and discussed

Highly efficient microwave synthesis of rhodanine and 2-thiohydantoin derivatives and determination of relationships between their chemical structures and antibacterial activity

Here we report studies on the synthesis of 12 new heterocyclic derivatives that differ in three structural motifs and the simultaneous evaluation of the impact of these three variables on the biological properties. The examined compounds are based on rhodanine and 2-thiohydantoin cores equipped with hydrogen or carboxymethyl substituents at the N-3 position and linked to a triphenylamine moiety through 1,4-phenylene, 1,4-naphthalenylene and 1,9-anthracenylene spacers at the C-5 position of the heterocycles. All the compounds were synthesized very quickly, selectively and in high yields according to the developed microwave-assisted Knoevenagel condensation protocol, and they were characterized thoroughly with NMR, FT-IR and ESI-HRMS techniques. The derivatives were tested for their activity against selected strains of Gram-positive and Gram-negative bacteria and yeast. Two compounds showed good activity against Gram-positive bacteria, and all of them showed low cytotoxicity against three cell lines of the human immune system. Based on membrane permeability assays it was demonstrated that the active compounds do not penetrate the cell membrane, and thus they must act on the bacterial cell surface. Finally, we proved that the evaluated structure modifications had a synergistic effect and the simultaneous presence of a 1,4-phenylene spacer and carboxymethyl group at N-3 caused the highest boost in antimicrobial activity