Two-Coordinate Thermally Activated Delayed Fluorescence Coinage Metal Complexes: Molecular Design, Photophysical Characters, and Device Application.

Since the emergence of the first green light emission from a fluorescent thin-film organic light emitting diode (OLED) in the mid-1980s, a global consumer market for OLED displays has flourished over the past few decades. This growth can primarily be attributed to the development of noble metal phosphorescent emitters that facilitated remarkable gains in electrical conversion efficiency, a broadened color gamut, and vibrant image quality for OLED displays. Despite these achievements, the limited abundance of noble metals in the Earth's crust has spurred ongoing efforts to discover cost-effective electroluminescent materials. One particularly promising avenue is the exploration of thermally activated delayed fluorescence (TADF), a mechanism with the potential to fully harness excitons in OLEDs. Recently, investigations have unveiled TADF in a series of two-coordinate coinage metal (Cu, Ag, and Au) complexes. These organometallic TADF materials exhibit distinctive behavior in comparison to their organic counterparts. They offer benefits such as tunable emissive colors, short TADF emission lifetimes, high luminescent quantum yields, and reasonable stability. Impressively, both vacuum-deposited and solution-processed OLEDs incorporating these materials have achieved outstanding performance. This review encompasses various facets on two-coordinate TADF coinage metal complexes, including molecular design, photophysical characterizations, elucidation of structure-property relationships, and OLED applications.

Simultaneous Thermally Stimulated Delayed Phosphorescence (TSDP) and Thermally Activated Delayed Fluorescence (TADF) in a Two-Coordinated Au(I) Bimetallic Complex Featuring a Tandem Carbene Structure.

A bimetallic, two-coordinated carbene-metal-amine (cMa) Au(I) complex featuring a twisted tandem carbene structure (NHC1-Au-NHC2-Au-carbazolyl) was synthesized. The molecular structure in single crystals revealed a large dihedral angle between the two carbene ligands, while the bridged carbene NHC2 and carbazolyl (Cz) ligands were coplanar. A bluish green thermally stimulated delayed phosphorescence (TSDP) was observed in crystals with an emission lifetime over 70 µs, which can be attributed to the spin allowed diabatic population of a high-lying emissive triplet state from the 3LE characterized low-lying ones. The small rotation energy barrier of Cz along the coordination bond allowed conformers with large dihedral angles between NHC2 and Cz. The ICT characterized S1 state was consequently stabilized to achieve a thermally accessible energy gap to facilitate ISC between triplets and the S1, leading to the thermally activated delayed fluorescence (TADF). Simultaneous TSDP and TADF dual emission can be recorded in its doped polymer film owing to the coexistence of these different conformers.

Inhibition Effect of Pseudomonas stutzeri on the Corrosion of X70 Pipeline Steel Caused by Sulfate-Reducing Bacteria.

Microbiologically influenced corrosion (MIC) is a common phenomenon in water treatment, shipping, construction, marine and other industries. Sulfate-reducing bacteria (SRB) often lead to MIC. In this paper, a strain of Pseudomonas stutzeri (P. stutzeri) with the ability to inhibit SRB corrosion is isolated from the soil through enrichment culture. P. stutzeri is a short, rod-shaped, white and transparent colony with denitrification ability. Our 16SrDNA sequencing results verify the properties of P. stutzeri strains. The growth conditions of P. stutzeri bacteria and SRB are similar, and the optimal culture conditions are about 30 °C, pH 7, and the stable stage is reached in about seven days. The bacteria can coexist in the same growth environment. Using the weight loss method, electrochemical experiments and composition analysis techniques we found that P. stutzeri can inhibit the corrosion of X70 steel by SRB at 20~40 °C, pH 6~8. Furthermore, long-term tests at 3, 6 and 9 months reveal that P. stutzeri can effectively inhibit the corrosion of X70 steel caused by SRB.

[Study on all-round evaluation of biocompatibility of biomaterial].

Biocompatibility has always been the focal point in the study of biomaterials applied to medical apparatus. But at present, the standard system hasn't formed completely to evaluate the biomaterials. In recent years scientists tend to use general standard of evaluation. In this article, based on the recalcification time, the adhesion of platelets as well as the total quantity of plasma protein and some other evidences, combining with the Analytic hierarchy process (AHP), the method of general evaluation on the biocompatibility of anticoagulant biomaterials was discussed.

Investigation on clotting and hemolysis characteristics of heparin-immobilized polyether sulfones biomembrane.

In this study, a novel heparin-immobilized polyethersulfone (PES) was synthesized. PES was initially sulfonated with chlorosulfonic acid and then 1,6-hexanediamine was grafted to the -SO(3)H groups of sulfonated PES, which subsequently reacted with heparin through a covalent bond by using (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC) as catalyst. The hydrophobic/hydrophilic property was characterized by measuring the water contact angle. The data shows decline from 62.29 degrees +/- 1.2 degrees to 47.86 degrees +/- 0.3 degrees for water and 86.79 degrees +/- 0.8 degrees to 68.34 degrees +/- 1.0 degrees for glycerol, which indicates an enhancement of hydrophilicity. Plasma hemolysis assay shows a comparatively low hemolysis ratio of 1.04%, which is below permissible limit of 5%. A higher content of dissociated blood cells and Ca(2+) concentration was found in red blood cell counting and coagulation factor IV test in heparinized PES. Plasma recalcification time of 360 s also offers positive evidence that heparinized PES seems to have a good anticoagulation property. This new heparin-immobilized PES biomaterials may have the potential for biomedical applications.