RESUMEN

Transition metal carbonyl compound of CO releasing molecules (CORMs) are widely used to treat arthritis, tumor and immune. They play a physiological role by directly acting on target tissues to release CO for disease treatment without matrix metabolism after dissolution. It is important to track the level and diffusion process of CORMs in vivo to control CO dose and distribution, facilitating to understand the roles of CORMs in disease treatment. Herein, we designed two red ring Ir1/2 complexes with a large stokes shift. Both Ir1 and Ir2 complexes probes can sensitively and selectively respond to CORM-2. The probe Ir1 exhibits rapid reaction with CORM-2 in Phosphate Buffered Saline within 1 min, showing a detection limitation of 0.13 µM and manifesting a linear relationship with the CORM-2 concentration from 0 to 70 µM at λem = 618 nm. Due to low toxicity even after 12 h exposure and fluorescence stability, this probe has been successfully used for continuous tracking the diffusion process of CORM-2 in living cells for up to 60 min and visualizing CORM-2 distribution in zebrafish. Additionally, this probe showed a good capacity for deep penetration (126 µm), suggesting the potential in detecting CORM-2 in living tissues.

Asunto(s)

Neoplasias , Compuestos Organometálicos , Animales , Pez Cebra , Iridio , Compuestos Organometálicos/toxicidad

RESUMEN

Photoinduced electron transfer in transition-metal complexes linked to a fullerene moiety is of increasing interest. Recently, several stereoisomers of an Ir-complex exhibiting configurational stability at metal center, which does not undergo epimerization have been synthesized (Angew. Chem. Int. Ed. 2017, 56, 2136). The presence of multiple electron donor and acceptor sites located at opposite ends with respect to the metallic center creates the prerequisites for the formation of entirely different charge transfer (CT) states. Here we report the results of quantum mechanical calculations and detailed analysis of excited-state properties for all stereoisomers of the junction. We found that the stereoisomers demonstrate clearly different CT properties by photoexcitation. The found photo-stereospecific effects can be used to design new hybrids with a different type of photoinduced CT state, exhibiting dissimilar activity in photocatalysis.

RESUMEN

It has been known for decades that the emitting dipole orientation (EDO) of emitting dyes influences the outcoupling efficiency of organic light-emitting diodes (OLEDs). However, the EDO of dopants, especially phosphorescent dopants, has been studied less than that of neat films and polymer emitting layers (EMLs) due to the lack of an apparent driving force for aligning the dopants in amorphous host films. Recently, however, even globular-shaped Ir complexes have been reported to have a preferred orientation in doped films and OLEDs. External quantum efficiencies (EQEs) higher than 30% have also been demonstrated using phosphorescent and thermally activated delayed fluorescent dyes (TADF) doped in EMLs. Here, recent results on the EDO of phosphorescent and TADF dyes doped in host films, and highly efficient OLEDs using these dyes are reviewed. The origin and control of the orientation of phosphors are discussed, followed by a discussion of future strategies to achieve EQEs of over 60% without a light extraction layer, from the material point of view.

RESUMEN

A series of highly efficient phosphorescent Ir complexes with tunable emission colors over the whole visible range have been designed and synthesized based on furo[3,2-c]pyridine ligand. By mainly varying the molecular structures of the C-chelated blocks, the emission maxima of these complexes can be obviously tailored from 477 to 641 nm while keeping the considerable photoluminescence quantum yields (PLQYs) (0.55-0.78 at wavelength of 475-560 nm and 0.10-0.34 at wavelength of 590-640 nm). Correspondingly, the phosphorescent organic light-emitting diodes (OLEDs) achieve high-performance greenish-blue, green, greenish-yellow, orange, red, and deep-red electrophosphorescence, revealing state-of-art external quantum efficiences (EQEs) of 20.0% (46.6 cd/A), 31.8% (89.0 cd/A), 19.9% (71.9 cd/A), 16.6% (38.9 cd/A), 12.0% (16.7 cd/A), and 8.5% (7.3 cd/A) as well as Commision Internationale de L'Eclairage (CIE) coordinates of (0.25, 0.48), (0.30, 0.58), (0.43, 0.54), (0.62, 0.37), (0.66, 0.32), and (0.70, 0.29), respectively. The results clearly demonstrate the great potential of furo[3,2-c]pyridine based phosphors used for full-color OLED displays.