Isomeric Tetradentate Ligand-Containing Cyclometalated Gold(III) Complexes.

A simple one-pot two bond-forming reaction for the rapid construction of cyclometalated gold(III) complexes with fully π-conjugated tetradentate ligand is reported. The coupling of the bifunctional gold(III) precursor with the bifunctional aromatic compound has led to the formation of two regioisomers with either C- or N-coordination. Through monitoring by high-throughput high performance liquid chromatography, the regioselectivity of the reaction has been effectively tuned toward the formation of a single isomer, allowing easy separation of the metal complexes. The structures of the complexes have been determined by X-ray crystallography, and the photophysical, electrochemical, and electroluminescence (EL) studies have been carried out. Computational study has been performed to provide insights into the nature of the excited states. Isomeric effect has been shown to have a significant influence on the EL behavior of the organic light-emitting devices.

Vasitis: a rare diagnosis mimicking inguinal hernia: a case report.

BACKGROUND: Vasitis or inflammation of the vas deferens is a rare condition, and few case reports with computed tomography images have been published since 1980. CASE PRESENTATION: A 50-year-old man presented with severe right inguinal and lower abdominal pain. Initial diagnosis at the emergency department was incarcerated or strangulated inguinal hernia. The computed tomography scan revealed diffuse edematous changes of right spermatic cord and vas deferens with peripheral fat stranding. Correlating with his clinical symptoms, signs, and imaging findings, the diagnosis of vasitis was made. We report a case of acute vasitis about the cause, symptom, pathogen, differential diagnoses, image findings, and treatment. CONCLUSION: Although very rare, vasitis should be listed as one of the differential diagnosis for inguinal mass lesions. Cross-sectional imaging may be necessary to confirm the diagnosis and exclude differentials such as an inguinal hernia. Recognition of the characteristic image findings can help to make the correct diagnosis and avoid unnecessary surgery.

Highly Emissive Fused Heterocyclic Alkynylgold(III) Complexes for Multiple Color Emission Spanning from Green to Red for Solution-Processable Organic Light-Emitting Devices.

A new class of fused heterocyclic tridentate ligand-containing alkynylgold(III) complexes with tunable emission color has been successfully designed and synthesized. Structural modification of the σ-donating fused heterocyclic alkynyl ligands, including substituted fluorene, carbazole, and triphenylamine, enables a large spectral shift of about 110 nm (ca. 3310 cm-1 ) that covers the green to red region to be realized with the same tridentate ligand-containing alkynylgold(III) complexes in solid-state thin films. Interestingly, the energy of the excimeric emission can be controlled by the rational design of the fused heterocyclic alkynyl ligands. Superior solution-processable organic light-emitting devices (OLEDs) with high external quantum efficiencies (EQEs) of 12.2, 13.5, 9.3, and 5.2 % were obtained with green, yellow, orange, and red emission. These high EQE values are comparable to those of the vacuum-deposited OLEDs based on structurally related alkynylgold(III) complexes.

Sky-Blue-Emitting Dendritic Alkynylgold(III) Complexes for Solution-Processable Organic Light-Emitting Devices.

A new class of tridentate ligand-containing cyclometalated gold(III) complexes featuring dendritic alkynyl ligands with carbazole moieties as dendrons and peripheral groups has been synthesized up to the third generation. High-performance solution-processable organic light-emitting devices (OLEDs) with maximum current efficiency of up to 23.7 cd A-1 and external quantum efficiency of up to 6.9% have been realized by a simple spin-coating technique. With the incorporation of bulky carbazole moieties to form higher generation dendrimers, the undesirable excimeric emission could be effectively reduced, allowing the fine-tuning of the emission color toward the blue region. This represents the first successful demonstration of sky-blue-emitting alkynylgold(III) complexes and its application in solution-processable OLEDs.

Versatile Design Strategy for Highly Luminescent Vacuum-Evaporable and Solution-Processable Tridentate Gold(III) Complexes with Monoaryl Auxiliary Ligands and Their Applications for Phosphorescent Organic Light Emitting Devices.

A new class of brightly blue-green-emitting arylgold(III) complexes has been synthesized, characterized, and applied as phosphorescent dopants in the fabrication of solution-processable and vacuum-deposited organic light-emitting devices (OLEDs). These arylgold(III) complexes can be readily synthesized by reacting the corresponding arylboronic acids with the gold(III) precursor complexes in a one-pot Suzuki-Miyaura coupling reaction. When compared to the structurally related alkynylgold(III) complex, arylgold(III) complexes 1 and 2 exhibit much higher photoluminescence quantum yields in solution state. High photoluminescence quantum yields are also observed in solid-state thin films. More importantly, the solid-state emission spectra show strong resemblance to those in solution, irrespective of the dopant concentration, leading to significant improvement in the color purity of the OLEDs by suppressing any excimer emission resulting from the π-stacking of the tridentate ligand. High performance solution-processable and vacuum-deposited blue-green-emitting OLEDs have also been realized, with maximum external quantum efficiencies of 7.3% and 14.7%, respectively, representing the first demonstration of efficient blue-green-emitting OLEDs based on cyclometalated arylgold(III) complexes.

Highly luminescent phosphine oxide-containing bipolar alkynylgold(iii) complexes for solution-processable organic light-emitting devices with small efficiency roll-offs.

We report the synthesis of alkynylgold(iii) complexes with an electron-transporting phosphine oxide moiety in the tridentate ligand and hole-transporting triarylamine moieties as auxiliary ligands to generate a new class of phosphine oxide-containing bipolar gold(iii) complexes for the first time. Such gold(iii) complexes feature high photoluminescence quantum yields of over 70% in 1,3-bis(N-carbazolyl)benzene thin films with relatively short excited-state lifetimes of less than 3.9 µs at a 20 wt% dopant concentration. Highly efficient solution-processable organic light-emitting devices have been prepared with superior current efficiencies of up to 51.6 cd A-1 and external quantum efficiencies of up to 15.3%. Notably, triplet-triplet annihilation has been significantly reduced, as exemplified by a very small efficiency roll-off of ∼1% at a practical brightness of 500 cd m-2.

Kaposiform hemangioendothelioma arising from the maxillary sinus: a case report.

Kaposiform hemangioendothelioma is a very infrequent, locally aggressive vascular neoplasm, characterized by fascicular spindle cell proliferation. It occurs almost exclusively in infants and adolescents, and is often associated with Kasabach-Merritt phenomenon. The tumor is predominantly located subcutaneously or in the deep soft tissue of the extremities and trunk, peritoneum, or retroperitoneum. However, this tumor can sometimes be located on the head and neck. We report a case of kaposiform hemangioendothelioma of the maxillary sinus in a 4-month-old female infant presenting with cheek swelling, thrombocytopenia, anemia, and disseminated intravascular coagulation. Sinus computed tomography presented an enhancing, bone-destructing tumor. Magnetic resonance images showed an uncommon appearance as mostly low signal intensity on T2-weighted images.