A Conjugated Carboranyl Main Chain Polymer with Aggregation-Induced Emission in the Near-Infrared.

Materials exhibiting aggregation-induced emission (AIE) are both highly emissive in the solid state and prompt a strongly red-shifted emission and should therefore pose as good candidates toward emerging near-infrared (NIR) applications of organic semiconductors (OSCs). Despite this, very few AIE materials have been reported with significant emissivity past 700 nm. In this work, we elucidate the potential of ortho-carborane as an AIE-active component in the design of NIR-emitting OSCs. By incorporating ortho-carborane in the backbone of a conjugated polymer, a remarkable solid-state photoluminescence quantum yield of 13.4% is achieved, with a photoluminescence maximum of 734 nm. In contrast, the corresponding para and meta isomers exhibited aggregation-caused quenching. The materials are demonstrated for electronic applications through the fabrication of nondoped polymer light-emitting diodes. Devices employing the ortho isomer achieved nearly pure NIR emission, with 86% of emission at wavelengths longer than 700 nm and an electroluminescence maximum at 761 nm, producing a significant light output of 1.37 W sr-1 m-2.

Doubly Encapsulated Perylene Diimides: Effect of Molecular Encapsulation on Photophysical Properties.

Intermolecular interactions play a fundamental role on the performance of conjugated materials in organic electronic devices, as they heavily influence their optoelectronic properties. Synthetic control over the solid state properties of organic optoelectronic materials is crucial to access real life applications. Perylene diimides (PDIs) are one of the most highly studied classes of organic fluorescent dyes. In the solid state, π-π stacking suppresses their emission, limiting their use in a variety of applications. Here, we report the synthesis of a novel PDI dye that is encapsulated by four alkylene straps. X-ray crystallography indicates that intermolecular π-π stacking is completely suppressed in the crystalline state. This is further validated by the photophysical properties of the dye in both solution and solid state and supported by theoretical calculations. However, we find that the introduction of the encapsulating "arms" results in the creation of charge-transfer states which modify the excited state properties. This article demonstrates that molecular encapsulation can be used as a powerful tool to tune intermolecular interactions and thereby gain an extra level of control over the solid state properties of organic optoelectronic materials.

Delineation of the etiology of a mass-like echo density in the left ventricle using three-dimensional transthoracic echocardiography.

Live/real time three-dimensional transthoracic echocardiography (3DTTE) provides an incremental value in the delineation of various cardiac pathologies. In this study, two-dimensional transthoracic echocardiography (2DTTE) of a 56-year-old patient showing a prominent echo density suggestive of a mass in the left ventricle probably attached to the ventricular side of the anterior mitral leaflet, is reported. Systematic cropping of the 3DTTE dataset showed the mass to be a calcified mitral strut chord viewed in cross section. This is well visualized in the accompanying movie clip. This case highlights the advantage of 3DTTE in which the whole of the ventricle including the mitral valve apparatus is captured in the dataset facilitating cropping at any desired angulation.