The presence of anomalous chirality in a roll of graphitic carbon sheets has been recognized since the discovery of carbon nanotubes, which are becoming available in higher quantities through the isolation of chiral single-wall congeners with high purity. Exploration of the properties arising from cylinder chirality is expected to expand the scope of tubular entities in the future. By studying molecular fragments of helical carbon nanotubes, we herein reveal interesting properties that arise from this chirality. The chirality of nanoscale cylinders resulted in chirality of larger dimensions in the form of a double-helix assembly. Cylinder chirality in solution gave rise to a large dissymmetry factor of metal-free entities in circular polarized luminescence. Theoretical investigations revealed the pivotal role of cylindrical shapes in enhancing magnetic dipole transition moments to yield extreme rotatory strength. Unique effects of cylinder chirality in this study may prompt the development of tubular entities, for instance, toward chiroptical applications.
A method for the modular synthesis of aromatic hydrocarbon macrocycles has been developed for base materials in single-layer organic light-emitting devices. The method with Ir-catalyzed direct C-H borylation and Suzuki-Miyaura coupling was concise and scalable, which allowed for a gram-scale preparation of aromatic hydrocarbon macrocycles that have bulky substituents at the periphery. The new arylated hydrocarbon macrocycles enabled a quantitative electro-optical conversion in organic light-emitting devices with a phosphorescent emitter, which is, notably, in a single-layer architecture consisting of two regions of doped and undoped materials. The highest external quantum efficiencies reached 24.8%, surpassing those of previous hydrocarbon base materials.
ZuschriftenScheme 2. Substrate scope.[a] The reactions were conducted using 0.5 mmol of the amides 1.Y ields of the isolated alcohols 2 and amines 3 are given.[b] The reaction was conducted using 5equiv of NaH, 2equiv of ZnI 2 and 2equiv of NaI.[c] The reaction was conducted using 7equiv of NaH and 3.5 equiv of ZnCl 2 .[d] 1aj > 98 %ee; 2aj > 97 %ee; 3aj > 98 % ee as measured by the Mosher method (see the Supporting Information).[e] Amine 3ak was formed in 35 %yield. [f]Amine 3al was formed in 31 %yield. Bn = benzyl, Ph = phenyl, TIPS = triisopropylsilyl.Scheme 5. DFT calculations for model reactions of benzamide with (ZnH 2 ) 2 or (ZnHCl) 2 species. Energy changes and bond lengths at the wB97XD/SDD&6-31 + G* (scrf = smd, THF) level of theory are shown in kcal mol À1 and ,respectively.
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