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Herein, we report the synthesis and electrochemical and photophysical properties of aromatic hydrocarbons having one or two dimesitylborylethynyl peripherals. The mono‐ (1) and diboryl compounds (2), readily prepared by nucleophilic substitution reaction, are fairly stable to air and moisture in the solid state. The inserted ethynediyl (C≡C) spacer cancels the steric hindrance between the bulky dimesitylboryl groups and aromatic rings, leading to effective π conjugation over the B−C≡C−Ar linkages, as revealed by cyclic voltammetry. Despite the small structural differences, the photophysical properties of the benzene, naphthalene, and anthracene derivatives are different. Virtually no emission was observed from the benzene derivatives, whereas the anthracene derivatives emitted with high quantum yields both in solution and in the solid state. Notably, the naphthalene derivatives showed aggregation‐induced emission behavior. Unlike the common sterically congested triarylborane derivatives reported so far, the anthracene derivatives showed π–π*‐type absorption and emission bands, which derive from efficient intramolecular orbital interactions between the boron centers and anthracene moieties, as supported by DFT calculations. As a result, the dimesitylborylethynyl substituents effectively lower the LUMO levels of the aromatic hydrocarbon parts, whereas the HOMO levels are almost unaffected, thereby leading to materials with controllable HOMO–LUMO gaps. [ABSTRACT FROM AUTHOR]

To gain insight into the host functions of a nanocavity encircled by both polyaromatic panels and heteroatoms, nitrogen‐doped polyaromatic capsules were successfully synthesized from metal ions and pyridine‐embedded, bent anthracene‐based ligands. The new capsules display unique host–guest interactions in the isolated cavities, which are distinct from those of the undoped analogues. Besides the inclusion of Ag+ ions, the large absorption change of fullerene C60 and altered emission of a BODIPY dimer are observed upon encapsulation by the present hosts. Moreover, the N‐doped capsule exhibits specific binding ability toward progesterone and methyltestosterone, known as a natural female and synthetic male hormone, respectively, in water. [ABSTRACT FROM AUTHOR]

A rigid tribranched scaffold with three anthracene panels was synthesized using a stereocontrolled 1,3,5-triphenylbenzene core. Grinding a mixture of the rigid scaffold and perylene leads to the quantitative formation of a spherical assembly containing stacked perylene molecules in water. The wrapped perylenes exhibit unusual Y-type excimer-like emission (λmax = ∼500 nm) at room temperature. In contrast, an analogous assembly from a flexible tribranched scaffold and perylene shows E-type emission (λmax = ∼610 nm) from the wrapped perylenes under the same conditions. [ABSTRACT FROM AUTHOR]

A V-shaped bisanthracene derivative with three butyl groups formed two types of emissive solids that display bluish green and blue fluorescence (ΦF=72 and 32 %, respectively), depending on the preparation conditions. The crystal and powder X-ray analyses reveal that the highly emissive solid adopts a head-to-head arrangement with discrete stacks of the anthracene moieties, whereas the moderately emissive solid adopts a head-to-tail arrangement without the stacks. The obtained molecular arrangements are transformed by thermal stimuli accompanying the change in fluorescence. Furthermore, large enhancements of dye emissions (12-45-fold) through highly efficient host-guest energy transfer were achieved in the solid state by adding minute amounts of various fluorescent dyes (e.g. rubrene and Nile red) to the V-shaped compound. [ABSTRACT FROM AUTHOR]

Nanocarbons are synthetic carbon-rich compounds with polyaromatic frameworks that have lately attracted attention as emerging functional materials. However, their extreme hydrophobicity and aggregation peculiarity, besides their shape and size diversities, precluded their study in solution, especially in 'green' water. More convenient and general solubilizing methods of nanocarbon frameworks are required by using non-covalent supramolecular interactions. Here we report a protocol for solubilizing a wide range of nanocarbons, that is, fullerenes (C60, C70, C84, and C120), polyarenes (tetracene, pentacene, perylene, coronene, and hexabenzocoronene), and carbon nanotubes (single-walled and multi-walled CNTs), in water through manual grinding with V-shaped polyaromatic amphiphiles. The obtained aqueous nanocomposites are composed of nanocarbons encircled by the polyaromatic frameworks of the amphiphiles through multiple aromatic-aromatic interactions. Notably, the encapsulated photosensitive nanocarbons, such as tetracene, pentacene, and fullerene dimer, exhibit unusual stability toward UV/Vis light. [ABSTRACT FROM AUTHOR]

Anisotropic expansion of a spherical M2L4 coordination capsule through the elongation of the ligand led to a new M2L'4 capsule. The expanded capsule provides an elliptical cavity encircled by polyaromatic frameworks with large openings and thereby can encapsulate elliptical fullerene C70 and monofunctionalized fullerene C60 in high yields. In addition, selective formation of a new M2L2L'2 capsule occurs by mixing the original M2L4 and expanded M2L'4 capsules in a 1:1 ratio upon addition of C60 or monofunctionalized C60 as a template molecule. [ABSTRACT FROM AUTHOR]

Functionalization of the polyaromatic shell of a micelle-like molecular capsule was accomplished by simple functionalization of the amphiphilic subunits composed of a bent bis-anthracene framework and two trimethylammonium groups. In aqueous solutions, functionalized subunits assemble spontaneously and quantitatively into spherical capsules providing anthracene shells with external diameters of 2-3 nm through hydrophobic and aromatic-aromatic interactions. The shape and size of the functionalized capsules remain similar to the original, but the emissive intensities increase significantly (up to 5-fold) by attaching cyano or phenylethynyl groups. Furthermore, the shell-functionalization drastically enhances the host-guest photophysical properties (up to 8-fold) in the cavities of the capsules, as estimated by emission intensities from the encapsulated fluorescent dyes. [ABSTRACT FROM AUTHOR]

A fluorescent macrocycle containing four anthracene panels linked by meta-phenylene spacers and amino hinges was synthesized. The macrocycle adopts a twisted, compressed conformation that places embedded anthracene fluorophores in close contact. Emission from the convoluted macrocycle is highly solvatochromic and significantly enhanced as compared with that of the partial structures. [ABSTRACT FROM AUTHOR]

Atroposelective formation: Selective formation of a molecular capsule was demonstrated from an amphiphilic cis‐atropisomer bearing three anthracene rings and four sulfonate groups through hydrophobic and aromatic–aromatic interactions. The dimeric capsule binds small guest molecules; the resultant host–guest complexes exhibit ground‐state charge‐transfer interactions accompanied by changes in host emission. [ABSTRACT FROM AUTHOR]

This article reports that an M2L4 molecular capsule is capable of encapsulating various neutral molecules in quantitative yields. The capsule was obtained as a single product by mixing a small number of components; two PdII ions and four bent bispyridine ligands containing two anthracene panels. Detailed studies of the host capability of the PdII-linked capsule revealed that spherical (e.g., paracyclophane, adamantanes, and fullerene C60), planar (e.g., pyrenes and triphenylene), and bowl-shaped molecules (e.g., corannulene) were encapsulated in the large spherical cavity, giving rise to 1:1 and 1:2 host-guest complexes, respectively. The volume of the encapsulated guest molecules ranged from 190 to 490 Å3. Within the capsule, the planar guests adopt a stacked-dimer structure and the bowl-shaped guests formed an unprecedented concave-to-concave capsular structure, which are fully shielded by the anthracene shell. Competitive binding experiments of the capsule with a set of the planar guests established a preferential binding series for pyrenes≈phenanthrene>triphenylene. Furthermore, the capsule showed the selective formation of an unusual ternary complex in the case of triphenylene and corannulene. [ABSTRACT FROM AUTHOR]

Combining meta-triphenylamine or triphenylphosphine with three anthracene fluorophores gives rise to fluorescent non-planar triskelions 1 and 2. The emissive properties of 1 are highly solvatochromic, yielding blue to pale green and even pale yellow fluorescence, whereas the blue emission of 2 is solvent-insensitive. Anthracene trimers 1 and 2 are both emissive in the solid state, displaying yellow and pale green fluorescence, respectively, with moderate quantum yields. [ABSTRACT FROM AUTHOR]

An isostructural series of M2L4 molecular capsules quantitatively self-assembled from two MII ions (M=Zn, Cu, Pt, Pd, Ni, Co, and Mn) and four bent ligands with embedded anthracene fluorophores. X-ray crystallographic analysis (for M=Zn, Cu, Ni, and Pd) confirmed the formation of closed-shell structures in which the large interior cavities inside the molecular capsules (about 1 nm) were shielded by eight anthracene panels. Analysis of the ZnII and CuII structures showed the inclusion of an unusual triad guest cluster; four MeCN molecules, one water molecule, and one CF3SO3− ion were located inside the cavities. Full characterization by NMR spectroscopy and MS (ESI-TOF) demonstrated that the molecular capsules were quite stable and persist in solution. The fluorescence properties of the isostructural capsules were strongly dependent on the identity of the metal species: the ZnII capsule emitted strong blue fluorescence with a high quantum yield ( Φ=0.8), in sharp contrast to the weakly emissive NiII and MnII capsules and the completely non-emissive PdII, PtII, and CoII capsules. On the other hand, the CuII capsule exhibited solvatochromism and solvent-dependent emission behavior; blue emission of the capsule was 'on' in DMSO but 'off' in MeCN. [ABSTRACT FROM AUTHOR]

M2L4molecular capsules self-assembled from M(ii) ions (where M = Zn, Ni, and Pd) and bent bidentate ligands constructed from anthracene fluorophores. The Ni(ii) and Zn(ii) capsules exhibited weak to strong blue emission unlike traditional Pd(ii) cages and capsules. [ABSTRACT FROM AUTHOR]

Three anthracene rings connected by m-phenylene spacers with hydroxy groups generate isolable trans- and cis-atropisomers whose interconversion is solvent sensitive and can be activated at room temperature by an external stimulus (base). [ABSTRACT FROM AUTHOR]

A new protocol for solubilizing various nanocarbons such as spherical fullerenes Cn (e.g., n=60, 70, and 84), planar polyarenes (e.g., tetracene, coronene, and hexabenzocoronene), and cylindrical carbon nanotubes (e.g., SWCNTs and MWCNTs) in water through manual grinding with V ‐ shaped polyaromatic amphiphiles is described in the Full Paper by K. Kondo and M. Yoshizawa et al. on page 12741 ff. The obtained aqueous nanocomposites are composed of nanocarbons encircled by the polyaromatic panels of the amphiphiles through multiple aromatic – aromatic interactions. Notably, the encapsulated photosensitive nanocarbons, such as tetracene and fullerene dimer C120 , exhibit high stability toward light. [ABSTRACT FROM AUTHOR]

A new M2L4 molecular capsule with an aromatic shell was prepared using two Pd(II) ions and four bisanthracene ligands. The self-assembled capsule possesses a cavity with a diameter of ~1 nm that can encapsulate medium-sized spherical and planar molecules as well as a very large molecule (C60) in quantitative yields. The encapsulated guests are fully segregated and shielded from the external environment by the large anthracene panels. [ABSTRACT FROM AUTHOR]