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A ferrocene‐based capsule is spontaneously and quantitatively formed in water by the assembly of bent amphiphiles carrying two ferrocene units. The disassembly and assembly of the new organometallic capsule, with a well‐defined and highly condensed ferrocene core, are demonstrated by chemical redox stimuli in a fully reversible fashion under ambient conditions. In contrast to previously reported multiferrocene assemblies, only the present capsule efficiently encapsulates typical organic/inorganic dyes as well as electron‐accepting molecules in water. As a result, unusual host‐guest charge‐transfer (CT) interactions, displaying relatively wide absorption bands in the visible to near‐infrared region (λ=650–1350 nm), are observed upon the encapsulation of acceptors (i.e. chloranil and TCNQ). The resultant encapsulation‐induced CT interactions can be released by a redox stimulus through the disassembly of the capsule. [ABSTRACT FROM AUTHOR]

A ferrocene‐based capsule is spontaneously and quantitatively formed in water by the assembly of bent amphiphiles carrying two ferrocene units. The disassembly and assembly of the new organometallic capsule, with a well‐defined and highly condensed ferrocene core, are demonstrated by chemical redox stimuli in a fully reversible fashion under ambient conditions. In contrast to previously reported multiferrocene assemblies, only the present capsule efficiently encapsulates typical organic/inorganic dyes as well as electron‐accepting molecules in water. As a result, unusual host‐guest charge‐transfer (CT) interactions, displaying relatively wide absorption bands in the visible to near‐infrared region (λ=650–1350 nm), are observed upon the encapsulation of acceptors (i.e. chloranil and TCNQ). The resultant encapsulation‐induced CT interactions can be released by a redox stimulus through the disassembly of the capsule. [ABSTRACT FROM AUTHOR]

π‐Conjugated aromatic polymers (πCAPs) are central components of functional materials yet suffer from insolubility without multiple covalent substituents on their backbones. We herein disclose a new strategy for the facile processing of unsubstituted heterocyclic πCAPs (i.e. poly(para‐phenylene‐2,6‐benzobisoxazole) and poly(benzimidazobenzo‐phenanthroline)), independent of the polymer length, via non‐covalent encircling with aromatic micelles, composed of bent aromatic amphiphiles, in water. The UV/Visible studies reveal that the efficiencies of the present encircling method are ≈10 to 50‐fold higher than those using conventional amphiphiles under the same conditions. The AFM and SEM analyses of the resultant aqueous polymer composites show that otherwise insoluble πCAPs form fine bundles (e.g. ≈1 nm in thickness) in the tubular aromatic micelles, through efficient π‐stacking interactions. In the same way, pristine poly(para‐phenylene) can be dissolved in water, displaying enhanced fluorescence (10‐fold), relative to the polymer solid. Two types of unsubstituted πCAPs are likewise co‐encircled in water, indicated by UV/Visible analysis. Importantly, aqueous processing of the encircled πCAPs into free‐standing single‐ or multicomponent films with submicrometer thickness is demonstrated through a simple filtration‐annealing protocol. [ABSTRACT FROM AUTHOR]

π‐Conjugated aromatic polymers (πCAPs) are central components of functional materials yet suffer from insolubility without multiple covalent substituents on their backbones. We herein disclose a new strategy for the facile processing of unsubstituted heterocyclic πCAPs (i.e. poly(para‐phenylene‐2,6‐benzobisoxazole) and poly(benzimidazobenzo‐phenanthroline)), independent of the polymer length, via non‐covalent encircling with aromatic micelles, composed of bent aromatic amphiphiles, in water. The UV/Visible studies reveal that the efficiencies of the present encircling method are ≈10 to 50‐fold higher than those using conventional amphiphiles under the same conditions. The AFM and SEM analyses of the resultant aqueous polymer composites show that otherwise insoluble πCAPs form fine bundles (e.g. ≈1 nm in thickness) in the tubular aromatic micelles, through efficient π‐stacking interactions. In the same way, pristine poly(para‐phenylene) can be dissolved in water, displaying enhanced fluorescence (10‐fold), relative to the polymer solid. Two types of unsubstituted πCAPs are likewise co‐encircled in water, indicated by UV/Visible analysis. Importantly, aqueous processing of the encircled πCAPs into free‐standing single‐ or multicomponent films with submicrometer thickness is demonstrated through a simple filtration‐annealing protocol. [ABSTRACT FROM AUTHOR]

π‐π Interactions are established as a powerful supramolecular tool, whereas the usability of CH‐π interactions has been rather limited so far. Here we present (i) selective binding of planar polyaromatics and (ii) effective isolation of planar metal complexes by a polyaromatic capsule, utilizing multiple CH‐π interactions. In the spheroidal cavity, one molecule of large and medium‐sized polyaromatic molecules (i. e. coronene and pyrene) is exclusively bound from mixtures bearing the same number of aromatic CH groups. Theoretical studies reveal that multiple host‐guest CH‐π interactions (up to 32 interactions) are the predominant driving force for the observed selectivity. In addition, one molecule of planar metal complexes (i. e. porphine and bis(acetylacetonato) Cu(II) complexes) is quantitatively bound by the capsule through aromatic and aliphatic CH‐π multi‐interactions, respectively. The ESR and theoretical studies demonstrate the isolation capability of the capsular framework and an unusual polar environment in the polyaromatic cavity. [ABSTRACT FROM AUTHOR]

Discrete, well-defined stacks of the polarized aromatic pyrene-4,5-dione (1) were assembled in the cavities of organic-pillared coordination cages (2). The number (n) of stacked guests depends on the pillar length, and up to quintuple stacks (n = 5) were observed when long (16.5 Å) organic pillar ligands were incorporated. As previously reported, pyrene-4,5-dione (1) assembles into infinite columnar stacks in the solid state, but the present work demonstrates that the polarized 1 has a strong propensity to stack in layers even in the absence of crystal packing effects. For n = 2 and 3 structures, crystallographic studies revealed that 1 stacks by π-π interactions in the cavity in such a way that a net dipole moment is canceled. These results emphasize the important role of dipole-dipole interactions as well as π-stacking interactions in the formation of columnar stacks of 1. [ABSTRACT FROM AUTHOR]

Short nucleotide fragments such as mono- and dinucleotides are generally unable to form stable hydrogen-bonded base pairs or duplexes in water. Within the hydrophobic pockets of enzymes, however, even short fragments form stable duplexes to transmit genetic information. Here, we demonstrate the efficient formation of hydrogen-bonded base pairs from mononucleotides in water through enclathration in the hydrophobic cavities of self-assembled cages. Crystallographic studies and 1H- and 15N-NMR spectroscopy clearly reveals pair-selective recognition of mononucleotides and the selective formation of an anti-Hoogsteen-type base pair in the cage's cavity. Within an analogous expanded cage, dinucleotides are also found to form a stable duplex in water. These results emphasize how hydrogen-bonded base pairing is amplified in a local hydrophobic area isolated from aqueous solution. [ABSTRACT FROM AUTHOR]

Self-assembled, hollow molecular structures are appealing as synthetic hosts for mediating chemical reactions. However, product binding has inhibited catalytic turnover in such systems, and selectivity has rarely approached the levels observed in more structurally elaborate natural enzymes. We found that an aqueous organopalladium cage induces highly unusual regioselectivity in the Diels-Alder coupling of anthracene and phthalimide guests, promoting reaction at a terminal rather than central anthracene ring. Moreover, a similar bowl-shaped host attains efficient catalytic turnover in coupling the same substrates (although with the conventional regiochemistry), most likely because the product geometry inhibits the aromatic stacking interactions that attract the planar reagents to the host. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes a new strategy to regulate multicomponent assembly from two kinds of pyridine-based ligands and cis-protected Pd(II) ions. The introduction of sterically hindered substituents to only one of the two ligands directs the complementary cis-coordination of the two lingads on the Pd(II) center, leading to the selective multicomponent assembly of two- and three-dimensional polynuclear Pd(II) complexes (e.g., square-, rectangular-, and trigonal prism-shaped molecules). [Copyright &y& Elsevier]

Herein reported is the highly selective [2 + 2] cross-photodimerization of olefins within a selfassembled coordination cage that acts as a molecular flask in an aqueous medium. An M[sub 6]L[sub 4] coordination nanocage that self-assembles from six Pd(ll) complexes and four tridentate ligands accommodates two different kinds of large olefin molecules such as acenaphthylene and 5-ethoxynaphthoquinone in a pairwise selective fashion. This prerequisite recognition mode makes possible the selective [2 + 2] crossphotodimerization of the olefins within the cavity. The reaction is extremely efficient in terms of reaction rate, stereoselectivity, and, most importantly, pairwise selectivity. Maieimide derivatives, which themselves are photochemically inactive under ordinary conditions, are also cross-dimerized with acenaphthylene or dibenzosuberenon quite efficiently. These results are in sharp contrast to those of common photodimerization in organic media, where the yields and selectivities are generally poor to moderate. The key step of the exclusive formation of the cross-dimers stems from the selective formation of ternary complexes before irradiation, which is governed by the size compatibility of the guests with the confined space of the cavity. [ABSTRACT FROM AUTHOR]

Self-assembly of pre-designed organic ligands with transition metal atoms is a powerful method for construction of novel supramolecular architectures. Particularly, various discrete 3-D hollow structures such as cages, cones, capsules and boxes have been obtained by multicomponent self-assembly of exo-multidentate ligands with cis-protected square planar metal complexes, [(L)M](NO3)2 (where L is ethylenediamine or 2,2′-bipyridine and M is Pd or Pt). Furthermore, these hollow structures act as molecular flasks to encapsulate guest molecules and regulate/promote specific reactions; for example, oligomerization of silanetriols and [2+2] intermolecular photodimerization of olefins. [Copyright &y& Elsevier]

Presents a cavity-directed synthesis of labile silanol oligomers within self-assembled coordination cages. Analysis on the regulation of chemical reactions by the hollow compounds; Observation of the x-ray crystallographic studies; Demonstration of the cavities direct the oligomerization reaction.

To develop new hybrid micelles with alkyl/polyaromatic core–shell structures, we synthesized umbrella‐shaped amphiphiles bearing a bent anthracene dimer with a linear alkyl chain (i.e. octyl and hexadecyl groups). The amphiphiles quantitatively assemble into spherical micelles (~2–3 nm in core diameter), possessing an alkylated cavity surrounded by a polyaromatic framework, in water. The alkylation significantly enhances the stability of the micellar structures against dilution (up to 9 μM) and heat (up to >120 °C). The highly condensed hexadecyl core of the hybrid micelle, as indicated by solvatochromic guest probes, displays increased uptake ability toward large alkylated metallodyes. Interestingly, efficient uptake of aromatic macrocycles (i.e. [n]cycloparaphenylenes) by the present micelle provides pseudorotaxane‐shaped host–guest composites with high emissivity (ΦF=up to 35 %). Internal multi‐alkylation of an aromatic micelle can thus successfully enhance its assembly stability/guest uptake functions. [ABSTRACT FROM AUTHOR]

To develop new hybrid micelles with alkyl/polyaromatic core–shell structures, we synthesized umbrella‐shaped amphiphiles bearing a bent anthracene dimer with a linear alkyl chain (i.e. octyl and hexadecyl groups). The amphiphiles quantitatively assemble into spherical micelles (~2–3 nm in core diameter), possessing an alkylated cavity surrounded by a polyaromatic framework, in water. The alkylation significantly enhances the stability of the micellar structures against dilution (up to 9 μM) and heat (up to >120 °C). The highly condensed hexadecyl core of the hybrid micelle, as indicated by solvatochromic guest probes, displays increased uptake ability toward large alkylated metallodyes. Interestingly, efficient uptake of aromatic macrocycles (i.e. [n]cycloparaphenylenes) by the present micelle provides pseudorotaxane‐shaped host–guest composites with high emissivity (ΦF=up to 35 %). Internal multi‐alkylation of an aromatic micelle can thus successfully enhance its assembly stability/guest uptake functions. [ABSTRACT FROM AUTHOR]

Three polarized aromatic guest molecules (pyrene-4,5-dione, 1) form a triple-layered stack in the box-shaped cavity of an organic pillared coordination cage in water. The cavity size strictly limits the number of stacked planar guests but does not restrict guest orientation, and thus enables the study of discrete stacks of polarized guests and their preferred conformations. Crystallographic study shows that the guest molecules in the cavity are rotated 1200 with respect to each other, canceling the net dipole moment rather than the local dipole moment. The unique conformation of a discrete, triple stack of 1 sharply contrasts to the standard head-to-tail conformation in infinite stacks of 1. [ABSTRACT FROM AUTHOR]

To develop a new type of synthetic saccharide clusters with changeable fluorescent colors, we herein designed a multisaccharide‐coated aromatic micelle. The new cluster forms in water through the quantitative assembly of bent polyaromatic amphiphiles bearing three mannose groups. The spherical assembly, with a 2 nm‐sized polyaromatic core and ca. 18 saccharide pendants, is stable even under high dilution conditions (up to 0.02 mM). The emission intensity and color of the saccharide cluster can be altered from moderate blue (ΦF=19 %) to strong red, orange, and green (ΦF up to 67 %) upon encapsulation of hydrophobic fluorescent dyes in water. Moreover, the present fluorescent clusters, both with and without the dyes, display selective interactions with mannose‐binding proteins in vitro. [ABSTRACT FROM AUTHOR]

To develop a new type of synthetic saccharide clusters with changeable fluorescent colors, we herein designed a multisaccharide‐coated aromatic micelle. The new cluster forms in water through the quantitative assembly of bent polyaromatic amphiphiles bearing three mannose groups. The spherical assembly, with a 2 nm‐sized polyaromatic core and ca. 18 saccharide pendants, is stable even under high dilution conditions (up to 0.02 mM). The emission intensity and color of the saccharide cluster can be altered from moderate blue (ΦF=19 %) to strong red, orange, and green (ΦF up to 67 %) upon encapsulation of hydrophobic fluorescent dyes in water. Moreover, the present fluorescent clusters, both with and without the dyes, display selective interactions with mannose‐binding proteins in vitro. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are excellent building blocks for the creation of two‐dimensional (2D) nanosheets. However, large PAHs tend to exhibit poor or no solubility in organic solvents and water. To overcome this issue, we employed water‐soluble micellar capsules consisting of V‐shaped amphiphilic molecules. Characteristic electrochemical behavior was observed in 0.1 m H2SO4 in the presence of the water‐soluble capsules containing PAHs, such as ovalene, circobiphenyl, and dicoronylene. Furthermore, under these conditions, PAHs were released from the capsules, resulting in the formation of a 2D adlayer of PAHs at the electrochemical interface. Finally, using electrochemical scanning tunneling microscopy, we demonstrate that our molecular containers based on water‐soluble molecular capsules allow the facile preparation of 2D PAH adlayers in addition to structurally controlling nanostructure formation on Au surfaces. Packaged and delivered: Water‐soluble molecular capsules consisting of V‐shaped amphiphiles were designed for the uptake of polycyclic aromatic hydrocarbons (PAHs). The PAHs were released from the molecular containers in 0.1 m H2SO4 at an electrochemical interface, thus enabling the facile preparation of 2D PAH adlayers on an Au surface with controlled nanostructure formation (see picture). [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are excellent building blocks for the creation of two‐dimensional (2D) nanosheets. However, large PAHs tend to exhibit poor or no solubility in organic solvents and water. To overcome this issue, we employed water‐soluble micellar capsules consisting of V‐shaped amphiphilic molecules. Characteristic electrochemical behavior was observed in 0.1 m H2SO4 in the presence of the water‐soluble capsules containing PAHs, such as ovalene, circobiphenyl, and dicoronylene. Furthermore, under these conditions, PAHs were released from the capsules, resulting in the formation of a 2D adlayer of PAHs at the electrochemical interface. Finally, using electrochemical scanning tunneling microscopy, we demonstrate that our molecular containers based on water‐soluble molecular capsules allow the facile preparation of 2D PAH adlayers in addition to structurally controlling nanostructure formation on Au surfaces. [ABSTRACT FROM AUTHOR]

The article reports on spin crossover, a phenomenon in which the electronic configuration of transition metal centers changes in response to external stimuli such as thermal, pressure, light and magnetic tones, by encapsulation. It says that encapsulation within synthetic hosts can induce spin crossover of square planar Nickel(II) and Carbon Monoxide (II) complexes. It adds that the constrictive environment within the hydrophobic host cavity enables one to establish intermolecular interactions.

The article examines the engineering stacks of aromatic rings by the interpenetration of self-assembled coordination cages. Aromatic towers consisting of seven to nine discretely stacked motifs with large aromatic molecules via the precisely controlled noncovalent interactions was constructed. Aromatic molecules exhibit unique electroconductive and photophysical properties when staked in layers.

This article focuses on the properties of mixed-valence cation radical dimer of tetrathiafulvalene (TTF) within a self-assembled cage. TTF is a strong electron donor and apt to generate the stable cation radical TTF upon oxidation. Electrochemical studies showed the unique behavior of accommodated TTF molecules. A striking feature was that the former oxidation wave around 200 mV could be resolved into two waves at the peak potentials of 152 and 304 mV. Through the accommodation in a self-assembled cage, the generation and observation of a mixed-valence dimer was made possible. It is particularly interesting that a weak dimeric species, which typically cannot be generated unless covalently linked, is observed in cage.

The article reports that stacking of planar transition-metal complexes via d-d interaction between the metal centers promises unique optical, electroconductive, and magnetic properties. Here, the authors report that simple and rather classical metal complexes, which have been never shown to form an intermolecular metal-metal bond, exhibit characteristic metal-metal interaction through accommodation within a coordination cage. It should be noted that the estimated Copper(II)-Copper(II) distance, as demonstrated in the article, is longer than the Platinum(II)-Platinum(II) distance determined by X-ray analysis.

This article focuses on endohedral clusterization of ten water molecules into a molecular ice within the hydrophobic pocket of a self-assembled cage. One of the most characteristic features of water molecules is their ability to make themselves rather hydrophobic by neutralizing their intrinsic high polarity by forming hydrogen-bonded networks. In particular, when they are in contact with a hydrophobic solute, hydrogen-bonded water networks spontaneously grow at the surface of the solute, often giving rise to stable hydrate complexes such as methane hydrate. This article reports that, within the hydrophobic cavity of a self-assembled coordination cage, an adamantanoid cluster is formed, which is termed molecular ice because this structure is the smallest unit of naturally occurring Ic-type ice. There are numerous examples of the crystallographic observation of water clusters in crystals, relatively few have been reported on the endohedral clusterization of water molecules within hollow discrete compounds, except for those in small host compounds.

To explore the intrinsic photoresponsible nature of coordination cage 1, authors examined the photoexcitation of the cage itself accommodating inert alkane guests. When adamantane-encapsulated complex 1⊃(2)4 was irradiated under aerobic conditions, authors found the regioselective oxidization of 2 at a tertiary carbon. An aqueous solution of 1⊃(2)4 complex was prepared by suspending powdered 2 in D20 solution of cage 1 and irradiated by a high-pressure mercury lamp in a Pyrex tube at room temperature for 30 mm under air.

This article presents a study on bimolecular recognition which is termed for host-guest interaction where a host recognizes two different guests in a single binding pocket. The two guests may or may not interact with each other, but their spatial orientation and the binding ratio are restricted by the host. Such a recognition process is essential to heterotopic allosteric binding and potentially applicable to, for example, simultaneous sensing of two substrates and chemical reactions between two different substrates. The two were termed two cases AND and OR bimolecular recognition by analogy with AND/OR logic gates.

Ring- and tube-shaped molecules like crown ethers and cyclodextrins play a fundamental role in supramolecular chemistry since their initial discovery. To date, numerous intriguing properties and reactivities have been reported based on their unique inner microenvironments. While inner spaces encircled by aliphatic and/or small aromatic frameworks have been heavily investigated, tubular structures that feature polyaromatic frameworks remained largely unexplored until 2010, despite their undisputable potential. Polyaromatic rings provide appealing photophysical and electrochemical properties and thus allow for the construction of new functional cylindrical nanospaces. This feature article describes the recent progress in the synthesis and application of short tubular molecules bearing multiple (≥3) polyaromatic rings (e.g., anthracene, pyrene, chrysene, and HBC). The polyaromatic tubes reported herein display characteristic properties such as strong fluorescent emission, a selective molecular binding ability, efficient host–guest energy transfer and open–closed structural transformations. [ABSTRACT FROM AUTHOR]

Micelles are a versatile class of molecular assemblies typically composed of aliphatic molecules with hydrophilic groups. Polyaromatic molecules with hydrophilic groups, on the other hand, usually do not assemble into micellar structures in water but rather form columnar, π-stacked architectures. This Minireview article focuses on the recent development of aqueous micellar nanostructures with multiple oligoarylene rods or polyaromatic panels. The new micelles with spherical polyaromatic shells, which we name 'aromatic micelles', serve as functional molecular flasks with superior binding abilities for medium to very large molecules in water. [ABSTRACT FROM AUTHOR]

A pentanuclear coordination complex assembled from any palladium(II) component and non-chelating ligands is hitherto unreported. The pentanuclear complex [Pd5( L1)5( L2)5](BF4)10, 1 reported here was prepared by the spontaneous complexation of [Pd(DMSO)4](BF4)2 with the non-chelating bidentate ligands 1,4-phenylenebis(methylene) diisonicotinate, L1 and 4,4′-bipyridine, L2 in a one-pot method at room temperature. The planar polycyclic complex 1 with outer diameters of ≈3 nm is termed as a 'molecular star' owing to its resemblance with a pentagram shape. Interim paths leading to the star were also probed to decipher related dynamics of the system. [ABSTRACT FROM AUTHOR]

Review: [50 refs. [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]

Development of porous materials capable of capturing volatile organic compounds (VOCs), such as benzene and its derivatives, with high efficiency, selectivity, and reusability is highly demanded. Here we report unusual vapor adsorption behavior toward VOCs by a new porous solid, composed of a polyaromatic capsule bearing a spherical nanocavity with subnano‐sized windows. Without prior crystallization and high‐temperature vacuum drying, the porous polyaromatic solid exhibits the following five features: vapor adsorption of benzene over cyclohexane with 90 % selectivity, high affinity toward o‐xylene over benzene and toluene with >80 % selectivity, ortho‐selective adsorption ability (>50 %) from mixed xylene isomers, tight VOCs storage even under high temperature and vacuum conditions, and at least 5 times reusability for xylene adsorption. The observed adsorption abilities are accomplished at ambient temperature and pressure within 1 h, which has not been demonstrated by organic/inorganic porous materials reported previously. [ABSTRACT FROM AUTHOR]

Metallophthalocyanines (MPcs) are very useful pigments but scarcely soluble without appropriate functional groups in common solvents. Herein, we report that bent polyaromatic amphiphiles act as excellent solubilizing reagents for nonfunctionalized MPcs and larger MPc derivatives (e.g., CuPc, perhalogenated CuPcs, Cu-naphthalocyanine, CuPc polymers, and double-decker MPcs) in neutral water upon encapsulation. The resultant MPc nanocomposites display high stability towards heat and pH change. More importantly, the encapsulated MPcs can be released by simple protocols under mild conditions both into a bulk solvent and onto glass or polymer plates. [ABSTRACT FROM AUTHOR]

[Display omitted] • Coordination receptors for biomolecules in water are highlighted. • Representative examples of aqueous covalent receptors are included. • Selective binding of six different biomolecule classes is described. • Binding ratio, order, constant, and mechanism are discussed in detail. • Advantages and potential applications of synthetic receptors are presented. Mimicking the selective binding ability of biological receptors, providing confined protein pockets, is a long-standing challenge for synthetic chemists. Preparation of synthetic receptors using bio-related subunits has been intensively studied so far. Unfortunately, the majority of such bio-inspired receptors display only poor to moderate binding selectivity toward biomolecules in water. To stimulate further developments in this field, the present review highlights recent progress of capsular and cage-type polyaromatic/aromatic receptors, mainly formed via coordination bonds, with high selectivity toward various biomolecules, i.e., i) amino acids and their oligomers, ii) fatty and lactic acids, iii) carbohydrates, iv) alkaloids and nucleosides/nucleotides, v) steroids, and vi) terpenes, in aqueous media. The observed selectivities stem from multiple receptor-biomolecule interactions in the confined artificial cavities, as evidenced by NMR, MS, ITC, theoretical, and/or X-ray crystallographic analyses. Representative examples of previous synthetic bioreceptors, composed of aliphatic and/or small aromatic frameworks, are also included for comparison. [ABSTRACT FROM AUTHOR]

Host–guest assemblies of a designed 1,4-bis(diarylamino)naphthalene and V-shaped aromatic amphiphiles consisting of two pentamethylbenzene moieties bridged by an m -phenylene unit bearing two hydrophilic side chains emerged as highly reducing photoredox catalysis systems in water. An efficient demethoxylative hydrogen transfer of Weinreb amides has been developed. The present supramolecular strategy permits facile tuning of visible-light photoredox catalysis in water. [ABSTRACT FROM AUTHOR]

To explore new cavity functions, we herein employed cis‐trans stereoisomers with a N=N, C=C, or C=N unit as guest indicators for a polyaromatic capsule. Thanks to the rigid, spherical cavity with a diameter of ∼1 nm, azobenzene and stilbene derivatives are quantitatively encapsulated by the capsule with 100 % cis‐selectivity in water. The isomerization of the cis‐azo compound is suppressed against heat and light in the cavity, due to the confinement effect. Furthermore, C,N‐diphenyl imine derivatives are quantitatively encapsulated by the capsule in water and adopt an otherwise unstable cis‐form. The polyaromatic cavity suppresses the hydrolysis of the imines in water, even at elevated temperature, due to the shielding effect. Accordingly, the properties of the cis‐trans isomers could be largely altered through supramolecular manipulation. [ABSTRACT FROM AUTHOR]

An M2L4 coordination capsule or an M2L2 coordination tube was selectively formed by the combination of HgII hinges and bent bispyridine ligands. The two structures reversibly interconvert at room temperature in response to modulation of the metal-to-ligand ratio and exhibit different host-guest interaction behavior. The capsule alone encapsulates large spherical molecules, fullerenes C60 and C70, and the bound guests are released upon capsule-to-tube transformation by the simple addition of metal ions. [ABSTRACT FROM AUTHOR]

An M2L4 coordination capsule or an M2L2 coordination tube was selectively formed by the combination of HgII hinges and bent bispyridine ligands. The two structures reversibly interconvert at room temperature in response to modulation of the metal-to-ligand ratio and exhibit different host-guest interaction behavior. The capsule alone encapsulates large spherical molecules, fullerenes C60 and C70, and the bound guests are released upon capsule-to-tube transformation by the simple addition of metal ions. [ABSTRACT FROM AUTHOR]

Catalyst‐ and reagent‐free reactions are powerful tools creating various functional molecules and materials. However, such chemical bonds are usually hydrolysable or require specific functional groups, which limits their use in aqueous media. Herein, we report the development of new amphiphiles through the Staudinger reaction. Simple mixing of chlorinated aryl azide with a hydrophilic moiety and various triarylphosphines (PAr3) gave rise to azaylide‐based amphiphiles NPAr3, rapidly and quantitatively. The obtained NPAr3 formed ca. 2 nm‐sized spherical aggregates (NPAr3)n in water. The hydrolysis of NPAr3 was significantly suppressed as compared with those of non‐chlorinated amphiphiles nNPAr3. Computational studies revealed that the stability is mainly governed by the decrease in LUMO around the phosphorus atom owing to the o‐substituted halogen groups. Furthermore, hydrophobic dyes such as Nile red and BODIPY were encapsulated by the spherical aggregates (NPAr3)n in water. [ABSTRACT FROM AUTHOR]

Catalyst‐ and reagent‐free reactions are powerful tools creating various functional molecules and materials. However, such chemical bonds are usually hydrolysable or require specific functional groups, which limits their use in aqueous media. Herein, we report the development of new amphiphiles through the Staudinger reaction. Simple mixing of chlorinated aryl azide with a hydrophilic moiety and various triarylphosphines (PAr3) gave rise to azaylide‐based amphiphiles NPAr3, rapidly and quantitatively. The obtained NPAr3 formed ca. 2 nm‐sized spherical aggregates (NPAr3)n in water. The hydrolysis of NPAr3 was significantly suppressed as compared with those of non‐chlorinated amphiphiles nNPAr3. Computational studies revealed that the stability is mainly governed by the decrease in LUMO around the phosphorus atom owing to the o‐substituted halogen groups. Furthermore, hydrophobic dyes such as Nile red and BODIPY were encapsulated by the spherical aggregates (NPAr3)n in water. [ABSTRACT FROM AUTHOR]

An aromatic oligomer micelle, featuring both high stability and high uptake ability, was quantitatively formed in water from amphiphilic oligomers, composed of three bent polyaromatic amphiphiles connected alternately by two hydrophilic chains. The well‐defined micelle, with a diameter of ca. 2 nm, remains intact even under highly diluted conditions (ca. 3 μM) and at elevated temperature (>130 °C), due to the polyaromatic chelate effect. The thermodynamic studies reveal that large enthalpic gain (ΔH=−110 kJ mol−1) is the key for the micelle formation. The oligomer micelle selectively encapsulates unsubstituted oligothiophenes (≥4‐mer) to a high degree and the resultant, aqueous host‐guest complexes display unusual emission derived from the multiply stacked oligomers. Furthermore, facile uptake and release of unsubstituted polythiophenes can be achieved using the oligomer micelle. [ABSTRACT FROM AUTHOR]

An aromatic oligomer micelle, featuring both high stability and high uptake ability, was quantitatively formed in water from amphiphilic oligomers, composed of three bent polyaromatic amphiphiles connected alternately by two hydrophilic chains. The well‐defined micelle, with a diameter of ca. 2 nm, remains intact even under highly diluted conditions (ca. 3 μM) and at elevated temperature (>130 °C), due to the polyaromatic chelate effect. The thermodynamic studies reveal that large enthalpic gain (ΔH=−110 kJ mol−1) is the key for the micelle formation. The oligomer micelle selectively encapsulates unsubstituted oligothiophenes (≥4‐mer) to a high degree and the resultant, aqueous host‐guest complexes display unusual emission derived from the multiply stacked oligomers. Furthermore, facile uptake and release of unsubstituted polythiophenes can be achieved using the oligomer micelle. [ABSTRACT FROM AUTHOR]

A nanocapsule composed of multiple carbazole panels (ca. 12 panels) was quantitatively generated from bent carbazole‐based amphiphiles in water. Unlike previously reported macrocycles and coordination cages bearing several carbazole panels, the resultant nanocapsule displays enhanced emissivity and improved electrochemical stability as compared with the monomeric amphiphile. The spectroscopic properties of substituted coumarin and boron‐dipyrromethene dyes can be modulated upon encapsulation by the nanocapsule in water. In the cavity, a highly blue‐shifted absorption band is observed from largely twisted coumarin dyes and two absorption bands are found from boron‐dipyrromethene dimers stacked in an unusual L‐shaped fashion. Moreover, the encapsulated dimers exhibit unique excimer‐like emission. [ABSTRACT FROM AUTHOR]

A nanocapsule composed of multiple carbazole panels (ca. 12 panels) was quantitatively generated from bent carbazole‐based amphiphiles in water. Unlike previously reported macrocycles and coordination cages bearing several carbazole panels, the resultant nanocapsule displays enhanced emissivity and improved electrochemical stability as compared with the monomeric amphiphile. The spectroscopic properties of substituted coumarin and boron‐dipyrromethene dyes can be modulated upon encapsulation by the nanocapsule in water. In the cavity, a highly blue‐shifted absorption band is observed from largely twisted coumarin dyes and two absorption bands are found from boron‐dipyrromethene dimers stacked in an unusual L‐shaped fashion. Moreover, the encapsulated dimers exhibit unique excimer‐like emission. [ABSTRACT FROM AUTHOR]

Septuple columnar stacks of large aromatic molecules with solubilizing side chains have been synthesized via one-step multicomponent self-assembly. At increased concentrations in aqueous solution, m x n aggregates of aromatic stacks form. The simple addition of water induces lyotropic liquid-crystalline mesophases. [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]

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]

Selective recognition of natural fatty acids is intrinsically difficult owing to the long, flexible, and poorly interactive hydrocarbon chains. Inspired by biological recognition systems, we herein demonstrate the exclusive binding of a monounsaturated fatty acid by an artificial polyaromatic receptor from a mixture of the unsaturated and corresponding saturated substrates (i.e. oleic and stearic acids) in water. The selectivity stems from multiple CH–π/π–π interactions between the host framework and the guest in its roughly coiled conformation. Moreover, competitive binding experiments elucidate higher binding affinities of the receptor for oligo‐ and polyunsaturated fatty acids (e.g. α‐linolenic acid and EPA). Within the receptor, the biosubstrates are remarkably stabilized against air, light, and heat owing to the polyaromatic shielding effect. [ABSTRACT FROM AUTHOR]

Selective recognition of natural fatty acids is intrinsically difficult owing to the long, flexible, and poorly interactive hydrocarbon chains. Inspired by biological recognition systems, we herein demonstrate the exclusive binding of a monounsaturated fatty acid by an artificial polyaromatic receptor from a mixture of the unsaturated and corresponding saturated substrates (i.e. oleic and stearic acids) in water. The selectivity stems from multiple CH–π/π–π interactions between the host framework and the guest in its roughly coiled conformation. Moreover, competitive binding experiments elucidate higher binding affinities of the receptor for oligo‐ and polyunsaturated fatty acids (e.g. α‐linolenic acid and EPA). Within the receptor, the biosubstrates are remarkably stabilized against air, light, and heat owing to the polyaromatic shielding effect. [ABSTRACT FROM AUTHOR]