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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]

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]

Transesterification reactions of acyclic oligoether esters E3-E10 with metal alkoxides were accelerated upon noncovalent complexation of the esters with metal ions. In the reaction of monovalent alkaline metal alkoxides, CH3ONa and CH3OK, plots of the observed rate constants kobs with respect to the chain length of E3-E10 showed selective acceleration of the transesterification. Compared with the shortest E3, which can hardly bind metal ion, 4.3- and 6.6-fold accelerations in the maxima were achieved in the combinations of E5/CH3ONa and E6/CH3OK, respectively. Supramolecular intermediate complex could be spectrometrically visualized by ESI-FT-ICR-MS in the course of reaction. Kinetic experiments, together with structural analyses by means of NMR, mass spectrometry, and DFT calculations of the intermediate complexes, indicate that a size-fit complex of host substitute with alkali metal ion allows strong electron withdrawing due to the close contact of the carbonyl oxygen to the metal ion, resulting in the selective rate enhancement of the reaction, while in the reaction of E3-E10 with a divalent alkaline earth metal alkoxide, (CH3CH2O)2Ba, the kobs values increased stepwise with elongation of the side arm to attain an dramatic large acceleration. In comparison with the kobs of E3, 4610-fold acceleration was achieved in the reaction of E10. The double activation of the host substrate and guest counter nucleophile at once brings about this extraordinary rate acceleration. The strong wrapping complexation of long oligoether ester with barium ethoxide allows for the effective electron withdrawal from the ester carbonyl group (host activation) as well as separation of the accompanying guest alkoxide anions (guest activation). [ABSTRACT FROM AUTHOR]

Enantioselective alcoholysis of σ-symmetric cyclic dicarboxylic anhydrides with benzyl alcohol catalyzed by a chiral bifunctional sulfonamide was achieved in up to 98% ee at 5 mol% loading. [ABSTRACT FROM AUTHOR]

The article focuses on a research on organocatalytic oxidative cleavage method of carbon-carbon double and triple bonds. The method utilizes iodomesitylene as an organocatalyst which generates m-chloroperbenzoic acid as a terminal oxidant under metal-free conditions. The methodology has been supported by chemical reactions and charts. The results show that iodomesitylene serves as the most effective organocatalyst. The results reflect the cleavage method as more eco-friendly than ozonolysis.

Highlights: [•] Polysulfones with –O(CH2)3SO3H side chains were synthesized. [•] Ni- and Pd-promoted polycondensation gave the polymers. [•] Crosslinking of the polymer with 1,4-benzenedimethanol. [•] The cross-linked polymer film showed proton conductivity of 0.26Scm−1. [ABSTRACT FROM AUTHOR]

Abstract: We investigated the fixation of CO2 by several amidines in solution and found that simple monocyclic amidines fixed CO2 under dry conditions to quantitatively afford the corresponding bicarbonates through hydrolysis of the zwitterionic adducts by adventitious water. In contrast, linear amidines did not form the bicarbonates under the same conditions, while 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) could not effectively trap CO2. The CO2 fixed by the monocyclic amidines was quantitatively released by argon bubbling at a temperature as low as 60 °C. The CO2 fixation–release process could be repeated several times without loss of the high efficiency. [Copyright &y& Elsevier]

In this paper, we report hemithioketal formation of diphenylpropanetrione (DPPT) with thiols and their recovery. Addition of thiols to the central carbonyl group occurred readily at ambient temperature to provide the thiol adducts of DPPT ( DPPT – thiols ), which has a hemithioketal structure. On the other hand, oxidizing DPPT – thiols with an oxidation reagent enabled successful recovery of DPPT, which indicated the reversible nature of this system. [ABSTRACT FROM AUTHOR]

In this paper, we report reversible capture and release of aromatic amines by diphenylpropanetrione ( DPPT ). Addition of aromatic amines to the central carbonyl group occurred readily at ambient temperature to provide the aromatic amine adducts of DPPT ( DPPT–aromatic amines ), which has a hemiaminal structure. On the other hand, washing a solution of DPPT–aromatic amine with diluted hydrochloric acid (HCl) enabled successful recovery of DPPT to demonstrate the reversible nature of this system. [ABSTRACT FROM AUTHOR]

Abstract: Dibromopyridines or dibromopyridone with –(CH2)m–SO3Na group(s) has been prepared via the reactions of the corresponding dibromopyridines with –OH and –NH2 groups with sultone. These compounds were converted into polymers with the –(CH2)m–SO3H groups via organometallic polycondensation. The polymer showed proton conducting properties and high stability toward oxidation. [Copyright &y& Elsevier]

Abstract: Swine-origin influenza A virus has caused pandemics throughout the world and influenza A is regarded as a serious global health issue. Hence, novel drugs that will target these viruses are very desirable. Influenza A expresses an RNA polymerase essential for its transcription and replication which comprises PA, PB1, and PB2 subunits. We identified potential novel anti-influenza agents from a screen of 34 synthesized phenethylphenylphthalimide analogs derived from thalidomide (PPT analogs). For this screen we used a PA endonuclease inhibition assay, a PB2 pathogenicity-determinant domain-binding assay, and an anti-influenza A virus assay. Three PPT analogs, PPT-65, PPT-66, and PPT-67, were found to both inhibit PA endonuclease activity and retard the growth of influenza A, suggesting a correlation between their activities. PPT-28 was also found to inhibit the growth of influenza A. These four analogs have a 3,4-dihydroxyphenethyl group in common. We also discuss the possibility that 3,4-dihydroxyphenethyl group flexibility may play an important functional role in PA endonuclease inhibition. Another analog harboring a dimethoxyphenethyl group, PPT-62, showed PB2 pathogenicity-determinant domain-binding activity, but did not inhibit the growth of the virus. Our present results indicate the utility of the PA endonuclease assay in the screening of anti-influenza drugs and are therefore useful for future strategies to develop novel anti-influenza A drugs and for mapping the function of the influenza A RNA polymerase subunits. [Copyright &y& Elsevier]

Self-assembly is a powerful technique for the bottom-up construction of discrete, well-defined nanoscale structures. Large multicomponent systems (with more than 50 components) offer mechanistic insights into biological assembly but present daunting synthetic challenges. Here we report the self-assembly of giant M24L48 coordination spheres from 24 palladium ions (M) and 48 curved bridging ligands (L). The structure of this multicomponent system is highly sensitive to the geometry of the bent ligands. Even a slight change in the ligand bend angle critically switches the final structure observed across the entire ensemble of building blocks between M24L48 and M12L24 coordination spheres. The amplification of this small initial difference into an incommensurable difference in the resultant structures is a key mark of emergent behavior. [ABSTRACT FROM AUTHOR]

The anaerobic bacterium Aeromonas sobria is known to cause potentially lethal septic shock. We recently proposed that A. sobria serine protease (ASP) is a sepsis-related factor that induces vascular leakage, reductions in blood pressure via kinin release, and clotting via activation of prothrombin. ASP preferentially cleaves peptide bonds that follow dibasic amino acid residues, as do Kex2 (Saccharomyces cerevisiae serine protease) and furin, which are representative kexin family proteases. Here, we revealed the crystal structure of ASP at 1.65 Å resolution using the multiple isomorphous replacement method with anomalous scattering. Although the overall structure of ASP resembles that of Kex2, it has a unique extra occluding region close to its active site. Moreover, we found that a nicked ASP variant is cleaved within the occluding region. Nicked ASP shows a greater ability to cleave small peptide substrates than the native enzyme. On the other hand, the cleavage pattern for prekallikrein differs from that of ASP, suggesting the occluding region is important for substrate recognition. The extra occluding region of ASP is unique and could serve as a useful target to facilitate development of novel antisepsis drugs. [ABSTRACT FROM AUTHOR]

Diruthenium tetracarbonyl complexes of the type [Ru2(CO)4(μ2-η2-O2CR)2L2] containing a Ru–Ru backbone with four equatorial carbonyl ligands, two carboxylato bridges, and two axial two-electron ligands in a sawhorse-like geometry have been synthesized with porphyrin-derived substituents in the axial ligands [ 1: R is CH3, L is 5-(4-pyridyl)-10,15,20-triphenyl-21,23 H-porphyrin], in the bridging carboxylato ligands [ 2: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23 H-porphyrin, L is PPh3; 3: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23 H-porphyrin, L is 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane], or in both positions [ 4: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23 H-porphyrin, L is 5-(4-pyridyl)-10,15,20-triphenyl-21,23 H-porphyrin]. Compounds 1– 3 were assessed on different types of human cancer cells and normal cells. Their uptake by cells was quantified by fluorescence and checked by fluorescence microscopy. These compounds were taken up by human HeLa cervix and A2780 and Ovcar ovarian carcinoma cells but not by normal cells and other cancer cell lines (A549 pulmonary, Me300 melanoma, PC3 and LnCap prostate, KB head and neck, MDAMB231 and MCF7 breast, or HT29 colon cancer cells). The compounds demonstrated no cytotoxicity in the absence of laser irradiation but exhibited good phototoxicities in HeLa and A2780 cells when exposed to laser light at 652 nm, displaying an LD50 between 1.5 and 6.5 J/cm2 in these two cell lines and more than 15 J/cm2 for the others. Thus, these types of porphyric compound present specificity for cancer cell lines of the female reproductive system and not for normal cells; thus being promising new organometallic photosensitizers. [ABSTRACT FROM AUTHOR]

Abstract: The present study describes the synthesis and characterization of thioarsenicals using electro-spray ionization-MS and time of flight-MS. Separation of thioarsenicals was found to be better by size-exclusion column compared to anion exchange column coupled with HPLC-inductively coupled argon plasma mass spectrometer (ICP MS). Although four thioarsenicals were confirmed as dimethylthioarsinous acid (m/z =138), methylmonothioarsonous acid (m/z =122), dimethyldithioarsinic acid (m/z =170) and methyltrithioarsonic acid (m/z =188), it is noted that HPLC-ICP MS alone were not sufficient for their identification. Also, none of them was stable with time. This is the first report detailing the synthesis and identification of methyltrithioarsonic acid. Both dimethyldithioarsinic acid and dimethylthioarsinous acid were detected in human nail samples while dimethyldithioarsinic acid was found in urine samples. So, the above technique could be applicable to the identification of sulfur-containing biomolecules in the biological samples. [Copyright &y& Elsevier]

Tetrakis(4-hydroxyphenyl)-cavitand 1 and tetra(4-pyridyl)-cavitand 2 self-assemble into a heterodimeric capsule 1·2 via four ArOH⋯pyridyl hydrogen bonds in CDCl3. The 1·2 expresses the orientational isomerism of an encapsulated unsymmetrical guest with high orientational selectivity because the electronic environment of the 1 unit is different from that of the 2 unit. For p-ethoxyiodobenzene and 2-iodo-6-methoxynaphthalene encapsulated in 1·2, the iodo group is specifically oriented to the cavity of the 2 unit. The orientational isomeric selectivity for methyl p-acetoxybenzoate and methyl p-ethoxybenzoate within 1·2 is 1:0.11 and 1:<0.05, respectively, wherein the methyl ester group is preferentially oriented to the cavity of the 2 unit. The delicate balance among electrostatic potential repulsion, CH-π interaction, or CH-halogen (halogen-π) interaction, in 1·2-guest assembly influences the orientational isomeric selectivity of unsymmetrical guests within 1·2. [ABSTRACT FROM AUTHOR]

Abstract: The hydrogen-bonded systems formed between monocarboxylic acid derivatives and the trinuclear arene-ruthenium cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) have been studied in solution by cold-spray ionisation mass spectroscopy (CSI-MS) and in the solid state by single-crystal X-ray structure analysis of the tetrafluoroborate salts. The presence of 1:1 (acid:cluster) adducts in acetone solution has been clearly demonstrated by CSI-MS. Single-crystal X-ray structure analyses of selected acid-cluster complexes show that in every case the hydroxyl of the acid function interacts strongly with the μ3-oxo ligand of cation 1, the O⋯O distance ranging from 2.499(9) to 2.595(11) Å. [Copyright &y& Elsevier]

• α,ω-Diynes bearing a perfluoroalkylene linker were readily prepared from the corresponding dienes in three steps. • Co-catalyzed [2+2+2] cycloaddition of HC≡C(CF 2) 4 C≡CH with alkynes afforded benzene derivatives bearing a perfluorobutan-1,4-diyl group. • HC≡C(CF 2) 6 C≡CH underwent aromatization polymerization by a Rh catalyst to give an insoluble network polymer. α,ω-Diynes bearing a perfluoroalkylene linker HC≡C(CF 2) n C≡H (n = 4,6) were obtained from commercially available α,ω-dienes H 2 C=CH(CF 2) n CH=CH 2 via bromination and dehydrobromination. In the presence of CoCl 2 -Zn-ZnI 2 catalyst, the diyne HC≡C(CF 2) 4 C≡H underwent [2+2+2] cycloaddition reactions with terminal alkynes to afford benzene derivatives fused with an octafluorocyclohexene moiety. In this reaction, trimerization of the diyne was observed as a major side reaction. Rh-catalyzed aromatization polymerization of the diyne HC≡C(CF 2) 6 C≡H afforded an insoluble polymer consisting of a densely cross-linked, aromatic skeleton, which was characterized by solid-state CP-MAS 13C NMR and IR spectroscopy. This insoluble polymer exhibited high thermal stability, and engineering applications of the product polymer are being evaluated. [ABSTRACT FROM AUTHOR]

Anions often quench fluorescence (FL). However, strong ionic hydrogen bonding between fluorescent dyes and anion molecules has the potential to control the electronic state of FL dyes, creating new functions via non-covalent interactions. Here, we propose an approach, utilising ionic hydrogen bonding between urea groups and anions, to control the electronic states of fluorophores and develop an aggregation-induced emission enhancement (AIEE) system. The AIEE ionic hydrogen-bonded complex (IHBC) formed between 1,8-diphenylnaphthalene (p-2Urea), with aryl urea groups at the para-positions on the peri-phenyl rings, and acetate ions exhibits high environmental sensitivities in solution phases, and the FL quantum yield (QY) in ion-pair assemblies of the IHBC and tetrabutylammonium cations is more than five times higher than that of the IHBC in solution. Our versatile and simple approach for the design of AIEE dye facilitates the future development of environment-sensitive probes and solid-state emitting materials., (© 2021. The Author(s).)

A 2 : 4 mixture of tetrakis[4-(4-pyridyl)phenyl]cavitand (1) or tetrakis[4-(4-pyridyl)phenylethynyl]cavitand (2) and Pd(dppp)(OTf) 2 self-assembles into a homocapsule {1 2  ⋅ [Pd(dppp)] 4 } 8+  ⋅ (TfO - ) 8 (C1) or {2 2  ⋅ [Pd(dppp)] 4 } 8+  ⋅ (TfO - ) 8 (C2), respectively, through Pd-Npy coordination bonds. A 1 : 1 : 4 mixture of 1, 2, and Pd(dppp)(OTf) 2 produced a mixture of homocapsules C1, C2, and a heterocapsule {1 ⋅ 2 ⋅ [Pd(dppp)] 4 } 8+  ⋅ (TfO - ) 8 (C3) in a 1 : 1 : 0.98 mole ratio. Selective formation (self-sorting) of homocapsules C1 and C2 or heterocapsule C3 was controlled by guest-induced encapsulation under thermodynamic control. Applications of Pd-Npy coordination capsules with the use of 1 were demonstrated. Capsule C1 serves as a guard nanocontainer for trans-4,4'-diacetoxyazobenzene to protect against the trans-to-cis photoisomerization by encapsulation. A chiral capsule {1 2  ⋅ [Pd((R)-BINAP)] 4 } 8+  ⋅ (TfO - ) 8 (C5) was also constructed. Capsule C5 induces supramolecular chirality with respect to prochiral 2,2'-bis(alkoxycarbonyl)-4,4'-bis(1-propynyl)biphenyls by diastereomeric encapsulation through the asymmetric suppression of rotation around the axis of the prochiral biphenyl moiety., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Synthesis of molecular containers capable of incorporating multiple fullerenes remains challenging. Reported here is that room-temperature mixing of metal ions with W-shaped bispyridine ligands featuring polyaromatic panels results in the quantitative formation of a peanut-shaped M 2 L 4 capsule. The capsule reversibly converts into two molecules of an ML 2 double tube in response to changes in the solvent. Notably, the capsule allows the incorporation of two fullerene molecules into the connected two spherical cavities at room temperature. The close proximity yet non-contact of the encapsulated C 60 molecules, with a separation of 6.4 Å, was revealed by X-ray crystallographic analysis. The resultant, unusual fullerene dimer undergoes sequential reduction within the capsule to generate (C 60 .- ) 2 , C 60 .- ⋅C 60 2- , and (C 60 2- ) 2 species. Furthermore, temperature-controlled stepwise incorporation of two C 60 molecules into the capsule is demonstrated., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A polyaromatic tube with a subnanometer-sized cavity was efficiently prepared on a gram-scale through the stereo-controlled cyclotrimerization of a diphenylanthracene derivative as a key step. The facile exterior alkylation of the polyaromatic framework leads to a moderately fluorescent tube (R=-OC 10 H 21 ; Φ F =20 %) in the solid state. The emission intensity of the solid-state alkyl-substituted tube is remarkably enhanced upon heating (up to 1.6 times, Φ F =31 %) as well as doping with fluorescent dyes (up to 4.2 times, Φ F =83 %) through efficient energy transfer., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

For the development of novel nanospace with unique electrostatic character, we prepared new capsular and tubular nanostructures by the quantitative assembly of metal ions and bent bisacridinium ligands. The capsule and tube have closed spherical and open cylindrical cavities, respectively, with diameters of around 1 nm surrounded by cationic polyaromatic panels. Thanks to the facile synthetic protocol (three steps), another polycationic capsule with an elliptical nanocavity was also prepared by using an elongated ligand. In spite of the absence of pendant hydrophilic groups, the spherical polyaromatic capsule shows sufficient water solubility due to the polycationic shell. Moreover, the highly cationic cavity (12+) can selectively encapsulate anionic organic compounds in water., (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Preparation of molecular nanostructures with polyradical frameworks remains a significant challenge because of the limited synthetic accessibility which is entirely different from that of neutral and ionic ones. Herein we report the quantitative formation of a new M 2 L 4 molecular capsule from metal ions and dihydrophenazine-based ligands. The capsule has a spherical nanocavity (ca. 1 nm in diameter) enclosed by eight redox-active, dihydrophenazine panels. Electrochemical oxidation of the capsule leads to the generation of multiple radical cations on the shell framework. Moreover, a stable tetra(radical cation) capsule can be reversibly obtained by chemical as well as electrochemical oxidation., (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The methyl group is a small substituent, usually showing relatively weak or no interactions with other functional groups and metal ions. Herein, we present the recognition of the number of methyl groups on synthetic and natural aromatic compounds (i.e., benzene and xanthine derivatives, respectively) by the 1 nm-sized polyaromatic cavity of a coordination capsule in water. Detailed competitive encapsulation experiments as well as X-ray crystallographic analysis revealed that multiple guest-host CH3 -polyaromatic interactions in the confined nanospace are key driving forces for the high selectivity., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Trifluoromethylphenyl-substituted phthalimide derivatives favorably form triboluminescence (TL) active noncentrosymmetric crystals. Oligothienyl-, oligophenyl-, and naphthyl-substituted phthalimide derivatives were successfully developed as a series of metal free TL compounds. X-ray crystal structure analyses of bithienyl and naphthyl derivatives revealed noncentrosymmetric layer structures in the same direction. Introduction of suitable electron rich π-units such as thienyl groups enhances their photoluminescence and TL characteristics, and the colors can be also controlled in the visible region. A rigid naphthyl-substituted imide derivative exhibits extremely high TL performance.

The asymmetric unit of the title compound, C19H11N3·C2H2Cl4, consists of one half-mol-ecule of 1,13,14-tri-aza-dibenz[a,j]anthracene (dibenzo[c,h]-1.9,10-anthyridine, dbanth) and one half of 1,1,2,2-tetra-chloro-ethane (TCE), both of which are located on a crystallographic twofold rotation axis. The dihedral angle between the planes of the terminal benzene rings in dbanth is 3.59 (7)° owing to the steric repulsion between the H atoms in the two benzo groups and the H atom in the central pyridine ring of the anthridine skeleton. In the crystal, π-π inter-actions between pyridine rings [centroid-centroid distances = 3.568 (2) and 3.594 (2) Å] link the dbanth mol-ecules to form a one-dimensional columnar structure along the c axis. The dbanth and TCE mol-ecules are connected through weak bifurcated C-H⋯(N,N) hydrogen bonds.

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., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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 Pd(II) ions and four bent bispyridine ligands containing two anthracene panels. Detailed studies of the host capability of the Pd(II)-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 Å(3). 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., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Self-assembly is a powerful technique for the bottom-up construction of discrete, well-defined nanoscale structures. Large multicomponent systems (with more than 50 components) offer mechanistic insights into biological assembly but present daunting synthetic challenges. Here we report the self-assembly of giant M24L48 coordination spheres from 24 palladium ions (M) and 48 curved bridging ligands (L). The structure of this multicomponent system is highly sensitive to the geometry of the bent ligands. Even a slight change in the ligand bend angle critically switches the final structure observed across the entire ensemble of building blocks between M24L48 and M12L24 coordination spheres. The amplification of this small initial difference into an incommensurable difference in the resultant structures is a key mark of emergent behavior.

Complexes of microcystins (MCs) and metal ions were detected with mass spectrometry. To observe the MCs-metals complexes, CryoSpray ionization ion source was developed and it was equipped on a commercial Fourier transform ion resonance mass spectrometer. Mixtures of two MCs and five metals were applied to Fourier transform ion cyclotron resonance mass spectrometry coupled with CryoSpray. The analyses showed complexes of MC-LR-Fe(II), -Zn, -Cu, -Mg, MC-RR-Fe(II), -Zn, -Cu, and -Mg but MC-LR-Fe(III) and MC-RR-Fe(III) were not observed. Present study suggested that MCs may play roles in metal ion uptake and/or accumulation in the algal cells.

[structure: see text] Treatment of a chiral sulfonamide with Et(2)Zn gave quantitatively its Zn complex and then the structure was determined by X-ray crystallographic analysis. Reaction of prochiral N-Boc-2-amino-2-alkyl-1,3-propanediols with Ac(2)O in the presence of 5 mol % of chiral sulfonamide-Zn complex catalyst afforded the corresponding chiral monoacetyl products in 70-92% yields with 70-88% ee values. The proposed mechanism for the catalytic monoacetylation of a prochiral 1,3-propanediol was presented on the basis of CSI-MS analysis.

The selective formation of a homo or hetero cavitand cage composed of two molecules of tetra(4-pyridyl)-cavitand (1), tetrakis(4-cyanophenyl)-cavitand (2), or tetrakis(4-pyridylethynyl)-cavitand (3), and four molecules of Pd(dppp)(OTf)(2) (4) or Pt(dppp)(OTf)(2) (5) has been studied. A 1:1:4 mixture of 1 with more steric restriction, 2 with less coordination ability, and 4 or 5 specifically self-assembled into a hetero cavitand cage 6 or 7, respectively. In contrast, a 1:1:4 mixture of 2, 3, and 4 in CDCl(3) at room temperature assembled into the most labile homo cyanophenyl cavitand cage 8 and the most stable homo pyridylethynyl cavitand cage 9 in a 1:1 ratio. Upon heating at 50 degrees C, the thermodynamic equilibrium was shifted to a 1:1:1 mixture of 8, 9, and a hetero cavitand cage 10. When 1 equiv of 3 was added to 8 at room temperature, 8, 9, and 10 were formed initially in a 1:1:3 ratio and finally shifted to a 1:1:1 ratio. In the Pt-system, upon addition of 1 equiv of 3 to homo cyanophenyl cavitand cage 11 in CDCl(3) at room temperature, the ratio of hetero to homo cavitand cage (13/12) initially attained was 8.7 and remained above 5.6 at room temperature. Upon heating at 50 degrees C, 13 was finally converted to 11 and 12. Thus, the selectivity for the self-assembly of the homo or hetero cavitand cage is controlled by the balance between kinetic and thermodynamic stabilities of cages based on a combination of factors such as coordination ability and steric demand of the cavitands.

The development of a direct catalytic asymmetric aldol-Tishchenko reaction and the nature of its catalyst are described. An aldol-Tishchenko reaction of various propiophenone derivatives with aromatic aldehydes was promoted by [LaLi3(binol)3] (LLB), and reactivity and enantioselectivity were dramatically enhanced by the addition of lithium trifluoromethanesulfonate (LiOTf). First, we observed a dynamic structural change of LLB by the addition of LiOTf using 13C NMR spectroscopy, electronspray ionization mass spectrometry (ESI-MS), and cold-spray ionization mass spectrometry (CSI-MS). X-ray crystallography revealed that the structure of the newly generated self-assembled complex was a binuclear [La2Li4(binaphthoxide)5] complex 6. A reverse structural change of complex 6 to LLB by the addition of one equivalent of Li2(binol) was also confirmed by ESI-MS and experimental results. The drastic concentration effects on the direct catalytic asymmetric aldol-Tishchenko reaction suggested that the addition of LiOTf to LLB generated an active oligomeric catalyst species.