ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTNew Cucurbituril Homologues: Syntheses, Isolation, Characterization, and X-ray Crystal Structures of Cucurbit[n]uril (n = 5, 7, 8)Jaheon Kim, In-Sun Jung, Soo-Young Eunsung Lee, Jin-Koo Kang, Shigeru Sakamoto, Kentaro Yamaguchi, Kimoon KimView Author Information National Creative Research Initiative Center for Smart Supramolecules Department Chemistry Pohang University Science Technology San 31 Hyojadong, 790-784, Republic Korea Chemical...

Two different molecules are selectively included in cucurbit[8]uril to form a stable 1:1:1 ternary complex, which has been characterized by X-ray crystallography (see picture). The inclusion of hetero-guest pair (a pyridinium derivative (blue) and 2,6-dihydroxynaphthalene (magenta)) the molecular host is driven stabilized charge-transfer interaction between electron-rich electron-deficient guests.

The unnatural isotope fluorine-18 ((18)F) is used as a positron emitter in molecular imaging. Currently, many potentially useful (18)F-labeled probe molecules are inaccessible for imaging because no fluorination chemistry available to make them. 110-minute half-life of (18)F requires rapid syntheses which [(18)F]fluoride the preferred source fluorine its practical access and suitable enrichment. However, conventional has been limited nucleophilic reactions. We report development...

A one-step oxidative fluorination for carbon-fluorine bond formation from well-defined nickel complexes with oxidant and aqueous fluoride is presented, which enables a straightforward practical (18)F late-stage of complex small molecules potential PET imaging.

Separation of acetylene from carbon dioxide and ethylene is challenging in view their similar sizes physical properties. Metal-organic frameworks (MOFs) general are strong candidates for these separations owing to the presence functional pore surfaces that can selectively capture a specific target molecule. Here, we report novel 3D microporous cationic framework named JCM-1. This structure possesses imidazolium groups on pyrazolate as metal binding group, which well known form...

A new approach to the synthesis of hierarchical micro- and mesoporous MOFs from microporous involves a simple hydrolytic post-synthetic procedure. As proof concept, MOF, POST-66(Y), was synthesized its transformation into MOF by water treatment studied. This method produced mesopores in range 3 20 nm while maintaining original structure, at least part. The degree mesoporosity can be controlled adjusting time temperature hydrolysis. resulting porous POST-66(Y)-wt, utilized encapsulate...

The porphyrin boxes (PB-1 and PB-2), which are rationally designed porous organic cages with a large cavity using well-defined rigid 3-connected triangular 4-connected square shaped building units reported. PB-1 has as 1.95 nm in diameter shows high chemical stability broad pH range (4.8 to 13) aqueous media. crystalline nature well structure of the shape-persistent cage crystals were intact even after complete removal guest molecules, leading one highest surface areas (1370 m(2) g(-1))...

Cucurbituril is used as the molecular "bead" for synthesis of first three-dimensional polyrotaxane network, which shows an inclined α-polonium topology. The novel solid-state interlocked structure made up binulcear Tb3+ centers and pseudorotaxane units containing cucurbituril "beads" threaded on a "string" with 3-phenylcarboxylate terminals (shown schematically). Supporting information this article available WWW under http://www.wiley-vch.de/contents/jc_2002/2000/z14929_s.pdf or from author....

A chemo- and regioselective α-hydroxylation reaction of carbonyl compounds with molecular oxygen as oxidant is reported. The hydroxylation catalyzed by a dinuclear Pd(II) complex, which functions an transfer catalyst, reminiscent oxygenase. development this oxidation was inspired discovery mechanism evaluation previously unknown Pd(III)-Pd(III) complexes.

A seven-membered molecular necklace composed of six copper ions and pseudorotaxane units behaves as a secondary building block in the formation two-dimensional polyrotaxane network with large voids (see picture). This novel metal–organic framework allows size-selective anion exchange well coordinated ligands. Thus new synthetic strategy has been identified for modular porous solids which utilizes large, rigid, interlocked supermolecules primary or blocks. Supporting information this article...

A silver-mediated cross-coupling of trifluoromethoxide with aryl stannanes and arylboronic acids to give trifluoromethyl ethers is reported. This the first report a transition-metal-mediated Caryl–OCF3 bond formation.

Oxidation of binuclear Pd(II) complexes with PhICl2 or PhI(OAc)2 has previously been shown to afford Pd(III) featuring a Pd–Pd bond. In contrast, oxidation electrophilic trifluoromethylating ("CF3+") reagents reported mononuclear Pd(IV) complexes. Herein, we report experimental and computational studies the complex "CF3+" reagents. These suggest that is generated by an oxidation–fragmentation sequence proceeding via fragmentation initially formed, formally Pd(III), intermediate. The...

To promote the oxygen reduction reaction of metal-free catalysts, introduction porous structure is considered as a desirable approach because can enhance mass transport and host many catalytic active sites. However, most previous studies reported only half-cell characterization; therefore, on membrane electrode assembly (MEA) are still insufficient. Furthermore, effect doping-site position in has not been investigated. Here, we report synthesis highly catalysts MEAs by controlling pore size...

Ring expansion metathesis polymerization (REMP) has emerged as a potent strategy for obtaining cyclic polymers over the past two decades. The scope of monomers, however, remains limited due to poor functional group tolerance and stability catalyst, necessitating rational catalyst design address this constraint. Here, we present ruthenium complexes featuring tethered (alkyl)(amino)carbene ligands REMP, aiming deepen our understanding structure–property relationship in newly designed...

Efficient separation of hydrogen isotopes, especially deuterium (D2), is pivotal for advancing industries such as nuclear fusion, semiconductor processing, and metabolic imaging. Current technologies, including cryogenic distillation Girdler sulfide processes, suffer from significant limitations in selectivity cost‐effectiveness. Herein, we introduce a novel approach utilizing an imidazolium‐based Metal‐Organic Framework (MOF), JCM‐1, designed to enhance D2/H2 through temperature‐dependent...

Reminiscent of Russian Matrioshka dolls, tetraazamacrocycles (1,4,7,10-tetraazacyclododecane (cyclen) and 1 , 4 8 11 - tetraazacyclotetradecane (cyclam)) their transition metal complexes are encapsulated in the cavity cucurbit[8]uril (CB[8]). The X-ray crystal structure [Cu(cyclen)] CB[8] complex (see picture; copper: green, oxygen: red, nitrogen: blue, carbon: gray) reveals a five-coordinate CuII center square-pyramidal environment with water molecule bound to axial position.

This paper reports a synthetic strategy to construct one- and two-dimensional (1D 2D) polyrotaxanes, in which number of rings are threaded onto coordination polymer, by the combination self-assembly chemistry. Our approach polyrotaxanes with high structural regularity involves threading cucurbituril (CB) "bead" short "string" form stable pseudorotaxane, followed linking pseudorotaxanes metal ions as "linkers" organize into 1D or 2D polyrotaxane. A 4- 3-pyridylmethyl group is attached each...

New chemistry methods for the synthesis of radiolabeled small molecules have potential to impact clinical positron emission tomography (PET) imaging, if they can be successfully translated. However, progression modern reactions from stage synthetic development preparation radiotracer doses ready use in human PET imaging is challenging and rare. Here we describe process successful translation a palladium-mediated fluorination reaction non-human primate (NHP) baboon imaging-an important...

Abstract Separation of acetylene from carbon dioxide and ethylene is challenging in view their similar sizes physical properties. Metal–organic frameworks (MOFs) general are strong candidates for these separations owing to the presence functional pore surfaces that can selectively capture a specific target molecule. Here, we report novel 3D microporous cationic framework named JCM‐1 . This structure possesses imidazolium groups on pyrazolate as metal binding group, which well known form...

Stable organic radicals have been of great academic interest not only in the context fundamental understanding reactive intermediates but also because their numerous applications as functional materials. Apart from early examples triphenylmethyl and TEMPO derivatives, reports on air- water-stable are scarce, development remains a challenge. Herein, we present design synthesis novel radical based 1,2-dicarbonyl scaffold supported by N-heterocyclic carbenes (NHCs). The presented cations...