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A series of bis‐(4'‐pyridylethynyl)arenes (arene=benzene, tetrafluorobenzene, and anthracene) were synthesized and their bis‐N‐methylpyridinium compounds were investigated as a class of π‐extended methyl viologens. Their structures were determined by single crystal X‐ray diffraction, and their photophysical and electrochemical properties (cyclic voltammetry), as well as their interactions with DNA/RNA were investigated. The dications showed bathochromic shifts in emission compared to the neutral compounds. The neutral compounds showed very small Stokes shifts, which are a little larger for the dications. All of the compounds showed very short fluorescence lifetimes (<4 ns). The neutral compound with an anthracene core has a quantum yield of almost unity. With stronger acceptors, the analogous bis‐N‐methylpyridinium compound showed a larger two‐photon absorption cross‐section than its neutral precursor. All of the dicationic compounds interact with DNA/RNA; while the compounds with benzene and tetrafluorobenzene cores bind in the grooves, the one with an anthracene core intercalates as a consequence of its large, condensed aromatic linker moiety, and it aggregates within the polynucleotide when in excess over DNA/RNA. Moreover, all cationic compounds showed highly specific CD spectra upon binding to ds‐DNA/RNA, attributed to the rare case of forcing the planar, achiral molecule into a chiral rotamer, and negligible toxicity toward human cell lines at ≤10 μM concentrations. The anthracene‐analogue exhibited intracellular accumulation within lysosomes, preventing its interaction with cellular DNA/RNA. However, cytotoxicity was evident at 1 μM concentration upon exposure to light, due to singlet oxygen generation within cells. These multi‐faceted features, in combination with its two‐photon absorption properties, suggest it to be a promising lead compound for development of novel light‐activated theranostic agents. [ABSTRACT FROM AUTHOR]

Au‐catalyzed hydroamination proceeds well for alkynes but not alkenes. We report gas‐phase binding energies of alkenes and alkynes to a cationic Au center, which indicate that differences in binding are not the origin of the disparate chemical behavior. We further report the synthesis and characterization of 2‐aminoalkylgold complexes, which would be the intermediates in a hypothetical Au‐catalyzed hydroamination of styrene. The reactivity of the well‐characterized and isolable complexes reveals that protonation or alkylation of the 2‐aminoalkylgold complexes results in amine elimination in solution, and in the gas phase, indicating that the failure of Au‐catalyzed alkene hydroamination derives from a non‐competitive protodeauration step. We analyze possible transition states for the protodeauration, and identify an insufficiently strong Au‐proton interaction as the reason that the transition states lie too high in energy to compete. [ABSTRACT FROM AUTHOR]

Alkylating reagents based on thioimidazolium ionic liquids were synthesized and the influence of the anion on the alkylation reaction mechanism explored in detail using both experimental and computational methods. Thioimidazolium cations transfer alkyl substituents to nucleophiles, however the reaction rate was highly dependent on anion identity, demonstrating that the anion is not innocent in the mechanism. Detailed analysis of the computationally‐derived potential energy surfaces associated with possible mechanisms indicated that this dependence arises from a combination of anion induced electronic, steric and coordinating effects, with highly nucleophilic anions catalyzing a 2‐step process while highly non‐nucleophilic, delocalized anions favor a 1‐step reaction. This work also confirms the presence of ion‐pairs and aggregates in solution thus supporting anion‐induced control over the reaction rate and mechanism. These findings provide new insight into an old reaction allowing for better design of cationic alkylators in synthesis, gene expression, polymer science, and protein chemistry applications. [ABSTRACT FROM AUTHOR]

Silica materials attract an increasing amount of interest in (fundamental) research, and find applications in, for example, sensing, catalysis, and drug delivery. As the properties of these (nano)materials not only depend on their chemistry but also their size, shape, and surface area, the controllable synthesis of silica is essential for tailoring the materials to specific applications. Advantageously, bioinspired routes for silica production are environmentally friendly and straightforward since the formation process is spontaneous and proceeds under mild conditions. These strategies mostly employ amine‐bearing phosphorylated (bio)polymers. In this work, we expand this principle to supramolecular polymers based on the water‐soluble cationic cyanine dye Pinacyanol acetate. Upon assembly in water, these dye molecules form large, polyaminated, supramolecular fibers. The surfaces of these fibers can be used as a scaffold for the condensation of silicic acid. Control over the ionic strength, dye concentration, and silicic acid saturation yielded silica fibers with a diameter of 25 nm and a single, 4 nm pore. Unexpectedly, other unusual superstructures, namely, nummulites and spherulites, are also observed depending on the ionic strength and dye concentration. Transmission and scanning electron microscopy (TEM and SEM) showed that these superstructures are formed by aligned silica fibers. Close examination of the dye scaffold prior silicification using small‐angle X‐ray scattering (SAXS), and UV/Vis spectroscopy revealed minor influence of the ionic strength and dye concentration on the morphology of the supramolecular scaffold. Total internal reflection fluorescence (TIRF) during silicification unraveled that if the reaction is kept under static conditions, only silica fibers are obtained. Experiments performed on the dye scaffold and silica superstructures evidenced that the marked structural diversity originates from the arrangement of silica/dye fibers. Under these mild conditions, external force fields can profoundly influence the morphology of the produced silica. [ABSTRACT FROM AUTHOR]

Heterobimetallic cationic sandwich complexes [M(μ‐Cp)M′Cp]+ of group 13 (M=Ga, In) and group 14 (M′=Ge, Sn) elements have been prepared as [WCA]− salts (WCA=Al(ORF)4; ORF=OC(CF3)3). Their molecular structures include free apical gallium or indium atoms. The sandwich complexes were formed in the reactions of [M(HMB)]+[WCA]− (HMB=C6Me6) with the free metallocenes [M′Cp2]. Their structures are related to known stannocene and stannocenium salts; the unprecedented germanium analogues, namely the free germanocenium cation [GeCp]+ and the corresponding triple‐decker complex cation [CpGe(μ‐Cp)GeCp]+, are described herein. By variation of the reaction conditions, these sandwich complexes can be transformed into the group 13/14 mixed cationic coordination polymer [{In(HMB)(μ‐SnCp2)}n][WCA]n. This polymeric chain motif was also successfully replicated by the synthesis of complexes [{Ga/In(HMB)(μ‐FeCp2)}n][WCA]n containing FeCp2 as a bridging ligand. [ABSTRACT FROM AUTHOR]

Solid‐state white light‐emitting electrochemical cells (LECs) show promising advantages of simple solution fabrication processes, low operation voltage, and compatibility with air‐stable cathode metals, which are required for lighting applications. To date, white LECs based on ionic transition metal complexes (iTMCs) have shown higher device efficiencies than white LECs employing other types of materials. However, lower emission efficiencies of red iTMCs limit further improvement in device performance. As an alternative, efficient red CdZnSeS/ZnS core/shell quantum dots were integrated with a blue iTMC to form a hybrid white LEC in this work. By achieving good carrier balance in an appropriate device architecture, a peak external quantum efficiency and power efficiency of 11.2 % and 15.1 lm W−1, respectively, were reached. Such device efficiency is indeed higher than those of the reported white LECs based on host–guest iTMCs. Time‐ and voltage‐dependent electroluminescence (EL) characteristics of the hybrid white LECs were studied by means of the temporal evolution of the emission‐zone position extracted by fitting the simulated and measured EL spectra. The working principle of the hybrid white LECs was clarified, and the high device efficiency makes potential new white‐emitting devices suitable for solid‐state lighting technology possible. [ABSTRACT FROM AUTHOR]

Cobalt‐doped zinc oxide single crystals with the shape of hexagonal platelets were synthesized by thermohydrolysis of zinc acetate, cobalt acetate, and hexamethylenetetramine (HMTA) in mixtures of ethanol and water. The mineralization proceeds by a low‐temperature dissolution–reprecipitation process from the liquid phase by the formation of basic cobalt zinc salts as intermediates. The crystal shape as well as twin formation of the resulting oxide phase can be influenced by careful choice of the solvent mixture and the amount of doping. An understanding of the course of the reaction was achieved by comprehensive employment of analytical techniques (i.e., SEM, XRD, IR) including an in‐depth HRTEM study of precipitates from various reaction stages. In addition, EPR as well as UV/Vis spectroscopic measurements provide information about the insertion of the cobalt dopant into the zincite lattice. The Langmuir–Blodgett (LB) technique is shown to be suitable for depositing coatings of the platelets on glass substrates functionalized with polyelectrolyte multilayers and hence is applied for the formation of monolayers containing domains with ordered tessellation. No major differences are found between deposits on substrates with anionic or cationic surface modification. The adherence to the substrates is sufficient to determine the absolute orientation of the deposited polar single crystals by piezoresponse force microscopy (PFM) and Kelvin probe force microscopy (KPFM) studies. [ABSTRACT FROM AUTHOR]

While numerous hydrogen‐bonded organic frameworks (HOFs) have been reported, typically these cannot be prepared predictably or in a modular fashion. In this work, we report a family of nine diamondoid crystalline porous frameworks assembled via hydrogen bonding between poly‐amidinium and poly‐carboxylate tectons. The frameworks are prepared at room temperature in either water or water/alcohol mixtures. Importantly, both the cationic and anionic components can be varied and additional functionality can be incorporated into the frameworks, which show good stability including to prolonged heating in DMSO or water. [ABSTRACT FROM AUTHOR]

A series of zinc‐based catalysts was evaluated for their efficiency in decomposing formic acid into molecular hydrogen and carbon dioxide in the gas phase using quadrupole ion trap mass spectrometry experiments. The effectiveness of the catalysts in the series [(L)Zn(H)]+, where L=2,2′:6′,2′′‐terpyridine (tpy), 1,10‐phenanthroline (phen) or 2,2′‐bipyrydine (bpy), was found to depend on the ligand used, which turned out to be fundamental in tuning the catalytic properties of the zinc complex. Specifically, [(tpy)Zn(H)]+ displayed the fastest reaction with formic acid proceeding by dehydrogenation to produce the zinc formate complex [(tpy)Zn(O2CH)]+ and H2. The catalysts [(L)Zn(H)]+ are reformed by decarboxylating the zinc formate complexes [(L)Zn(O2CH)]+ by collision‐induced dissociation, which is the only reaction channel for each of the ligands used. The decarboxylation reaction was found to be reversible, since the zinc hydride complexes [(L)Zn(H)]+ react with carbon dioxide yielding the zinc formate complex. This reaction was again substantially faster for L=tpy than L=phen or bpy. The energetics and mechanisms of these processes were modelled using several levels of density functional theory (DFT) calculations. Experimental results are fully supported by the computational predictions. [ABSTRACT FROM AUTHOR]

Abstract: There is an urgent need to identify new, non‐traditional antimicrobials. The discovery of new polymeric antimicrobials is limited by current low‐throughput synthetic tools, which means that limited chemical space has been explored. Herein, we employ photochemical “in‐air” reversible addition–fragmentation chain‐transfer (RAFT) polymerization with microwell plates, using liquid‐handling robots to assemble large libraries of cationic polymers, without the need for degassing or purification steps, facilitating transfer to screening. Several lead polymers were identified including a co‐polymer with propylene glycol side chains with significantly enhanced antimicrobial activity and increased therapeutic window. Mechanistic studies showed that this polymer was bacteriostatic, and surprisingly did not lyse the cell membranes, implying an alternative mode of action. This versatile method using simple robotics will help to develop new biomaterials with emergent properties. [ABSTRACT FROM AUTHOR]

Abstract: The mechanism of H2 activation by recently reported N/Sn Lewis pairs is unravelled using the representative iPr3SnOTf/DABCO combination. Computations provide evidence for weak intermolecular associations between Lewis acid and Lewis base (LA/LB) in which the counteranion to cationic LA fragment plays a critical role. Two frustrated Lewis pairs (FLPs) are observed; an unprecedented counteranion‐mediated noncovalent LA/LB association is characterised along with the usual FLP structure. Both the FLPs are shown to be capable of H2 activation through cooperative electron transfer processes involving the LA/LB centres. Overall, computed results are in good agreement with the experimental findings and account for the observed reactivity. Insights obtained in this study are fundamentally important for the rational design of Sn‐based alternative FLP LAs. The present findings could also provide a general mechanistic framework for H2 activation by FLPs having an ion pair LA component. [ABSTRACT FROM AUTHOR]

Abstract: We provide a proof‐of‐principle that coordination chemistry drives the in situ self‐assembly of an inactive ligand into a multivalent cluster capable of effectively complexing DNA. We show that metal coordination and scavenging can be used to switch the multivalency of the system. Thus, controlled DNA complexation and decomplexation could be achieved. [ABSTRACT FROM AUTHOR]

Abstract: Non‐natural oligonucleotides represent important (bio)chemical tools and potential therapeutic agents. Backbone modifications altering hybridization properties and biostability can provide useful analogues. Here, we employ an artificial nucleosyl amino acid (NAA) motif for the synthesis of oligonucleotides containing a backbone decorated with primary amines. An oligo‐T sequence of this cationic DNA analogue shows significantly increased affinity for complementary DNA. Notably, hybridization with DNA is still governed by Watson–Crick base pairing. However, single base pair mismatches are tolerated and some degree of sequence‐independent interactions between the cationic NAA backbone and fully mismatched DNA are observed. These findings demonstrate that a high density of positive charges directly connected to the oligonucleotide backbone can affect Watson–Crick base pairing. This provides a paradigm for the design of therapeutic oligonucleotides with altered backbone charge patterns. [ABSTRACT FROM AUTHOR]

The synthesis of cyclic alkenyl halides (mainly fluorides, chlorides and bromides) from alkynol or enyne derivatives by an acid-mediated cationic cyclisation reaction is disclosed. This high-yielding, scalable and technically simple method complements and challenges conventional methodologies. This study includes the development of biomimetic cationic cyclisation reactions of polyenyne derivatives to give interesting halogen-containing polycyclic compounds. The application of this reaction in the key step of the synthesis of two terpenes, namely austrodoral and pallescensin A, and the potent odorant 9- epi-Ambrox demonstrates the potential of the reaction for natural product synthesis. [ABSTRACT FROM AUTHOR]

Individual dissimilar blocks were combined to obtain well-defined A nB n and (A-B-A) n types of cationic amphiphilic multiblock copolymers (MBCs) through mild sequential nucleophilic substitution without formation of byproducts. MBCs were synthesized by reacting end-functional polymer blocks of poly(caprolactone) (PCL), poly(ethylene glycol) (PEG), and PCL- b-PEG- b-PCL. For selective degradation, acid- and base-labile ester as well as reducible disulfide groups were introduced as linkers between the blocks. The micellar self-assemblies of these MBCs showed exceptional stability under normal physiological conditions with negligible release of the guest molecules. Selective disassembly under mildly acidic and basic conditions or in the presence of reducing agents caused triggered release of the guest molecules. This strategy is versatile and opens an opportunity to obtain a variety of tailor-made MBCs for selective and triggered release of therapeutics. [ABSTRACT FROM AUTHOR]

Reaction of (TBBP)AlMe ⋅THF with [Cp*2Zr(Me)OH] gave [(TBBP)Al(THF)−O−Zr(Me)Cp*2] (TBBP=3,3',5,5'-tetra- tBu-2,2'-biphenolato). Reaction of [DIPPnacnacAl(Me)−O−Zr(Me)Cp2] with [PhMe2NH]+[B(C6F5)4]− gave a cationic Al/Zr complex that could be structurally characterized as its THF adduct [(DIPPnacnac)Al(Me) −O−Zr(THF)Cp2]+[B(C6F5)4]− (DIPPnacnac=HC[(Me)C=N(2,6- iPr2−C6H3)]2). The first complex polymerizes ethene in the presence of an alkylaluminum scavenger but in the absence of methylalumoxane (MAO). The adduct cation is inactive under these conditions. Theoretical calculations show very high energy barriers (Δ G=40-47 kcal mol−1) for ethene insertion with a bridged AlOZr catalyst. This is due to an unfavorable six-membered-ring transition state, in which the methyl group bridges the metal and ethene with an obtuse metal-Me-C angle that prevents synchronized bond-breaking and making. A more-likely pathway is dissociation of the Al-O-Zr complex into an aluminate and the active polymerization catalyst [Cp*2ZrMe]+. [ABSTRACT FROM AUTHOR]

The donor-stabilized silylene [ iPrNC(N iPr2)N iPr]2Si ( 2) reacts with PhEl−ElPh (El=S, Se) to form the respective cationic five-coordinate bis(guanidinato)silicon(IV) complexes {[ iPrNC(N iPr2)N iPr]2SiSPh}+PhS− ( 4) and {[ iPrNC (N iPr2)N iPr]2SiSePh}+PhSe− ( 5). Compounds 4 and 5 were characterized by crystal structure analyses and NMR spectroscopic studies in the solid state. [ABSTRACT FROM AUTHOR]

This paper describes the formation of new platinacyclic complexes derived from the phosphine ligands P iPr2Xyl, PMeXyl2, and PMe2Ar [ABSTRACT FROM AUTHOR]

Eight [Ir(bpy)Cp*Cl]+-type complexes (bpy= bipyridine, Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) containing differently substituted bipyridine ligands were synthesized and characterized. Cyclic voltammetry (CV) of the complexes in Ar-saturated acetonitrile solutions showed that the redox behavior of the complexes could be fine tuned by the electronic properties of the substituted bipyridine ligands. Further CV in CO2-saturated MeCN/H2O (9:1, v/v) solutions showed catalytic currents for CO2 reduction. In controlled potential electrolysis experiments (MeCN/MeOH (1:1, v/v), Eapp=−1.80 V vs Ag/AgCl), all of the complexes showed moderate activity in the electrocatalytic reduction of CO2 with good stability over at least 15 hours. This electrocatalytic process was selective toward formic acid, with only traces of dihydrogen or carbon monoxide and occasionally formaldehyde as byproducts. However, the turnover frequencies and current efficiencies were quite low. No direct correlation between the redox potentials of the complexes and their catalytic activity was observed. [ABSTRACT FROM AUTHOR]

[WMe6] ( 1) supported on the surface of SiO2-Al2O3(500) ( 2) has been extensively characterized by solid-state NMR spectroscopy, elemental analysis, and gas quantification, which clearly reveal the formation of a mixture of monopodal and bipodal species with the migration of methyl from W to Al. The supported species SiO2-Al2O3(500) ( 2) transformed at 120 °C into two types of carbynic centers, one of which is cationic and the other neutral. These species are very efficient for the metathesis of n-decane. Comparison with already-synthesized neutral bipodal tungsten indicates that the high increase in activity is due to the cationic character of the grafted tungsten. [ABSTRACT FROM AUTHOR]

The design of smart nonviral vectors for gene delivery is of prime importance for the successful implementation of gene therapies. In particular, degradable analogues of macromolecules represent promising targets as they would combine the multivalent presentation of multiple binding units that is necessary for achieving effective complexation of therapeutic oligonucleotides with the controlled degradation of the vector that would in turn trigger drug release. Toward this end, we have designed and synthesized hybrid polyacylhydrazone-based dynamic materials that combine bis-functionalized cationic monomers with ethylene oxide containing monomers. Polymer formation was characterized by 1H and DOSY NMR spectroscopy and was found to take place at high concentration, whereas macrocycles were predominantly formed at low concentration. HPLC monitoring of solutions of these materials in aqueous buffers at pH values ranging from 5.0 to 7.0 revealed their acid-catalyzed degradation. An ethidium bromide displacement assay and gel electrophoresis clearly demonstrated that, despite being dynamic, these materials are capable of effectively complexing dsDNA in aqueous buffer and biological serum at N/P ratios comparable to polyethyleneimine polymers. The self-assembly of dynamic covalent polymers through the incorporation of a reversible covalent bond within their main chain is therefore a promising strategy for generating degradable materials that are capable of establishing multivalent interactions and effectively complexing dsDNA in biological media. [ABSTRACT FROM AUTHOR]

A cationic ruthenium(II)-complex was utilized in the efficient synthesis of phthalimide derivatives by C-H activation with synthetically useful amides. The reaction proceeded through a mechanistically unique insertion of a cycloruthenated species into a C-Het multiple bond of isocyanate. The novel method also proved applicable for the synthesis of heteroaromatic unsymmetric diamides as well as a potent COX-2 enzyme inhibitor. [ABSTRACT FROM AUTHOR]

An unexpected cationic bis-N-heterocyclic carbene (NHC) benzylidene ether based ruthenium complex ( 2 a) was prepared through the double incorporation of an unsymmetrical unsaturated N-heterocyclic carbene (U2-NHC) ligand that bore an N-substituted cyclododecyl side chain. The isolation and full characterization (including X-ray diffraction studies) of key synthetic intermediates along with theoretical calculations allowed us to understand the mechanism of the overall cationization process. Finally, the newly developed complex 2 a displayed interesting latent behavior during ring-closing metathesis, which could be 'switched on' under acidic conditions. [ABSTRACT FROM AUTHOR]

The photoionization and dissociative photoionization of 1,4-di- tert-butyl-1,4-azaborinine by means of synchrotron radiation and threshold photoelectron photoion coincidence spectroscopy is reported. The ionization energy of the compound was determined to be 7.89 eV. Several low-lying electronically excited states in the cation were identified. The various pathways for dissociative photoionization were modeled by statistical theory, and appearance energies AE0K were obtained. The loss of isobutene in a retro-hydroboration reaction is the dominant pathway, which proceeds with a reverse barrier. Pyrolysis of the parent compound in a chemical reactor leads to the generation of several yet unobserved boron compounds. The ionization energies of the C4H6BN isomers 1,2- and 1,4-dihydro-1,4-azaborinine and the C3H6BN isomer 1,2-dihydro-1,3-azaborole were determined from threshold photoelectron spectra. [ABSTRACT FROM AUTHOR]

The development and mechanistic investigation of a highly stereoselective methodology for preparing α-linked-urea neo-glycoconjugates and pseudo-oligosaccharides is described. This two-step procedure begins with the selective nickel-catalyzed conversion of glycosyl trichloroacetimidates to the corresponding α-trichloroacetamides. The α-selective nature of the conversion is controlled with a cationic nickel(II) catalyst, [Ni(dppe)(OTf)2] (dppe=1,2-bis(diphenylphosphino)ethane, OTf=triflate). Mechanistic studies have identified the coordination of the nickel catalyst with the equatorial C2-ether functionality of the α-glycosyl trichloroacetimidate to be paramount for achieving an α-stereoselective transformation. A cross-over experiment has indicated that the reaction does not proceed in an exclusively intramolecular fashion. The second step in this sequence is the direct conversion of α-glycosyl trichloroacetamide products into the corresponding α-urea glycosides by reacting them with a wide variety of amine nucleophiles in presence of cesium carbonate. Only α-urea-product formation is observed, as the reaction proceeds with complete retention of stereochemical integrity at the anomeric CN bond. [ABSTRACT FROM AUTHOR]

We found that phenethylcarbamates that bear ortho-salicylate as an ether group (carbamoyl salicylates) dramatically accelerate OC bond dissociation in strong acid to facilitate generation of isocyanate cation (N-protonated isocyanates), which undergo subsequent intramolecular aromatic electrophilic cyclization to give dihydroisoquinolones. To generate isocyanate cations from carbamates in acidic media as electrophiles for aromatic substitution, protonation at the ether oxygen, the least basic heteroatom, is essential to promote CO bond cleavage. However, the carbonyl oxygen of carbamates, the most basic site, is protonated exclusively in strong acids. We found that the protonation site can be shifted to an alternative basic atom by linking methyl salicylate to the ether oxygen of carbamate. The methyl ester oxygen ortho to the phenolic (ether) oxygen of salicylate is as basic as the carbamate carbonyl oxygen, and we found that monoprotonation at the methyl ester oxygen in strong acid resulted in the formation of an intramolecular cationic hydrogen bond (>CO+H⋅⋅⋅O<) with the phenolic ether oxygen. This facilitates OC bond dissociation of phenethylcarbamates, thereby promoting isocyanate cation formation. In contrast, superacid-mediated diprotonation at the methyl ester oxygen of the salicylate and the carbonyl oxygen of the carbamate afforded a rather stable dication, which did not readily undergo CO bond dissociation. This is an unprecedented and unknown case in which the monocation has greater reactivity than the dication. [ABSTRACT FROM AUTHOR]

The synthesis of a series of new lipid-inspired ionic liquids through thiol-ene 'click' reaction with a single-step process. This synthesis offers considerable promise as an efficient and orthogonal method to construct structurally diverse imidazolium-type ionic liquids with linear and branched cationic tails, as well as versatility in the placement of the sulfur heteroatom. Profound solvent effect in this ene reaction regioselectivity has been observed. [ABSTRACT FROM AUTHOR]

The ability of cyclodextrin-based polycationic cluster to undergo reversible DNA condensation and release in a physiologically useful pH window has been finely tuned by the installation of a capping xylylene moiety at the secondary face of the cyclooligosaccharide. This strategy can be exploited advantageously in the design of self-assembling nonviral gene-delivery systems from molecular entities. [ABSTRACT FROM AUTHOR]

A novel turn-on fluorogenic chiral sensory system has been developed using a protonated riboflavin and riboflavin-derived cationic polymer as a fluorophore precursor and a specific amine receptor, respectively, which enables the solid-state chemo- and enantioselective fluorogenic visual detection of primary and secondary amine vapors. [ABSTRACT FROM AUTHOR]

Supramolecular assembly: Spherical and stable hybrid assemblies based on a cationic polymer with spermine side chains and an anionic Gd3+‐containing polyoxometalate cluster (GdW) are prepared by electrostatic interaction (see figure). The T1‐weighted MRI performance of GdW is enhanced about three times in the assemblies; meanwhile, the assemblies show good biocompatibility, which enables them to be promising candidates for MRI contrast agents. [ABSTRACT FROM AUTHOR]

The transfer-hydrogenative cyclization of 1,6-diynes with Hantzsch 1,4-dihydropyridine as a H2 surrogate was performed in the presence of a cationic ruthenium catalyst of the type [Cp′Ru(MeCN)3PF6]. Exocyclic 1,3-dienes or their 1,4-hydrogenation products, cycloalkenes, were selectively obtained, depending on the substrate structure and the reaction conditions. [ABSTRACT FROM AUTHOR]

Highlights from the article: The authors have been alerted to an error in the reported electrochemical potential values. In fact, the Fc/Fc SP + sp redox couple exhibits an oxidation potential value of 0.42 V vs. .