Synthesis of Quinoline-Indole Hybrids through Cu(II)-Catalyzed Amination and Annulation between -Oxides and -Alkynylanilines.

The synthesis of (iso)quinoline-indole hybrids by reacting (iso)quinoline -oxides with -alkynylanilines in the presence of a combination of copper(II) catalyst and a bidentate 2,2'-bipyridine ligand is described. The utility of this method was demonstrated through site-selective functionalization of the synthesized products. A plausible reaction pathway for site-selective amination followed by annulative indole formation was elucidated by a series of mechanistic investigations.

Reusable Wrinkled Nanoporous Silver Film Fabricated by Plasma Treatment for Surface-Enhanced Raman Scattering Applications.

A nanoporous silver film (npAgF), a promising structure for surface-enhanced Raman spectroscopy (SERS), can be fabricated by using successive O and Ar plasma treatments on a planar silver film. The common dealloying method for producing an npAgF involves annealing at high temperatures to produce an alloy film, as well as harsh etching using corrosive chemicals. By contrast, the plasma-based method can be applied directly to various functional substrates to produce more sophisticated npAgF structures.

KOBu-promoted C3-homocoupling of quinoxalinones through single electron transfer from an sp carbanion intermediate.

The C3-selective homodimerization of quinoxalinones is described. A C3-sp carbanion species generated through deprotonation of quinoxalinone using potassium -butoxide (KOBu) transfers an electron (single electron transfer mechanism) to a second quinoxalinone, affording a radical-anion intermediate. The radical scavenging and electron paramagnetic resonance (EPR) experiments support the plausible radical reaction pathway.

Synthesis of π-Extended Heterocycles via Rh(III)-Catalyzed Oxidative Annulation of 5-Aryl Pyrazinones with Alkynes.

The Rh(III)-catalyzed C-H functionalization and subsequent oxidative annulation between 5-aryl pyrazinones and internal alkynes are reported. This protocol provides facile access to a wide range of pyrazinone-linked naphthalenes via the C(sp)-H alkenylation and subsequent annulation. This transformation is characterized by mild conditions, simplicity, and excellent functional group compatibility.

Synthesis of (2)-Indazoles and Dihydrocinnolinones through Annulation of Azobenzenes with Vinylene Carbonate under Rh(III) Catalysis.

The Rh(III)-catalyzed C-H functionalization and subsequent intramolecular cyclization between azobenzenes and vinylene carbonate is described herein. Depending on the electronic property of azobenzenes, this transformation results in the formation of (2)-indazoles or dihydrocinnolin-4-ones through the generation of -alkylated azo-intermediates followed by decarboxylation. Surprisingly, vinylene carbonate acts as an acetaldehyde or acetyl surrogate to enable the [4 + 1] or [4 + 2] annulation reaction.

Correction: Changes in macrocyclic aromaticity and formation of a charge-separated state by complexation of expanded porphyrin and C.

Correction for 'Changes in macrocyclic aromaticity and formation of a charge-separated state by complexation of expanded porphyrin and C' by Won-Young Cha et al., Chem. Commun.

Ratiometric Turn-On Fluorophore Displacement Ensembles for Nitroaromatic Explosives Detection.

There is a recognized need in the area of explosives detection for fluorescence-based sensing systems that are capable of not only producing a turn-on response but also generating a distinctive spectral signature for a given analyte. Here, we report several supramolecular ensembles displaying efficient fluorophore displacement that give rise to an increase in fluorescence intensity upon exposure to various nitroaromatic compounds. The synthetic supramolecular constructs in question consist of a tetrathiafulvalene (TTF)-based pyrrolic macrocycle, benzo-TTF-calix[4]pyrrole (Bz-TTF-C4P), and fluorescent dyes, monomeric or dimeric naphthalenediimide (NDI) and perylenediimide (PDI) derivatives, as well as chloride or hexafluorophosphate (PF) salts of rhodamine 6G (Rh-6G).

Changes in macrocyclic aromaticity and formation of a charge-separated state by complexation of expanded porphyrin and C60.

Significant changes of macrocyclic aromaticity in expanded porphyrins through C60 complexation were studied by 1H NMR spectroscopy and nucleus-independent chemical shift calculations. This work is a detailed research study of how the formation of a complex of dual aromatic expanded porphyrin with fullerene affects the electron densities in the main conjugation pathways and meso-substituents. Furthermore, we found that the formation of the photoinduced charge-separated state and the triplet excited-state populations of the bowl-shaped and rigid expanded porphyrin can be controlled by a simple complexation with C60.

Expression of CPNE7 during mouse dentinogenesis.

Interactions between the ectodermal and mesenchymal tissues are the basis of the central mechanism regulating tooth development. Based on this epithelial-mesenchymal interaction (EMI), we demonstrated that copine-7 (CPNE7) is secreted by preameloblasts and regulates the differentiation of mesenchymal cells of dental or non-dental origin into odontoblasts. However, the precise expression patterns of CPNE7 in the stages of tooth development have not yet been elucidated.

Tetrathiafulvalene (TTF)-Annulated Calix[4]pyrroles: Chemically Switchable Systems with Encodable Allosteric Recognition and Logic Gate Functions.

Molecular and supramolecular systems capable of switching between two or more states as the result of an applied chemical stimulus are attracting ever-increasing attention. They have seen wide application in the development of functional materials including, but not limited to, molecular and supramolecular switches, chemosensors, electronics, optoelectronics, and logic gates. A wide range of chemical stimuli have been used to control the switching within bi- and multiple state systems made up from either singular molecular entities or supramolecular ensembles.

Synthesis of TMPA Derivatives through Sequential Ir(III)-Catalyzed C-H Alkylation and Their Antidiabetic Evaluation.

The synthesis and antidiabetic evaluation of ethyl 2-[2,3,4-trimethoxy-6-(1-octanoyl)phenyl]acetate (TMPA) and its structural analogs are described. The construction of TMPA derivatives has been successfully achieved in only two steps, which involve the iridium(III)-catalyzed α-alkylation of acetophenones with alcohols and the ketone-directed iridium(III)- or rhodium(III)-catalyzed redox-neutral C-H alkylation of α-alkylated acetophenones using Meldrum's diazo compounds. This synthetic protocol efficiently provides a range of TMPA derivatives with site selectivity and functional group compatibility.

Non-destructive monitoring of apple ripeness using an aldehyde sensitive colorimetric sensor.

We developed an on-packaging colorimetric sensor label that can detect the aldehyde emission of apples based on Methyl Red. The sensor label was constructed using printable inks on paper medium and relied on the change in basicity caused by the nucleophilic addition reaction between aldehyde and hydroxide via the Cannizzaro reaction. The sensor can be used to detect aldehyde in solution and vapor.

Dual Role of Anthranils as Amination and Transient Directing Group Sources: Synthesis of 2-Acyl Acridines.

The transient directing group promoted C(sp)-H functionalization of benzaldehydes with anthranils by a cationic rhodium(III) catalyst is described. Notably, anthranils have been used as both transient directing groups and amination sources to afford 2-acyl acridines through direct C-H amination followed by acid-mediated cyclization. A range of substrate scopes and functional group tolerance were observed.

Disparate Downstream Reactions Mediated by an Ionically Controlled Supramolecular Tristate Switch.

The use of chemical messengers to control multiple and often disparate downstream events is a hallmark of biological signaling. Here, we report a synthetic supramolecular construct that gives rise to bifurcated downstream events mediated by different stimulus-induced chemical messengers. The system in question consists of a supramolecular redox-ensemble made up of a tetrathiafulvalene (TTF)-based macrocycle, benzo-TTF-calix[4]pyrrole, and an electron deficient partner, 7,7,8,8-tetracyanoquinodimethane (TCNQ).

Electrochemical amphotericity and NIR absorption induced via the step-wise protonation of fused quinoxaline-tetrathiafulvalene-pyrroles.

We describe an effective approach to producing electrochemical amphoteric character and tuning optical properties. Reversible step-wise protonation of quinoxaline annulated TTF-pyrrole derivatives promotes intramolecular electron-transfer and leads to formation of stable, fully charge-separated diradical states. This allows for the creation of low bandgap systems and NIR optical properties.

Control over multiple molecular states with directional changes driven by molecular recognition.

Recently, ligand-metal coordination, stimuli-responsive covalent bonds, and mechanically interlinked molecular constructs have been used to create systems with a large number of accessible structural states. However, accessing a multiplicity of states in sequence from more than one direction and doing so without the need for external energetic inputs remain as unmet challenges, as does the use of relatively weak noncovalent interactions to stabilize the underlying forms. Here we report a system based on a bispyridine-substituted calix[4]pyrrole that allows access to six different discrete states with directional control via the combined use of metal-based self-assembly and molecular recognition.

Bicyclic Baird-type aromaticity.

Classic formulations of aromaticity have long been associated with topologically planar conjugated macrocyclic systems. The theoretical possibility of so-called bicycloaromaticity was noted early on. However, it has yet to be demonstrated by experiment in a simple synthetic organic molecule.

Tetrathiafulvalene- (TTF-) Derived Oligopyrrolic Macrocycles.

After the epochal discovery of the "organic metal", namely, tetrathiafulvalene (TTF)-7,7,8,8-tetracyano-p-quinodimethane (TCNQ) dyad in 1973, scientists have made efforts to derivatize TTF for constructing various supramolecular architectures to control the charge-transfer processes by adjusting the donor-acceptor strength of the dyads for numerous applications. The interesting inherent electronic donor properties of TTFs control the overall electrochemical properties of the supramolecular structures, leading to the construction of highly efficient optoelectronic materials, photovoltaic solar cells, organic field-effect transistors, and optical sensors. Modified TTF structures thus constitute promising candidates for the development of so-called "functional materials" that could see use in modern technological applications.

Probing and evaluating anion-π interaction in meso-dinitrophenyl functionalized calix[4]pyrrole isomers.

We investigate anion-π binding modes in a cis-isomer of 3,5-dinitrophenyl-substituted calix[4]pyrrole with various anions via X-ray crystallographic analyses and compare its binding affinities with those of the corresponding trans-isomer. Sandwich-type anion-π interactions prove to not only enhancing anion binding abilities but also altering the anion-binding selectivity of the calix[4]pyrrole framework.

Mid-IR spectroscopy of Fe:ZnSe quantum dots.

We report spectroscopic characterization of Fe:ZnSe quantum dots (for 2% of Zn/Fe molar ratio) fabricated by microemulsion hydrothermal synthesis. Mid-IR photoluminescence of the E↔T transition of Fe ions over 3.5-4.

Numerical analysis of thermal decomposition for RDX, TNT, and Composition B.

Demilitarization of waste explosives on a commercial scale has become an important issue in many countries, and this has created a need for research in this area. TNT, RDX and Composition B have been used as military explosives, and they are very sensitive to thermal shock. For the safe waste treatment of these high-energy and highly sensitive explosives, the most plausible candidate suggested has been thermal decomposition in a rotary kiln.

Redox- and pH-Responsive Orthogonal Supramolecular Self-Assembly: An Ensemble Displaying Molecular Switching Characteristics.

Two heteroditopic monomers, namely a thiopropyl-functionalized tetrathiafulvalene-annulated calix[4]pyrrole (SPr-TTF-C[4]P 1) and phenyl C61 butyric acid (PCBA 2), have been used to assemble a chemically and electrochemically responsive supramolecular ensemble. Addition of an organic base initiates self-assembly of the monomers via a molecular switching event. This results in the formation of materials that may be disaggregated via the addition of an organic acid or electrolysis.

Light-Emitting Diodes with Hierarchical and Multifunctional Surface Structures for High Light Extraction and an Antifouling Effect.

Bioinspired hierarchical structures on the surface of vertical light-emitting diodes (VLEDs) are demonstrated by combining a self-assembled dip-coating process and nanopatterning transfer method using thermal release tape. This versatile surface structure can efficiently reduce the total internal reflection and add functions, such as superhydrophobicity and high oleophobicity, to achieve an antifouling effect for VLEDs.

Partial dark-field microscopy for investigating domain structures of double-layer microsphere film.

A lateral dislocation in a double-layer microsphere film is very difficult to identify because the constituent domains have the same two-dimensional crystalline orientation. Orientation-sensitive optical techniques cannot resolve this issue. Here, we demonstrate that partial dark-field (pDF) optical microscopy can be very effective in identifying this type of domain boundary and dislocation of a close-packed microsphere double-layer.