Copper-catalyzed dimerization fragmentation cyclization reactions of (E)-1-en-4-yn-3-ols as a versatile approach for the synthesis of multisubstituted 1H-cyclopenta[b]naphthalenes

An intermolecular condensation reaction of 1,3,5-triarylenynols catalyzed by copper is developed. This reaction is a straightforward method for the synthesis of highly conjugated 1H-cyclopenta[b]naphthalene. Fluorescent properties have been determined for some of the products.     

Molecular tectonics: design of enantiomerically pure helical tubular crystals with controlled channel size and orientation

The combination of four enantiomerically pure organic tectons composed of a rigid chiral backbone bearing two terminal pyridyl coordinating sites with ZnSiF(6) behaving as an infinite pillar leads to the formation of tubular 2-D enantiomerically pure helical channels with controlled size and orientation.     

A Triphenylphosphonium Functionalized AIE Conjugated Macrocyclic Tetramaleimide for Mitochondrial-targeting Bioimaging

Development of subcellular organelle-targeted bioimaging probes is of great importance in the field of early detection of diseases and exploring the behaviors of subcellular organelles. Herein, we present a triphenylphosphonium functionalized conjugated macrocyclic tetramaleimide (TPP-CMT) as a mitochondrial-targeting bioimaging probe. The core of TPP-CMT is obtained by connecting two pyrenes and two benzenes through four maleimides. This unique structure endows TPP-CMT with exceptional far red/near-infrared aggregation-induced emission (FR/NIR-AIE) characteristics. TPP-CMT is an excellent fluorescent emitter in most solvents and even in solid states. The quantum yield of TPP-CMT was higher than 27% when dissolved in common middle-polarity organic solvent and this value remained at 28.2% in its solid state. The introduction of four triphenylphosphonium on maleimide positions endows TPP-CMT with mitochondrial-targeting ability. Thanks to the FR/NIR-AIE characteristics and the mitochondrial-targeting ability, this well-designed fluorescent probe was successfully employed for mitochondrial targeting bioimaging of HeLa and HepG2 cells.      

Synthesis, characterization, spectroscopic, and electrochemiluminescence properties of a solvatochromic azacrown-containing cyanoruthenate(II): potential applications in separation and indirect photometric detection of cations and amino acids in HPLC

A new anionic ruthenium(II) complex, (Et4N)[Ru(tpyA18C6)(CN)3] (tpyA18C6=N-[4'-(2,2':6',2'-terpyridyl)]-1,4,7,10,13-pentaoxa-16-azacyclohexadodecane), has been synthesized and characterized. The complex was found to show pronounced solvatochromic behavior and, when dissolved in solution, changed its color from purple to yellow when the solvent system was varied from pure acetonitrile to pure water. Its absorption and emission energies in various solvents showed a linear dependence of the Gutman's acceptor number. The characteristic photoluminescence and electrochemiluminescence (ECL) of the complex were also found to be progressively quenched as the proportion of water in a water/acetonitrile mixture increased. Large changes in the chemical shifts of the 1H NMR and 13C NMR signals of [Ru(tpyA18C6)(CN)3]- in different solvents were observed. The complex has also been demonstrated to serve as a mobile-phase additive in high-performance liquid chromatography for separation of metal cations and amino acids. Comparison studies with the crown-free analogue, (Et4N)[Ru(tpy)(CN)3] (tpy = 2,2':6',2'-terpyridine), showed that other than the ion-pair effect, the allosteric host-guest interaction provided by the presence of the pendant crown was essential to the separation performance of the complex. Indirect detection of nonabsorbing analytes has been achieved by monitoring the absorbance changes of the eluent at the metal-to-ligand charge-transfer (MLCT) absorption band maximum of the complex at 445 nm. The effects of pH, ionic strength, and polarity of the mobile phase as well as the complex concentration on the selectivity and resolution have also been studied.     

New ruthenium(II) complexes functionalized with coumarin derivatives: synthesis, energy-transfer-based sensing of esterase, cytotoxicity, and imaging studies

Two new bichromophoric ruthenium(II) complexes, [Ru(bpy)(2)(bpy-CM)](PF(6))(2) and [Ru(bpy)(2)(bpy-CM343)](PF(6))(2) (bpy=2,2'-bipyridine, CM=coumarin) with appended coumarin ligands have been designed and synthesized. The energy-transfer-based sensing of esterase by the complexes has been studied by using UV/Vis and luminescence spectroscopic methods. The cytotoxicity and the cellular uptake of one of the complexes have also been investigated.     

极大高阶交换子的端点估计

该文主要确立了当b∈BMO 时, 极大高阶奇异积分算子交换子T_{b, m}* 满足如下不等式 |{y∈Rⁿ:T_{b, m}*f(y)>λ}|≤C||b||^m_BMO∫_Rⁿ|f(y)|/λ (1+log⁺|f(y)|/λ)^mdy 且T_{b, m}* 在L^p(Rⁿ)(1 < p <∞上有界.     

A New Method for High-Resolution NMR Spectra in Inhomogeneous Fields with Efficient Solvent Suppression

High-resolution nuclear magnetic resonance （NMR） is one of the most powerful tools for analyzing molecular structures and dynamics. Magnetic field homogeneity is required for conventional high-resolution spectra. However, there are many chemical and/or biological circumstances where the spatial homogeneities of the magnetic fields are degraded. Intense solvent signal is another obstacle for obtaining high-resolution spectra, especially in in vivo and in situ NMR spectroscopy. In this paper, a new pulse sequence based on intermolecular multiple quantum coherence （iMQC） was reported. This sequence can effectively remove the effect of magnetic field inhomogeneity and suppress the solvent signal. It can recover the spectral information such as chemical shifts, coupling constants, multiplet patterns, and relative peak areas in inhomogeneous fields. Theoretical analyses and experimental verifications are presented to demonstrate the feasibility of this method.     

High electrochemiluminescence of a new water-soluble iridium(III) complex for determination of antibiotics

A new water-soluble iridium(III) diimine complex with appended sugar was synthesized and characterized. The electrochemiluminescent behavior of the new complex in aqueous buffer was first studied and the ECL signal was found to be much higher than that of [Ru(bpy)(3)](2+) at a Pt working electrode. Tri-n-propylamine (TPA) and antibiotics were determined by the ECL of the iridium(III) complex in aqueous buffer at the Pt electrode and the method was found to show good sensitivity and reproducibility. The new iridium(III) complex was found to display good solubility in aqueous solution and a strong ECL signal at the Pt electrode, which might open up the possibility of its application in analysis.