Not too close for comfort: Practical chiral organocatalysts like that shown promote Michael addition reactions of a wide range trisubstituted carbon nucleophiles to various nitroalkenes, often with nearly perfect stereoselectivity (>99 % ee and >98:2 d.r.). In one step adjacent carbon- or heteroatom-substituted quaternary tertiary stereocenters are generated from readily available starting materials. Supporting information this article is on the WWW under...

A visible near-infrared chemosensor (MCy-1) for mercury ions was successfully devised and characterized. large red-shift (122 nm) of the absorption maximum MCy-1 observed. An important feature new is its high selectivity towards over other competitive species, making "naked-eye" detection possible.

We report the manipulation of hydrogen-bonding-based cooperative catalysis to control diastereoselectivity for a tandem asymmetric reaction creating two nonadjacent stereocenters. This ability both enantioselectivity and allows, first time, direct stereoselective construction 1,3-tertiary−quaternary stereocenters in any possible four configurations from same prochiral precursors with catalytic control. The synthetic consequence such catalyst-controlled is illustrated by synthesis manzacidin...

We examine the correlations of dipole moment and conformational stability to self-assembly solar cell performance within a series isomorphic, solution-processable molecules. These charge-transfer chromophores are described by D(1)-A-D-A-D(1) structure comprising electron-rich 2-hexylbithiophene 3,3'-di-2-ethylhexylsilylene-2,2'-bithiophene moieties as donor units D(1) D, respectively. The building blocks 2,1,3-benzothiadiazole (BT) [1,2,5]thiadiazolo[3,4-c]pyridine (PT) were used...

The regioregular narrow band gap (E(g) ~1.5 eV) conjugated polymer PIPCP was designed and synthesized. contains a backbone comprised of CPDT-PT-IDT-PT repeat units (CPDT = cyclopentadithiophene, PT pyridyl[2,1,3]thiadiazole, IDT indacenodithiophene) strictly organized orientations, such that the pyridyl N-atoms point toward CPDT fragment. Comparison with regiorandom counterpart PIPC-RA illustrates higher level molecular order translates to power conversion efficiencies (PCEs) when...

A long standing question in organic electronics concerns the effects of molecular orientation at donor/acceptor heterojunctions. Given a well-controlled bilayer system, we uncover genuine on charge generation and recombination. These are studied through point view photovoltaics-however, results have important implications operation all optoelectronic devices with interfaces, such as light emitting diodes photodetectors. Our findings can be summarized by two points. First, donor molecules...

Catalytic tandem asymmetric reactions constitute a powerful strategy for the construction of nonadjacent stereocenters in acyclic molecules directly from achiral precursors. In this Communication, we report highly enantioselective and diastereoselective addition trisubstituted carbon donors to 2-chloroacrylonitrile catalyzed by bifunctional cinchona alkaloid catalysts. This represents first conjugate addition−protonation with efficient catalytic control two stereocenters. As demonstrated...

The synthesis and sensing characteristics of a new class colorimetric fluorometric dual-modal probe for mercury ion are outlined. Judicious placement two dithia-dioxa-aza macrocycles on the BODIPY chromophore generates this interesting molecule. A highly Hg2+-selective fluorescence enhancing property (>7-fold) in conjunction with visible change from purple to red-pink can be observed, leading potential fabrication both "naked-eye" ratiometric fluorescent detection Hg2+.

In this communication, we describe the development of first highly enantioselective catalytic conjugate addition to vinyl sulfones. Promoted by readily accessible organocatalysts derived from C6'−OH cinchona alkaloid derivatives and under mild, air- moisture-tolerant conditions, additions a wide range α-cyanoacetates bearing either an α-aryl or α-alkyl substituent sulfones proceeded in excellent enantioselectivity high yield. Consequently, efficient operationally simple C−C bond forming...

A novel fluorescent probe that possess both BODIPY and Rhodamine moieties has been designed for the selective detection of Hg2+ Ba2+ ions on controlling by a logic gate. The characteristic fluorescence Ba2+-selective OFF−ON Hg2+-selective bathochromic shift can be observed, concept used to construct combinational circuit at molecular level. These results will useful further design mimic function complex gates controlling.

A highly efficient asymmetric conjugate addition of carbonyl donors to α,β-unsaturated aldehydes is realized with 6′-OH cinchona alkaloids as bifunctional organocatalysts. wide range α-substituted β-ketoesters and α-cyanoacetates can be employed donors, whereas acrolein β-substituted are suitable acceptors for this enantioselective addition. Supporting information article available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z600867_s.pdf or from author. Please note: The...

Increases in the molecular length of narrow band gap conjugated chromophores reveal potentially beneficial optical and electronic properties, thermal stabilities, high power conversion efficiencies when integrated into optoelectronic devices, such as bulk heterojunction organic solar cells. With objective providing useful information for understanding transition from small-sized molecules to polymers, well a general chemical design platform extracting relationships between structure we set...

An intramolecular charge-transfer (ICT) compound, (TCBD)2OPV3, has been synthesized and fabricated into one-dimensional nanotubes by a reprecipitation method. The observation of SEM TEM showed the were formed from their zero-dimensional precursors hollow nanospheres. Reconstruction was found to happen during morphology transition progress. reconstruction are proposed be "curvature strain releasing" process driven donor-acceptor dipole-dipole interactions. aggregation-induced emission (AIE)...

The influence of extending the molecular length donor-acceptor chromophores on properties relevant to organic optoelectronic devices has been studied by using two new narrow-band-gap systems. Most significantly, we find that higher weight systems exhibit thermal stabilities (beyond 200 °C) when introduced into field effect transistor devices. It is also possible fabricate bulk heterojunction solar cells PC(61)BM with power conversion efficiencies >6%. These high values are not heavily...

An arylated-carbazole conjugated polymer with a deep HOMO level has been developed. Solar cells based on blends of PCX3 and PC71BM show efficiency 3.9% Voc 0.96 V. The device performance can be improved to 5.1% by using polar solvent treatment, most likely as result modified interfacial properties.

High-efficiency bulk heterojunction (BHJ) organic solar cells with power conversion efficiencies of more than 5 % can be fabricated using the green solvent 2-MeTHF. The active layers comprise a blend molecular semiconductor donor intermediate dimensions (X2) and soluble fullerene derivative [6,6]-phenyl-C61 -butyricacidoctylester (PC61 BC8 ). A switch processing from chloroform to 2-MeTHF leads no negative impacts on morphology charge-transport properties optimally performing BHJ films....

For long-term performance, chemically robust materials are desired for organic solar cells (OSCs). Illuminating neat films of OSC in air and tracking the rate absorption loss, or photobleaching, can quickly screen a material's photochemical stability. In this report, we photobleach including polymers, solution-processed oligomers, small molecules, vacuum-deposited molecules. Across test, observe photobleaching rates that span 7 orders magnitude. Furthermore, find film morphology any...

Recently, electrospinning (ESP) has been widely used as a synthetic technology to prepare nanofibers with unique properties from various raw materials. The applications of functionalized have gradually developed into one the most exciting topics in field materials science. In this review, we focus on preparation multi-structure fibrous nanomaterials by means multi-fluidic ESP and review energy, catalysis, biology. First, working principle process are introduced; then, demonstrate how...

Abstract Graphene, due to its exceptional optoelectronic characteristics, high charge carrier mobility, wide absorption band, strong light‐matter interactions, and adjustable nature, has attracted a lot of interest. In light this, an attempt was made successfully deposit graphene on silicon substrate. This results in the formation Schottky junction, which could extend operation window graphene/silicon hybrid device near‐infrared (NIR) region. Furthermore, since photodetectors built with Van...

Identification of the pollution source surface water in a chemical park was difficult because many industrial enterprises with complex wastewater components and similar characteristics are located there. Therefore, national-level Jiaxing City studied, samples from ten batches seven key were collected analyzed using 3D excitation emission matrix spectrometry （EEMS） gas chromatography-mass （GC-MS）. Parallel factor analysis used to extract common EEMS spectra different drainage same enterprise...

Chirale Organokatalysatoren wie der gezeigte katalysieren Michael-Additionen einer Vielzahl von trisubstituierten Kohlenstoffnucleophilen an Nitroalkene, häufig mit fast perfekter Stereoselektivität (>99 % ee und >98:2 d.r.). In einem Schritt werden benachbarte quartäre tertiäre Stereozentren nur Kohlenstoff- oder auch Heteroatomsubstituenten aus einfach zugänglichen Ausgangsverbindungen erhalten. Supporting information for this article is available on the WWW under...

A novel route has been developed for surfactant-free synthesis of highly fluorescent gold quantum dots (GQDs) in N,N-dimethylformamide (DMF). The as-prepared GQDs show instinctive fluorescence and good solubility water. formation mechanism functionalization were investigated by UV−vis spectra, excitation emission mass TEM observation. Ligand-dependent optical properties functionalized found to be dramatically different. approach provides a facile method bare further applications, such as...

Tuberculosis is a life‐threatening chronic infectious disease, which primarily affects the lungs but can spread to other vital organs. The re‐emergence and wide of new virulent forms Mycobacterium tuberculosis that are resistant some or all first second line antitubercular agents has reached an alarming level in recent decades. Thus, it imperative develop more effective agents. Isatin derivatives endowed with diverse biological properties, therefore thousands isatin have been synthesized...