Synthesis of new fluorene-based copolymers containing an anthracene derivative and their applications in polymeric light-emitting diodes.

We report the synthesis of copolymers containing fluorene and highly soluble anthracene derivatives, of general formula, poly{9,9'-bis-(4-octoloxy-phenyl)-fluorene-2,7-diyl-co-9,10-bis-(decy-1-ynyl)-anthracene-2,6-diyl}s (PFAnts). The PFAnts were synthesized via Suzuki coupling and the feed ratios of the anthracene derivative (Ant) were 1, 5, 10, 30, and 50 mol % of the total amount of monomer. PFAnts showed well-defined high molecular weights and were more soluble in conventional organic solvents.

Photoactive diazoketo-functionalized self-assembled monolayer for biomolecular patterning.

A diazoketo-functionalized alkoxysilane compound was synthesized, and its self-assembled monolayer (SAM) formation was studied on glass and silicon substrates. Infrared spectroscopy was employed to follow the photoreaction in this system, which proved that carboxylic groups were generated from diazoketo groups in the surface of the substrate. Photopatterning of biotin/streptavidin on the diazoketo-functionalized SAM shows the potential of this novel platform for biomolecular patterning.

Construction of protein-resistant pOEGMA films by helicon plasma-enhanced chemical vapor deposition.

This paper describes the formation of protein-resistant, poly(ethylene glycol) methyl ether methacrylate (pOEGMA) thin films by helicon plasma-enhanced chemical vapor deposition (helicon-PECVD). pOEGMA was successfully grafted onto a silicon substrate, as a model substrate, without any additional surface initiators, by plasma polymerization of OEGMA. The resulting pOEGMA films were characterized by ellipsometry, FT-IR spectroscopy, X-ray photoelectron spectroscopy and contact angle goniometry.

Dual patterning and sequential functionalization of block copolymers using photocrosslinkable random copolymer film.

A novel method of dual patterning and sequential functionalization of block copolymers is proposed using a photocrosslinkable random copolymer film, poly(styrene-r-(tert-butyl acrylate)-r-(cinnamoyloxyethyl acrylate)). The tert-butyl esters of the block copolymer, polystyrene-block-poly(tert-butyl acrylate), coated on the patterned random copolymer film were sequentially deprotected to give carboxylic acids using an acid catalyst and heat treatment. The sequentially produced carboxylic acid patterns were used for the sequential patterning of gold nanoparticles as an example of potential applications.

Spin-orbit and electron correlation effects on the structure of EF3 (E = I, At, and element 117).

Structures and vibrational frequencies of group 17 fluorides EF3 (E = I, At, and element 117) are calculated at the density functional theory (DFT) level of theory using relativistic effective core potentials (RECPs) with and without spin-orbit terms in order to investigate the effects of spin-orbit interactions and electron correlations on the structures and vibrational frequencies of EF3. Various tests imply that spin-orbit and electron correlation effects estimated presently from Hartree-Fock (HF) and DFT calculations with RECPs with and without spin-orbit terms are quite reasonable. Spin-orbit and electron correlation effects generally increase bond lengths and/or angles in both C2v and D3h structures.

Mass spectrometry assisted lithography for the patterning of cell adhesion ligands on self-assembled monolayers.

Pattern of events: A simple and flexible method has been developed for patterning cell adhesion ligands. Locally erasing self-assembled monolayers with tri(ethyleneglycol) groups on a gold substrate by using a MALDI-TOF MS nitrogen laser and filling the exposed gold surface with an alkanethiol presenting carboxylic acid groups enables subsequent immobilization of maleimide and a cell adhesion peptide, which can then recognize cells (see scheme).

Shape auxiliary approach for carboxylate-functionalized gold nanocrystals.

A shape auxiliary approach for the synthesis of shape-controlled gold nanocrystals with functional moieties is established; carboxylate-functionalized gold polyhedra were successfully synthesized in a one-pot reaction in the presence of poly(dimethylaminoethyl methacrylate), which contains the dimethylaminoethyl group as a shape auxiliary.

A new entry of copper-catalyzed four-component reaction: facile access to alpha-aryl beta-hydroxy imidates.

Alpha-aryl beta-hydroxy imidates are efficiently obtained by the four-component reaction of ethyl glyoxylates, aryl acetylenes, sulfonyl azides, and alcohols using a copper catalyst. The developed procedure is characterized by high selectivity, mild reaction conditions, a wide substrate scope, and an excellent functional group tolerance. Facile transformations of the obtained sulfonylimidate moiety to other carbonyl groups such as sulfonamides or esters were also demonstrated.

Biomimetic approach to the formation of magnetic nanoparticle/silica core/shell structures.

We report a mild method for constructing magnetic iron oxide nanoparticle (IONP)/silica core/shell hybrid structures by biomimetic silicification of silicic acids. 2-(Dimethylamino)ethyl methacrylate (DMAEMA) was grafted onto the surface of IONPs via surface-initiated, atom transfer radical polymerization, and then silica shells were subsequently formed by biomimetic polycondensation of silicic acids with poly(DMAEMA) as an organic template for the formation of silica structures. The resulting IONP/silica hybrids were characterized by Fourier-transform infrared spectroscopy and transmission electron microscopy.

Rapid and reversible gel-sol transition of self-assembled gels induced by photoisomerization of dendritic azobenzenes.

An asymmetric bis-dendritic gelator (1) consisting of an azobenzene dendron and an aliphatic amide dendron was synthesized to achieve a photoresponsive self-assembly. The compound gelled in a wide range of organic solvents, even at concentrations as low as 0.02% (w/v) in cyclohexane.

Bio-inspired silicification on patterned surfaces generated by microcontact printing and layer-by-layer self-assembly.

Micropatterns of silica were generated under biocompatible conditions by a combination of microcontact printing (muCP), layer-by-layer (LbL) self-assembly, and biomimetic silicification. Quaternary amine-containing poly(diallyl dimethyl ammonium chloride) induced polycondensation of silicic acid, resulting in spatioselective formation of silica micropatterns. Scale bar: 10 microm.

Utilization of evaporation during the crystallization process: self-templation of organic parallelogrammatic pipes.

Analogues of 4-dodecyloxy-2-trifluoromethylbenzamide (12FH2) consisting of a hydrophobic alkyl chain, a trifluoromethylated aromatic ring, and a self-complementary hydrogen-bonding amido group were synthesized, and the structural effect of each component on the formation of parallelogrammatic pipes was investigated. Differential scanning calorimetry and powder XRD analyses revealed that all-trans L and gauche-rich S polymorphic forms appeared for the analogues with more than eight carbon atoms in the alkyl chain, that is, the polymorphism originates in the conformation of the alkyl groups and hydrogen-bonding patterns of the benzamide group. Also, the trifluoromethyl substituent is crucial in that it provides an appropriate molecular balance between the benzamide and alkyl groups.

Copper-catalyzed reaction of alpha-aryldiazoesters with terminal alkynes: a formal [3 + 2] cycloaddition route leading to indene derivatives.

It was discovered that Cu(IPr)Cl-catalyzed reaction of terminal alkynes with alpha-aryldiazoacetates provides indene derivatives, formal [3 + 2] cycloaddition adducts. Excellent regio- and chemoselectivity were observed to afford either 3H- or 1H-indene esters depending on the reaction conditions employed. The reaction is proposed to proceed via tandem processes: alkyne insertion into copper-carbenoid, intramolecular electrophilic attack on the aromatic ring, and then isomerization.

Asymmetrically functionalized, four-armed, poly(ethylene glycol) compounds for construction of chemically functionalizable non-biofouling surfaces.

Asymmetrically functionalized, four-armed, Tween 20 derivatives that formed stable monomolecular films on solid substrates were designed and synthesized. Thiol-modified Tween 20 was used for forming self-assembled monolayers (SAMs) on gold, and maleimide-modified Tween 20 was introduced onto SiO(2) surfaces with SAMs of (3-mercaptopropyl)trimethoxysilane through Michael addition. These structurally modified Tween 20 compounds gave the original characteristics of Tween 20, non-biofouling (from ethylene glycol groups) and functionalizable (from OH groups) properties, to each substrate.

Adsorption configuration change of pyridine on Ge(100): dependence on exposure amount.

The variations of adsorption configurations of pyridine on Ge(100) as a function of exposure amount have been studied using high-resolution photoelectron spectroscopy (HRPES). At low exposure the C 1s and N 1s core levels show a single adsorption state of pyridine with N 1s binding energy at 400.85 eV and C 1s binding energies at 286.

Synthesis of condensed pyrroloindoles via Pd-catalyzed intramolecular C-H bond functionalization of pyrroles.

A new strategy for the synthesis of condensed hetero- or carbocycles such as pyrroloindoles or fluorenes has been developed that involves the Pd-catalyzed cyclization of readily available N-(2-halobenzyl)pyrroles or their phenyl derivatives. The reaction is proposed to proceed via oxidative addition of benzylic halides to Pd(0) followed by base-assisted C-H bond activation. A broad range of condensed cyclic products could be obtained in good to excellent yields under mild conditions.

Biomimetic approach to the formation of titanium dioxide thin films by using poly(2-(dimethylamino)ethyl methacrylate).

We demonstrate that the biomimetic method-which has been used for the formation of silica thin films-also could be applied directly to the formation of titanium dioxide (TiO(2)) thin films, which are technologically important materials because of their applications to photocatalytic purifiers, photochemical solar cells, and others. After generation of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) films on gold surfaces by surface-initiated polymerization, titanium bis(ammonium lactato)dihydroxide was used as a precursor of TiO(2). The TiO(2)/PDMAEMA films were successfully formed on the surfaces in aqueous solution at neutral pH (pH 6.

Synthetic utility of ammonium salts in a Cu-catalyzed three-component reaction as a facile coupling partner.

Ammonium salts were found to be a convenient and inexpensive reagent in the Cu-catalyzed three-component reaction with terminal alkynes and sulfonyl or phosphoryl azides leading to N-unprotected amidines. Thus obtained amidines bearing 2-bromobenzenesulfonyl moiety were efficiently cyclized by the Cu-catalyzed intramolecular N-arylation to give an important pharmacophore skeleton of 2H-1,2,4-benzothiadiazine 1,1-dioxides. Conveniently, two tandem catalytic procedures could be readily operated in one pot.

Disorder-order phase change of omega-(N-pyrrolyl)alkanethiol self-assembled monolayers on gold induced by STM scans and thermal activation.

Molecular ordering of pyrrolyl-terminated alkanethiol self-assembled monolayers (PyC(n)SH SAMs) on Au(111) substrates (n = 11 or 12) was investigated by scanning tunneling microscopy (STM) and various spectroscopic methods. The SAMs, which were in a disordered state when formed at room temperature, could be ordered either globally by thermal annealing at 70 degrees C, or locally via stimulation with repetitive STM scans. The ordered phase was characterized by small domains of molecular rows formed along 112[combining macron] directional set with an inter-row corrugation period close to 1.

Ammonium salts as an inexpensive and convenient nitrogen source in the Cu-catalyzed amination of aryl halides at room temperature.

Convenient and inexpensive ammonium salts such as NH(4)Cl and aqueous NH(3) solution are found to be readily utilized in the Cu-catalyzed room temperature N-arylation of aryl halides, providing N-unprotected aniline derivatives in high yields.

Direct observation of the primary and secondary C-Br bond cleavages from the 1,2-dibromopropane photodissociation at 234 and 265 nm using the velocity map ion imaging technique.

Photodissociation dynamics of 1,2-dibromopropane has been investigated at 234 and 265 nm by using the velocity map ion imaging method. At both pump energies, a single Gaussian-shaped speed distribution is observed for the Br*((2)P(1/2)) fragment, whereas at least three velocity components are found to be existent for the Br((2)P(3/2)) product. The secondary C-Br bond cleavage of the bromopropyl radical which is energized from the ultrafast primary C-Br bond rupture should be responsible for the multicomponent translational energy distribution at the low kinetic energy region of Br((2)P(3/2)).

Structure-activity relationship studies of the chromosome segregation inhibitor, Incentrom A.

A series of Incentrom A analogs that inhibit the chromosome segregation process in yeast were synthesized and tested for their effects on chromosome stability and cell proliferation. Pharmacophore and structure-activity relationship of Incentrom A for the anti-yeast activity were established.

Palladium-catalyzed C-H functionalization of pyridine N-oxides: highly selective alkenylation and direct arylation with unactivated arenes.

Two catalytic protocols of the oxidative C-C bond formation have been developed on the basis of the C-H bond activation of pyridine N-oxides. Pd-catalyzed alkenylation of the N-oxides proceeds with excellent regio-, stereo-, and chemoselectivity, and the corresponding ortho-alkenylated N-oxide derivatives are obtained in good to excellent yields. Direct cross-coupling reaction of pyridine N-oxides with unactivated arene was also developed in the presence of Pd catalyst and Ag oxidant, which affords ortho-arylated pyridine N-oxide products with high site-selectivity.

Mechanistic studies on the Cu-catalyzed three-component reactions of sulfonyl azides, 1-alkynes and amines, alcohols, or water: dichotomy via a common pathway.

Combined analyses of experimental and computational studies on the Cu-catalyzed three-component reactions of sulfonyl azides, terminal alkynes and amines, alcohols, or water are described. A range of experimental data including product distribution ratio and trapping of key intermediates support the validity of a common pathway in the reaction of 1-alkynes and two distinct types of azides substituted with sulfonyl and aryl(alkyl) groups. The proposal that bimolecular cycloaddition reactions take place initially between triple bonds and sulfonyl azides to give N-sulfonyl triazolyl copper intermediates was verified by a trapping experiment.