Microstructure and properties of joint of Al/Cu welded by resistance element welding with an auxiliary gasket of Ni.

A rivet of aluminum and auxiliary gasket of nickel were adopted to weld A1060 aluminum plate and T2 copper plate using resistance element welding. The interfacial microstructure was analyzed and the tensile shear load of the joint was tested. A layer of AlCu and the eutectic structure of AlCu and (Al) were formed in the interfacial zone of Al/Cu.

Insight into Regioselective Control in Aerobic Oxidative C-H/C-H Coupling for C3-Arylation of Benzothiophenes: Toward Structurally Nontraditional OLED Materials.

The installation of (benzo)thiophene-containing biaryls via coupling reactions has become a staple in designing photoelectric materials. Undeniably, C-H/C-H cross-coupling reactions between two (hetero)aromatics would be a shortcut toward these structural fragments. While more reliable cross-coupling technologies are well-established to provide C2-arylated (benzo)thiophenes, efficient methods that arylate the C3-position remain underdeveloped.

Molecular engineering enabling reversible transformation between helical and planar conformations by cyclization of alkynes.

Molecular engineering enabling reversible transformation between helical and planar conformations is described herein. Starting from easily available 2-(pyridin-2-yl)anilines and alkynes, a one-pot strategy is set up for the synthesis of aza[4]helicenes two successive rhodium-catalyzed C-H activation/cyclizations. Helical pyrrolophenanthridiziniums can be transformed into planar conformations through the cleavage of acidic pyrrole N-H, leading to turn-off fluorescence.

Regioselective addition/annulation of ferrocenyl thioamides with 1,3-diynes a sulfur-transfer rearrangement to construct extended π-conjugated ferrocenes with luminescent properties.

Herein a regioselective addition/annulation strategy of ferrocenyl (Fc) thioamides with alkynes to construct thienylferrocene (ThienylFc) structures, involving a rhodium-catalyzed C-H activation, an unusual C2-selective addition of 1,3-diyne, and an unexpected intramolecular sulfur-transfer rearrangement process is described. In this protocol, thioamide not only serves as a directing group to activate the -C-H bond of the ferrocene, but also as a sulfur source to form the thiophene ring. The resulting carboxylic ester group after sulfur transfer can act as a linkage to construct extended π-conjugated ferrocenes (OCTFc) with luminescent properties.

Switchable cascade C-H annulation to polycyclic pyryliums and pyridiniums: discovering mitochondria-targeting fluorescent probes.

Disclosed herein is a counterion additive-switched rhodium-catalyzed cascade triple C-H annulation of 4-hydroxy-1-naphthaldehydes with alkynes, in which six chemical bonds are formed in one-pot. This reaction enables the rapid assembly of diverse polycyclic pyrylium and pyridinium fluorophores, which leads to two specific mitochondria-labeling reagents with low cytotoxicity and superior photostability.

Oxidative C-H/C-H Cross-Coupling of [1,2,4]Triazolo[1,5- a]pyrimidines with Indoles and Pyrroles: Discovering Excited-State Intramolecular Proton Transfer (ESIPT) Fluorophores.

A highly efficient Rh(III)-catalyzed oxidative C-H/C-H cross-coupling of [1,2,4]triazolo[1,5- a]pyrimidines (TAP) with indoles and pyrroles has been developed, which provides an opportunity to rapidly assemble a large library of novel excited-state intramolecular proton transfer (ESIPT) fluorophores. The resulting 7-(pyrrol-2-yl)TAPs only show the enol-form emission, while 7-(indol-2-yl)TAPs would undergo an ESIPT process and mainly exhibit the keto-form emission. In highly polar solvents, the enol-form emission of 7-(indol-2-yl)TAPs is enhanced significantly, thus showing the dual emission of enol and keto forms.

Molecular Engineering of Mechanochromic Materials by Programmed C-H Arylation: Making a Counterpoint in the Chromism Trend.

The development of facile methods for screening organic functional molecules through C-H bond activation is a revolutionary trend in materials research. The prediction of mechanochromism as well as mechanochromic trends of luminogens is an appealing yet challenging puzzle. Here, we present a strategy for the design of mechanochromic luminogens based on the dipole moment of donor-acceptor molecules.

A sensitive colorimetric and fluorescent sensor based on imidazolium-functionalized squaraines for the detection of GTP and alkaline phosphatase in aqueous solution.

Imidazolium-functionalized squaraine ImSQ8 is synthesized as a sensitive colorimetric and fluorescent chemosensor for GTP in aqueous solution. The detection limit of GTP reaches 5.4 ppb.

Transition-metal-catalyzed C-H bond functionalizations: feasible access to a diversity-oriented β-carboline library.

Diversification of the β-carboline skeleton has been demonstrated to assemble a β-carboline library starting from the tetrahydro-β-carboline framework. This strategy affords feasible access to heteroaryl-, aryl-, alkenyl-, or alkynyl-substituted β-carbolines at the C1, C3, or C8 position through three categorically different types of transition-metal-catalyzed CC bond-forming reactions, in the presence of multiple potentially reactive positions. These site-selective functionalizations include; 1) the Cu-catalyzed C1/C3-selective decarboxylative C sp 3C sp 2 and C sp 3Csp coupling of hexahydro-β-carboline-3-carboxylic acid with a CH bond of a heteroarene or terminal alkyne; 2) the chelation-assisted Pd-catalyzed C1/C8-selective CH arylation of hexahydro-β-carboline with aryl boron reagents; and 3) the chelation-assisted Pd-catalyzed C1/C3-selective oxidative CH/CH cross-coupling of β-carboline-N-oxide with arenes, heteroarenes, or alkenes.

Palladium-catalyzed tandem N-H/C-H arylation: regioselective synthesis of N-heterocycle-fused phenanthridines as versatile blue-emitting luminophores.

A general and highly regioselective synthetic protocol for structurally diverse N-heteroaryl-fused phenanthridines has been developed. Varieties of fluorescence molecules comprising imidazole-fused, benzoimidazole-fused, indole-fused and pyrrole-fused phenanthridines were obtained by this modular approach, some of which exhibit excellent blue-emitting performance, high quantum yields, long fluorescence lifetimes, interesting electrochemical properties, and thermal stabilities.

Proteome analysis identifies the role of heat stress in production of progeny HCV in Huh7 cells harboring intact HCV.

Objective: The intact hepatitis C virus (HCV) cell culture system has provided a powerful tool for studying the interaction between HCV and host cell. We applied proteomic techniques to globally analyze the protein expression profiles of Huh7 in the absence and presence of HCV, with the aim to elucidate the host cell components response to HCV.

Methods: Proteomic and molecular biology techniques were used for this aim.

[Differential expression of genes related to transcription in cultured hepatoma cells with intact genome of hepatitis C virus].

Objective: To investigate the effects of hepatitis C virus (HCV) on transcription regulation genes of host cells by gene chip assays in cultured cells with intact HCV genome.

Methods: Huh-7 hepatoma cells were cultured and infected with in vitro constructed HCV. The total RNAs, proteins and cell culture supernatants of HCV infected cells and control cells were isolated.