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A hydrophobic compound, which we name 3C18-Azo, containing an azo head and three 18 C alkyl chains has the capacity to form an amphiphile by capping it with a cyclodextrin (CD) by inclusion complexation. The amphiphilic compound self-assembles into vesicles in water. Optical switching of the assembly and disassembly is realized by alternating visible and UV irradiation, which causes the isomerization of the azo groups, thus affecting their complexation with the CDs.

The novel tricyclic heterocycles of 4,5-dihydro[1,2,4]triazolo[3,2- D][1,5]benzoxazepine derivatives were prepared by the cycloaddition of the corresponding bicyclic cationic 1,3-dipoles, which were easily generated from the azoacetates by reaction with AlCl 3 as a Lewis acid, to the triple bond of nitriles along with the consecutive ring expansion. The formation of products deviating from the normal reaction aptitudes was observed and the mechanistic aspects are discussed herein. Crystal diffraction analysis for two of the products unequivocally established the respective structures proposed.

Derivatives of two new heterocyclic systems, namely furo[3,2-c][1,2,4]triazolo[1,5-a]azepinium salts and furo[2,3-f][1,2,4]triazolo[1,5-a]azepinium picrates, were synthesized from bicyclic azo compounds and nitriles in the presence of antimony pentachloride or aluminum chloride. The crystal diffraction analysis of an example product is reported and confirms the structure.

A series of 2-acyl-2H-1,2,3-diazaphospholes 3 underwent ready 1,3-dipolar cycloaddition reactions with 9-diazofluorenes as the 1,3-dipole, yielding the respective bicyclic phosphiranes 5 or trimers 7 depending on the reaction conditions employed. The reaction is believed to proceed via the formation of the [3+2]-cycloaddition adducts followed by elimination of nitrogen from the cyclic azo moiety. In the case of 3c, the phosphatetraazabicyclooctadiene compound 6 has been isolated with no loss of nitrogen. Likewise, the dipolar cycloaddition reaction of diphenyldiazomethane with the >CP- moiety as the 1,3-dipolarophile gave phosphadiazabicyclohexenes 8 in 32–68% yields.

A series of 2-acyl-2 H-1,2,3-diazaphospholes underwent readily 1,3-dipolar cycloaddition reactions with 9-diazofluorenes as the 1,3-dipole, yielding the respective bicyclic phosphiranes or trimers depending on the reaction conditions employed.

A novel palladium catalyst supported on the Nafion membrane, reinforced with poly(tetrafluoroethylene) fiber, has been prepared. The catalyst exhibits high activity and stability in the Heck arylation reactions of aryl iodides with olefins and Sonogashira couplings with phenylacetylene, and can be readily recovered and reused twenty times without significant loss of activity.

The synthesis of a series of novel tricyclic O,N‐heterocycles 7a–k, a kind of unprecedented 2‐oxo‐[1,2,4]triazolo[3,2‐d][1,5]benzoxazepine derivatives, has been accomplished, featuring acid‐induced ring closure of the geminal arylazo isocyanato compounds 5, which were prepared from chroman‐4‐ones in three steps, followed by feasible ring expansion and basic work‐up.

A synthetic approach to the previously unknown thieno[2,3-f][1,2,4]triazolo[1,5-a]azepine derivatives was efficient-ly accomplished by cycloaddition of the bicyclic 1-aza-2-azoniaallene salts 6, derived from 6,7-dihydrobenzo[b]thiophen-4(5H)-one hydrazones 4, to the triple bond of nitriles, followed by ring enlargement. The X-ray crystal diffraction analysis of the picrate 10a provided affirmative proof for the structural assignment made.

Bis(tributyltin)-initiated atom transfer cyclization reactions of 3-butenyl iodoalkanoates in the presence of BF3·OEt2 as the catalyst afforded the 6-exo cyclization products as a mixture of 3,4-cis- and trans-substituted tetrahydro-2H-pyran-2-ones in 53−71% yield with the major isomers being the cis ones. Ab initio calculations at the B3LYP/6-31G* level on the transition states of the radical cyclization and on the cyclized products revealed that the reactions are kinetically controlled and the transition states for the 6-exo radical cyclization are in boat conformations. Moreover, the cis-oriented transition states are of lower energy than the corresponding trans-oriented ones, which are in excellent agreement with experimental results.

[reaction: see text] Alpha-pyrone derivatives were synthesized via the base catalyzed or promoted reaction of 1,2-allenyl ketones and electron-withdrawing group substituted acetates. The reaction was believed to proceed through a Michael addition C-C double-bond migration-lactonization process.

The title compound, C38H32BrNO6, is a new photochromic tetrahydroazepinoisoquinoline (THAI). The longest spiro bond [1.589 (4) A] can be broken very easily by UV light, leading to ring opening. This explains the photochromic behaviour.

The title compound, dimethyl 10b'-(4-fluorostyryl)-8',9'-di-methoxy-4-nitro-5',6'-dihydrospiro[9H-fluorene-9,1'(10b'H)-pyrrolo[2,1-a]isoquinoline]-2'.3'-dicarboxylate. C 38 H 31 FN 2 O 8 , is a new photochromic tetrahydroindolizine. One of the C-C bonds at the spiro C atom is very long [1.630 (2) A], thus explaining the photochromic behaviour.

A MEMS electrostatic actuator based on the lever principle, which aims to obtain a large out-of-plane displacement and has a simple structure and fabrication process is presented in this paper. The two-layer lever actuator consists of four individual levers, each of which is actuated by electrostatic attractive force to produce a downward displacement on the short arm of the lever. This displacement is amplified by the lever to achieve a larger upward displacement on the end of the long arm. A theoretical model of the lever actuator is brought forward, based on the energy method, and is verified by finite-element analysis. The discussions about the key factors related to the characteristics of the structure are also included, from which we acquired the structure parameters for fabrication. Compared with previous studies, the theoretical model and the detailed discussions make the analysis of the out-of-plane actuator based on the lever principle more general. An electrostatic actuator 503 × 503 µm with a central mass of 40 × 40 µm is fabricated using a two-layer surface fabrication process. The measured out-of-plane displacement is about 1.45 µm at a voltage of 47 V; more than double the displacement of a conventional electrostatic attractive parallel plate actuator by the same fabrication process. The possible applications of this actuator are micro-switches, micro-capacitors and micro-mirrors in optical communication and adaptive optics systems.

The title compound, 2,2′-(2,4,8,10-tetra­thia­spiro­[5.5]­undec­ane-3,9-diyl­idene)­bis­(propane­di­nitrile), C13H8N4S4, has been designed and synthesized for use as a potential new organic molecular electronic material. The spiro-annulated structure has twofold symmetry and is formed by two equal push–pull ethyl­ene units, with the cyclo­alkyl­thio groups as electron donors and the cyano groups as electron acceptors. The intermolecular S⋯N non-bonded separation within a layer in the lattice is 3.296 (6) A, indicating a strong intermolecular interaction between the cyano groups and the S atoms, while the S atoms in two neighbouring mol­ecules have a shortest S⋯S contact of 3.449 (3) A. In addition, attractive C—H⋯N and C—H⋯S interactions bridge adjacent mol­ecules either within a layer or between layers. In short, these four types of intermolecular interactions combine to form an extended three-dimensional network in the lattice, resulting in a highly ordered array of molecular packing.

Cedranediol, (1R,2R,5S,7R,8R,9S)-2,6,6,8-tetramethyltricyclo­[5.3.11,7.01,5]undecane-8,9-diol, has been synthesized and characterized by X-ray diffraction analysis. It is a new chiral auxiliary for asymmetric homologation.

Bilayer assembled Langmuir-Blodgett (LB) films were prepared with 11-methacrylminoundecanonic acid and stearic acid as the layer materials and the magnitudes and signs of the effective non-linear optical coefficients were studied by the optical second harmonic generation technique. It was found that the polaribilities of these two compounds have opposite signs and their second-order non-linear coefficients were superposed in the bilayer assembled LB films. This simple model offers us a new way to construct LB films with high non-linear polarizabilities by alternating the assembled multilayers. Furthermore, the polymerization of the LB film of 11-methacrylaminoundecanonic acid under irradiation with UV light was also investigated by the attenuated total reflection method.

A new convenient method for epoxidation of olefins by sodium percarbonate — acetic anhydride is reported. It is found that the epoxides in 60–80% yields can be obtained in 18–24 h without ultrasonication. However, higher yields (some nearly quantitative) can be reached only within 1–3 h under ultrasonication. A comparison between the ultrasonicated epoxidations by use of sodium percarbonate and sodium perborate is also made. The experimental results have revealed that ultrasonication plays a main role in accelerating the interaction of both sodium percarbonate and sodium perborate with acetic anhydride, but it does not alter the mechanism of these two epoxidations.

Cyclopropylidene lithium fluorocarbenoid is studied using the ab initio method. 3-21 G is used for geometry calculations and 6-31G * for energies. Its structure is characterized by an unconventional CLiF ring with all ligands of the carbene center in a cone. It isomerizes with a 6.7 kcal/mol barrier. The ring opening to allene occurs in a fashion of disrotation-conrotation with a 16.4 kcal/mol barrier. The reaction mechanism is the same as that of cyclopropylidene, but the transition state arrives earlier and the relative rotation direction of two methylene terminals changes later.

Gem-bramochlorocyclopropanes can be prepared by a convenient method based on the reaction of the mixtures of haloforms and tetrahalomethanes or hexahaloethane with powdered sodium hydroxide.

Under different reaction conditions, sodium perborate/acetic anhydride oxidizes alkenes into oxiranes or vicinal acetoxy alcohols in good yields.

A mixture of the alkenes (I), bromoform (II), and tetrachloromethane (III) in a molar ratio of 2:4:1 is treated with powdered sodium hydroxide under phase-transfer catalytic conditions and ultrasonic irradiation, yielding the 1,1-dihalocyclopropanes (IV) - (VI) with predominance of the mixed products (IV) mentioned in the title.

Under different reaction conditions, sodium perborate/acetic anhydride oxidizes alkenes into oxiranes or vicinal acetoxy alcohols in good yields.