Synthesis of Rigid and Optically Active Bis(binaphthyl) Cyclic Compounds

Optically active cyclic bis(binaphthyl)s (4a–d), which are composed of aromatics, ethers, and ketonic carbonyls, were synthesized through a two‐step nucleophilic aromatic substitution reaction. Bis(binaphthyl) cyclic compounds (4a and 4b) were obtained in moderate yields when difluoride 3a and 3b were employed. On the other hand, bis(binaphthyl)s 4c and 4d were scarcely obtained when 3c and 3d were employed.     

Note Copolymerization of Styrene with Maleic Anhydride Initiated by L-Ascorbic Acid

It is well known that maleic anhydride (MAH) behaves as an electron acceptor and forms charge-transfer complexes with donor monomers such as styrene (ST) [1,2], divinyl ether [3], and some of other olefms [4–61. The charge-transfer polymerization of ST with MAH has been extensively studied [1,7–11]. On the other hand, L-ascorbic acid (L-Asc) in combination with a suitable oxidants proved to be an efficient redox initiator for various vinyl polymerizations. Misra et al. [12] showed that the reduction of peroxides by ascorbic acid follows a chain mechanism with ascorbate and other free radicals as intermediates. Thus, we can expect that such an electron donor might initiate the copolymerization of MAH with ST.     

Functionalization of ‘kite’ shaped styryl end-capped benzodithiophene with ketone groups: synthesis, characterization and properties

We report the synthesis of a new bridged end-capped distyryldithiophene with ketone groups on the bridge: E,E-2,7′-bis((2-phenyl)-ethenyl)-benzo[2,1-b:3,4-b′]dithiophene-4,5-dione 1. Optical and electrochemical properties of 1 in solution were investigated by UV-vis absorption and cyclic voltammetry and compared to the unsubstituted parent molecule (KDS2T). Morphology of 1-based thin films was investigated by scanning electron microscopy (SEM) and the crystalline structure characterization by X-ray diffraction (XRD). Thin films were implemented as active layers into organic thin-film transistors (OTFT) in top contact configuration to evaluate the charge transport properties.     

Selective synthesis of functionalized allylic compounds by Pd(0)-catalyzed three-component reaction of methyl propargyl carbonate with phenols and nucleophiles

A Pd(0)-catalyzed three-component reaction of methyl propargyl carbonate with phenols and nucleophiles is described. The reaction proceeded smoothly and various allylic compounds were synthesized selectively in good to excellent yields under neutral conditions. The regioselective introduction of functional groups into the allylic compounds could also be achieved. The reaction with nitrogen and carbon nucleophiles afforded mainly 2-aryloxyallylic compounds. On the other hand, aliphatic alcohols gave 2-alkoxyallylic compounds.     

Synthesis and characterization of ethylbis(2-pyridylethyl)amineruthenium complexes and two different types of C-H bond cleavage at an ethylene arm

Ruthenium complexes bearing ethylbis(2-pyridylethyl)amine (ebpea), which has flexible -C(2)H(4)- arms between the amine and the pyridyl groups and coordinates to a metal center in facial and meridional modes, have been synthesized and characterized. Three trichloro complexes, fac-[Ru(III)Cl(3)(ebpea)] (fac-[1]), mer-[Ru(III)Cl(3)(ebpea)] (mer-[1]), and mer-[Ru(II)Cl(3){η(2)-N(C(2)H(5))(C(2)H(4)py)═CH-CH(2)py}] (mer-[2]), were synthesized using the Ru blue solution. Formation of mer-[2] proceeded via a C-H activation of the CH(2) group next to the amine nitrogen atom of the ethylene arm. Reduction reactions of fac- and mer-[1] afforded a triacetonitrile complex mer-[Ru(II)(CH(3)CN)(3)(ebpea)](PF(6))(2) (mer-[3](PF(6))(2)). Five nitrosyl complexes fac-[RuX(2)(NO)(ebpea)]PF(6) (X = Cl for fac-[4]PF(6); X = ONO(2) for fac-[5]PF(6)) and mer-[RuXY(NO)(ebpea)]PF(6) (X = Cl, Y = Cl for mer-[4]PF(6); X = Cl, Y = CH(3)O for mer-[6]PF(6); X = Cl, Y = OH for mer-[7]PF(6)) were synthesized and characterized by X-ray crystallography. A reaction of mer-[2] in H(2)O-C(2)H(5)OH at room temperature afforded mer-[1]. Oxidation of C(2)H(5)OH in H(2)O-C(2)H(5)OH and i-C(3)H(7)OH in H(2)O-i-C(3)H(7)OH to acetaldehyde and acetone by mer-[2] under stirring at room temperature occurred with formation of mer-[1]. Alternative C-H activation of the CH(2) group occurred next to the pyridyl group, and formation of a C-N bond between the CH moiety and the nitrosyl ligand afforded a nitroso complex [Ru(II)(N(3))(2){N(O)CH(py)CH(2)N(C(2)H(5))C(2)H(4)py}] ([8]) in reactions of nitrosyl complexes with sodium azide in methanol, and reaction of [8] with hydrochloric acid afforded a corresponding chloronitroso complex [Ru(II)Cl(2){N(O)CH(py)CH(2)N(C(2)H(5))C(2)H(4)py}] ([9]).     

Superconducting Pb island nanostructures studied by scanning tunneling microscopy and spectroscopy

Superconductivity of nanosized Pb-island structures whose radius is 0.8 to 2.5 times their coherence length was studied under magnetic fields using low-temperature scanning tunneling microscopy and spectroscopy. Spatial profiles of superconductivity were obtained by conductance measurements at zero-bias voltage. Critical magnetic fields for vortex penetration and expulsion and for superconductivity breaking were measured for each island. The critical fields depending on the lateral size of the islands and existence of the minimum lateral size for vortex formation were observed.     

Poly(silamine)s as new electron-beam resist materials

Several types of poly(silamine)s were prepared and their structure-characteristics relationships were investigated. When a phenyl ring in the organosilyl unit and/or a cyclic structure in the amino unit was introduced, the glass transition temperatures were increased significantly in order to increase film formability. From the thermogravimetric analysis of the poly(silamine)s, it was found that the thermal decomposition of poly(silamine)s starts at ca. 380–400°C. On electron-beam irradiation of the poly(silamine) films, degradation of the polymer took place. On the basis of these results, poly(silamine)s can be one of the candidates for new positive-type polymeric resists.