Synthesis of three-component high nuclearity cluster complexes with ruthenium carbido carbonyl clusters as a building block

Treatment of AgNO₃ with the Rh-Ru and Cu-Ru hetero bimetallic clusters, [PPN][RhRu₅C(CO)₁₄(cod)] and [PPh₄]₂[CuRu₆C(CO)₁₆Cl], afforded novel three-component complexes having one silver-, and two silver-bridges between respective cluster units, [PPN]{Ag[RhRu₅C(CO)₁₄(cod)]₂} and [PPh₄]₂{Ag₂[CuRu₆C(CO)₁₆Cl]₂}, respectively. Reaction of the ruthenium-copper cluster [PPh₄]₂{Cu₄[Ru₆C(CO)₁₆]₂Cl₂} (6) with Pd₂(dba)₃ · CHCl₃ gave another three-component cluster [PPh₄]₂{Cu₄Pd₂[Ru₆C(CO)₁₆]₂Cl₂} by incorporation of two palladium atoms. However, a similar reaction of 6 with Pt(dba)₂ gave only a two-component cluster complex, [PPh₄]₂{Pt₂[Ru₆C(CO)₁₅]₂}, while the reaction of silver analog [PPN]₂{Ag₄[Ru₆C(CO)₁₆]₂Cl₂} with Pd₂(dba)₃ · CHCl₃ resulted in the formation of known ruthenium-palladium cluster [PPN]₂{Pd₄[Ru₆C(CO)₁₆]₂}. Treatment of 6 with [RhCl(CO)₂]₂ gave two two-component clusters, [PPh₄][RhRu₅C(CO)₁₆] and [PPh₄]₂{Cu₇[Ru₆C(CO)₁₅]₂Cl₃}. All the new mixed-metal high nuclearity clusters have been characterized by single crystal X-ray analyses.     

Dye-sensitized TiO2 solar cells using imidazolium-type ionic liquid crystal systems as effective electrolytes

A novel ionic liquid crystal (ILC) system (C(12)MImI/I(2)) with a smectic A phase used as an electrolyte for a dye-sensitized solar cell (DSSC) showed the higher short-circuit current density (J(SC)) and the higher light-to-electricity conversion efficiency than the system using the non-liquid crystalline ionic liquid (C(11)MImI/I(2)), due to the higher conductivity of ILC. To investigate charge transport properties of the electrolytes in detail, the exchange reaction-based diffusion coefficients (D(ex)) were evaluated. The larger D(ex) value of ILC supported that the higher conductivity of ILC is attributed to the enhancement of the exchange reaction between iodide species. As a result of formation of the two-dimensional electron conductive pathways organized by the localized I(3)- and I- at S(A) layers, the concentration of polyiodide species exemplified by I(m)- (m = 5, 7, ...) was higher in C(12)MImI/I(2). However, as the increment of the concentration of polyiodide species is less than that of D(ex), the contribution of a two-dimensional structure of the conductive pathway through the increase of collision frequency between iodide species was proposed. Furthermore, a quasi-solid-state ionic liquid crystal DSSC was successfully fabricated by employing a low molecular gelator. Addition of the 5.0 g/L gelator to ILC improved light-to-electricity conversion efficiency through the increase of J(SC) due to the enhancement of the conductivity in C(12)MImI/I(2)-gel.     

Local lamellar structures in banded spherulites analyzed by three‐dimensional electron tomography

The lamellar morphology in banded spherulites of poly(ε‐caprolactone) blended with an amorphous polymer, poly(vinyl butyral), was investigated by three‐dimensional transmission electron tomography. It showed a local lamellar twist on a smaller scale than the band spacing by 2 orders of magnitude. It also indicated wavy lamellae and frequent variation in the direction of the lamellar plane. All these results indicated an S‐profiled lamellar structure; that is, the cross section perpendicular to the lamellar growth direction was S‐shaped. S‐profiled lamellae show these structures when they are sliced at a certain angle to the lamellar surface direction. Lamellar branching was also observed, but no screw dislocations that led to the formation of extinction rings were observed in this work. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1122–1125, 2007     

PAMAM dendrimer composite membrane for CO2 separation: Formation of a chitosan gutter layer

A poly(amidoamine) (PAMAM) dendrimer composite membrane with an excellent CO₂/N₂ separation factor was developed in-situ. The In-situ Modification (IM) method was used to modify the surface of commercial porous membranes, such as ultrafiltration membranes, to produce a gas selective layer by controlling the interface precipitation of the membrane materials in the state of a received membrane module. Using the IM method, a chitosan layer was prepared on the inner surface of a commercially available ultrafiltration membrane as a gutter layer, in order to affix PAMAM dendrimer molecules on the porous substrate. After chitosan treatment, the PAMAM dendrimer was impregnated into the gutter layer to form a PAMAM/chitosan hybrid layer. The CO₂ separation performance of the resulting composite membrane was tested at a pressure difference of 100 kPa and a temperature of 40 °C, using a mixed CO₂ (5 vol%)/N₂ (95 vol%) feed gas. The PAMAM dendrimer composite membrane, with a gutter layer prepared from ethylene glycol diglycidyl ether and a 0.5 wt% chitosan solution of two different molecular weight chitosans, revealed an excellent CO₂/N₂ separation factor and a CO₂ permeance of 400 and 1.6 × 10⁻⁷ m³ (STP) m⁻² s⁻¹ kPa⁻¹, respectively. SEM observations revealed a defect-free chitosan layer (thickness 200 nm) positioned directly beneath the top surface of the UF membrane substrate. After PAMAM dendrimer treatment, the hybrid chitosan/PAMAM dendrimer layer was observed with a thickness of 300 nm. XPS analysis indicated that the hybrid layer contained about 20–40% PAMAM dendrimer.     

Photoregulation of the Formation and Dissociation of a DNA Duplex by Using the cis–trans Isomerization of Azobenzene

The duplex-forming activity of an oligonucleotide has been photoregulated by making use of the isomerization of an azobenzene moiety in the side chain. When the azobenzene moiety is isomerized from the trans form to the cis form upon photoirradiation, the melting temperature of the duplex between the oligonucleotide and its complementary counterpart is significantly lowered, and the duplex is largely dissociated into two single-stranded oligonucleotides (shown schematically).     

新型糖基聚合物的合成及其作为高效液相色谱手性固定相的应用(英文)

Two novel polymers containing glucose units as the main-chain that only differ in terms of their regioregularity were synthesized to evaluate their chiral recognition abilities as chiral stationary phases(CSPs)for high performance liquid chromatography(HPLC).The regioregular polymer(poly-5)shows clear resolution ability for the racemate of cobalt(Ⅲ)acetylacetonate(Co(acac)3),whereas the corresponding regioirregular polymer(poly-3)does not show any chiral recognition for Co(acac)3.The regioregular polymer main-chain seems to play an important role not only in providing an efficient interaction with the racemate but also in expressing the chiral recognition ability as a CSP for HPLC.     

Triply Linked Corrole Dimers

The oxidation of 10–10′ singly linked corrole dimers with DDQ at low concentration in CHCl₃ afforded meso–meso, β–β, β–β triply linked 2H‐corrole dimers (with two inner NH groups in each corrole unit), which exhibited characteristic ¹H NMR and absorption spectra attributable to their nonaromatic electronic networks. These 2H‐corrole dimers were reduced with NaBH₄ to aromatic 3H‐corrole dimers, which were unstable and easily oxidized back to the 2H‐corrole dimers upon exposure to air. Bis(zinc(II)) complexes of the 2H‐corrole dimers were synthesized and characterized as rare examples of nonaromatic zinc(II) corrole complexes.     

A syn‐Selective Aza‐Aldol Reaction of Boron Aza‐Enolates Generated from N‐Sulfonyl‐1,2,3‐Triazoles and 9‐BBN‐H

A syn‐selective aza‐aldol reaction of boron aza‐enolates, generated from N‐sulfonyl‐1,2,3‐triazoles and 9‐BBN‐H, is reported. It provides a sequential one‐pot procedure for the stereoselective construction of 1,3‐amino alcohols, having contiguous stereocenters, starting from terminal alkynes.     

Addition reaction of spiro orthoesters with electrophiles: A model reaction for the development of novel polyaddition accompanying ring-opening isomerization

The addition reaction of spiro orthoesters (SOEs) with electrophiles accompanying ring-opening isomerization was investigated as a model reaction for polyaddition of bifunctional SOEs with bifunctional electrophiles. Among several electrophiles such as carboxylic acids and carboxylic anhydrides, acid halides showed particularly high reactivities to SOEs. An equimolar reaction of SOEs with acid chlorides took place selectively, leading to the corresponding 1 : 1 adducts. SOEs with seven-membered cyclic ether rings—1,4,6-trioxaspiro[5.6]undecane derivatives—showed higher reactivities than SOEs with six- and five-membered cyclic ether rings. The reaction accompanied zero shrinkage in volume. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4502–4509, 1999