Size-selective encapsulation property of unimolecular reverse micelle consisting of hyperbranched D-glucan core and L-leucine ethyl ether shell

金沢大学理工研究域自然システム学系The synthesis of a unimolecular reverse micelle (3) consisting of hyper-branched D-glucan as the core and L-leucine ethyl ester as the shell was accomplished through the carbamation reaction of the hyperbranched D-glucan (1) with the N-carbonyl L-leucine ethyl ester (2) in pyridine at 100 °C. The polymer 3 was soluble in a large variety of organic solvents, such as methanol, acetone, chloroform, and ethyl acetate, and insoluble in water, which remarkably differed from the solubility of 1. The solubilities of 3 were also changed by the substitution degrees of the L-leucine moiety. The encapsulation ability of 3 toward water-soluble dyes has been investigated. These results indicated that 3 was a unimolecular reverse micelle with an encapsulation ability toward hydrophilic dye molecules. In addition, 3 showed an molecular size-selective encapsulation ability. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Formation kinetics of levoglucosan from glucose in high temperature water

金沢大学理工研究域自然システム学系The application of high temperature water to produce levoglucosan from glucose was studied. The reactions were performed using a tube reactor, and the kinetics for the decomposition of glucose and levoglucosan in high temperature water was examined. The temperature dependence of the reaction rate of the glucose decomposition was of the Arrhenius type. In contrast, the reaction rates for the decomposition of levoglucosan decreased with the increasing temperature at the constant pressure of 25 MPa. The yields of levoglucosan were examined in the temperature range from 200 to 410 °C and the pressure from 5 to 25 MPa. It was found that the yields of levoglucosan increased with the decreasing pressure. © 2009 Elsevier B.V. All rights reserved

Synthesis of 3-, 4-, 5-, 6-, 7-, 8-, 9-, 10-, 11-, and 12-armed star-shaped poly(styrene oxide) Ru(II) complexes by a click-to-chelate approach

This study describes the first convenient preparation of 3-, 4-, 5-, 6-, 7-, 8-, 9-, 10-, 11-, and 12-armed star-shaped poly(styrene oxide) (PSO) Ru(II) complexes using a click-to-chelate approach. This approach involves the combination of the click reaction and stepwise chelating reactions of Ru(II)(DMSO)(4)Cl-2 with macroligands, 2-(1-PSOn-1,2,3-triazol-4-yl)pyridine (PSOn-tapy) or 2-(1-PSOm-1,2,3-triazol-4-yl)-6-(1-PSOn-1,2,3-triazol-4-yl)pyridine (PSOm-bitapy-PSOn) (m, n = 1, 2, or 3). Click chemistry was used to prepare the PSOn-tapy and PSOm-bitapy-PSOn macroligands. More specifically, PSOn-tapy was prepared by reacting the azido-functionalized PSOn (PSOn-N-3) with excess 2-ethynylpridine. On the other hand, PSOm-bitapy-PSOn was obtained by the click reaction of excess PSOn-N-3 with 2,6-diethynylpridine to afford (PSOn)(2)-bitapy when m equals n, and by the stepwise click reactions of PSOm-N-3 and PSOn-N-3 with 2,6-diethynylpridine to produce PSOm-bitapy-PSOn when m is not equal to n. In order to obtain these polymer-substituted macroligands, PSOn-N-3 was initially synthesized by the living ring-opening polymerization (ROP) of styrene oxide (SO) using t-Bu-P-4 as a catalyst and the azido-functionalized mono- or multi-hydroxyl compounds, e.g., 6-azido-1-hexanol, 2-((6-azidohexyloxy)methyl)-2-methylpropane-1,3-diol (1) and 2-((6-azidohexyloxy)methyl)-2-(hydroxymethyl)propane-1,3-diol (2) as initiators

Synthesis, Inversion, and Chiral Discrimination of Helical Polymers Based on the Host-guest Complexation

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Chiroptical switching system based on the host–guest interaction between metal cations and poly(phenylacetylene)s bearing polycarbohydrate ionophore

International audienc

Response of shear stress to ac electric fields under steady shear flow in a droplet-dispersed phase

We have measured the response of shear stress to ac electric fields under steady shear flow in the droplet-dispersed phase of an immiscible polymer blend. A characteristic mode was found under steady shear flow, the relaxation frequency of which increased with increasing the shear rate. In the frequency dispersion, a scaling relation derived from dimensional analysis was confirmed to hold. The origin of the mode was investigated on the basis of the Maffettone-Minale (MM) model, in which the droplet shape is described by a second-rank tensor. The frequency dispersion of the response was also calculated using a modified MM model

Host-guest complexation-triggered chiroptical change of poly(phenylacetylene)s bearing binaphthocrown ether moieties on the main chain

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Thermoresponsive On−Off Switching of Chiroptical Property Induced in Poly(4‘-ethynylbenzo-15-crown-5)/α-Amino Acid System

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Synthesis and Helicity Induction of Poly(phenylacetylene) Derivatives Bearing a Crown Cavity on the Main Chain

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