Hideyuki Tagaya

New Layered Double Hydroxide, Zn–Ti LDH : Preparation and Intercalation Reactions

The layered double hydroxide (LDH) well known for its abilityto intercalate anionic compounds has been prepared conventionallyonly with bivalent and trivalent cations. In this study, Zn–Ti LDH consisting of bivalent and tetravalent cations was prepared, andreacted with organic monocarboxylic, dicarboxylic and aromatic acidsat high or room temperature. XRD patterns of the prepared LDH(Zn–Ti-CO3) showed that interlayer spacing of the LDH was 0.67 nm. The value was small compared to the usual LDH (Zn–Al–CO3)of 0.76 nm in the case of carbonate anion as the guest. Also, DTA,TG and DTG analysis indicated that the electrostatic force betweenthe layers and carbonate anions increased where the carbonate anionsin Zn–Ti LDH decomposed at 255 °C while those inZn–Al–CO3 decomposed at 230–240 °C.

Photoisomerization of indolinespirobenzopyran in anionic clay matrices of layered double hydroxides

Sulfonated indolinespirobenzopyran (SP–SO3–) was intercalated into the Mg/Al or Zn/Al layered double hydroxides (LDHs) in the presence of toluene-p-sulfonic acid (PTS). The new intercalates exhibited reversible photoisomerization between SP–SO3– and merocyanine (MC). The presence of PTS was critical for the reversible photoisomerization. MC was very stable and the rate constant of decolorization was <9 × 10–7S–1. SP interacted with non-polar portions between the layers although MC interacted with the polar interior surface of the LDH.

Intercalation of colored organic anions into insulator host lattices of layered double hydroxides

Abstract Colored organic anions such as tetra (4-carboxyphenyl)porphyrin (TPP-C), tetra(4-sulfonatophenyl)porphyrin (TPP-S), tetracarboxyphthalocyaninato cobalt (TPC-C) and others were intercalated into the Mg Al and Zn Al layered double hydroxides (LDHs). After the intercalation of organic anions, interlayer spacing of the LDHs increased to 7.8–30.7 A depending on the amounts of intercalated anions and the sizes of these anions. The amounts of intercalated organic anions reached 48–100% of the exchange capacity of the Zn Al LDH. Absorption maxima of TPP-C and TPP-S intercalates were from 439 to 445 nm and longer than 414 to 420 nm, respectively, of TPP-C and TPP-S alone in solvents.

Disproportionation of diarylmethanol derivatives by using supercritical water

Non-catalytic disproportionation of diarylmethanol derivatives was found to proceed efficiently in supercritical water. This method was also applied to various diarylmethylamine derivatives to give the disproportionation products in good yields.

Effect of diaminotoluene on the decomposition of polyurethane foam waste in superheated water

Post-use polyurethane (PU) foam was degraded in superheated water at 423 to 623 K. The yield of diaminotoluene (TDA), one of the products, reached near 90%. The hydrolysis conditions (time and temperature) were important and the perfect liquid products could be obtained under the economic conditions at 523 K for 30 min. TDA was added to the reaction to investigate the effect on the decomposition of PU foam waste. However, in our conditions, basic additives only slightly improved the yield of TDA.

Synthesis of an amylose–polymer inclusion complex by enzymatic polymerization of glucose 1-phosphate catalyzed by phosphorylase enzyme in the presence of polyTHF: a new method for synthesis of polymer–polymer inclusion complexes

The enzymatic polymerization of α-D-glucose 1-phosphate (Glc-1-P) with phosphorylase in the presence of polytetrahydrofuran (polyTHF) leads to an amylose–polyTHF (polymer–polymer) inclusion complex; the present reaction system provides a new method for the preparation of polymer–polymer inclusion complexes.

Ring‐Opening Polymerization of Ethylene Carbonate Catalyzed with Ionic Liquids: Imidazolium Chloroaluminate and Chlorostannate Melts

Ring-opening polymerization of ethylene carbonate in the presence of ionic liquids, 1-butyl-3-methylimidazolium chloroaluminate melt and 1-butyl-3-methylimidazolium chlorostannate melt, has been investigated. Polymerization takes place accompanied with decarboxylation even at temperatures below 100°C under the reaction conditions selected to give poly(ethylene ether-carbonate)s.

Synthesis of kojic acid derivatives containing phenolic hydroxy groups

Abstract Two kojic acid derivatives (2a and 2b) containing phenolic hydroxy groups were synthesized. The preparation was carried out by the reaction of a kojic acid derivative (3) having a chloromethyl group with phenol derivatives (4 and 7), followed by the subsequent deprotection steps. The first reaction proceeded smoothly in the presence of potassium carbonate in DMF at room temperature. Then, the appropriate deprotection reactions gave the desired compounds 2a and 2b. The structures of 2a and 2b were confirmed by the 1H NMR spectra.

Synthesis of Hyperbranched Aminopolysaccharides

Sugar dihydroozaxole monomers with two free hydroxyl groups undergo acid-catalyzed polymerization to hyperbranched aminopolysaccharides [Eq. (a)]. Their molecular weights were determined by the light-scattering method to be between 2.3×105 and 7.6×105 . The degree of branching determined by 1 H NMR spectroscopy after reaction with [iPr2 Si(Cl)]2 O is close to the ideal value. Ts=MeC6 H4 SO2 , CSA=10-camphorsulfonic acid.

Intercalation of organic compounds in the layered host lattice MoO3

Organic compounds such as alkylpyridines, methyl viologen and azo compounds have been intercalated into MoO3layers by ion exchange in which MoO3x–(Na+)x reacted with the organic compounds. Indolinespirobenzopyran (SP) was intercalated by a multi-step method in which amine was intercalated in the first step, and by the co-intercalation of amine and SP the MoO3 layer expanded to 24–28 A depending upon the kind of amine used in the first step. In the layers, SP existed as its isomerized coloured species, merocyanine (MC). Reduction of Mo by chemical reduction and intercalation of amines and SP was confirmed by X-ray photoelectron spectroscopy.