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The direct introduction of a carboxylic group into an aromatic carboxylic acid has been considered difficult theoretically. Recently, the regioselective syntheses of terephthalic acid, 4,4′-biphenyldicarboxylic acid and 2,6-naphthalene-dicarboxylic acid have been achieved by the carboxylation of benzoic acid, 4-biphenylcarboxylic acid and 2-naphthalenecarboxylic acid, respectively, with carbon tetrachloride and copper powder in aqueous alkali, using β-cyclodextrin (β-CyD) as mediator under mild conditions. The one-pot syntheses of terephthalic acid, 4,4′-biphenyldicarboxylic acid and 2,6-naphthalene-dicarboxylic acid have been attained by the carboxylation of benzene, biphenyl and naphthalene, respectively, with carbon tetrachloride and copper powder in aqueous alkali, using β-CyD as mediator. The essential factor of the carboxylation by the use of β-CyD is the inclusion complex formations of β-CyD with aromatic hydrocarbon, β-CyD with aromatic monocarboxylate and β-CyD with carbon tetrachloride, respectively, in the reaction mixture. The conformations of CyD–aromatic monocarboxylate inclusion complexes in aqueous alkali have been determined by the nuclear magnetic resonance spectroscopy using 1H homonuclear Overhauser enhancement on the rotating frame. The high selectivity is ascribed to the conformation of the β-CyD–aromatic monocarboxylate inclusion complex. The reaction mechanism is discussed on the basis of inclusion complex formation.

The radical copolymerization of methyl methacrylate (MMA) and styrene (St) in the presence of various metal halides was conducted to achieve the advanced regulation of comonomer-sequence and stereosequence in the resulting copolymers. The alternation-regulating activities of various metal halides were determined quantitatively by the MMA content in the copolymer prepared under the specific conditions. Boron trichloride, aluminum tribromide and ethyl boron dichloride were found to have large alternation-regulating activities, yielding the strictly alternating MMA-St copolymers with high regulation of comonomer-sequence. The cotacticities of the -MMA-St- diad, the -St-MMA-St- triad and the­-MMA-St-MMA- triad in the alternating copolymer were determined by 1H- and 13C-NMR spectroscopies. The cotacticities depend on the species and the concentrations of the metal halides, and on the polymerization temperatures. The alternating MMA-St copolymer with the highest coheterotacticity has been prepared by using boron trichloride at − 95 °C. The mechanism of the stereosequence regulation is described in detail. Copyright © 2003 John Wiley & Sons, Ltd.

Poly(N-vinyl-2-pyrrolidone) (PVP) was chosen as a protecting polymer for its large protective value among homopolymers. Suspensions of palladium (Pd) nanoparticles were prepared by refluxing solutions of palladium(II) chloride and PVP in methanol. The mean diameter of Pd nanoparticles without adsorbed layer of PVP was controlled in the range 1.1–2.5 nm. The concentration of free PVP in the methanol suspension was determined by using aminoethylated poly(acrylamide) gel beads which adsorbed selectively the PVP-protected Pd nanoparticles. The amount of PVP adsorbed on Pd nanoparticles increased linearly with the 0.45 power of weight-averaged molecular weight (Mw) of PVP. The thickness of adsorbed layer of PVP was estimated from the sedimentation coefficient of the PVP-protected Pd nanoparticles. The adsorbed layer thickness increased linearly with the 0.55 power of Mw of PVP. The radius gyration of free PVP in methanol increased linearly also with the 0.55 power of Mw of PVP. The catalytic activity of the suspension of Pd nanoparticles was determined in the hydrogenation of 1,3-cyclooctadiene. The activity depended more effectively on the specific surface area of Pd nanoparticles than the adsorbed layer thickness. On the basis of these results, the conformation of protecting PVP molecule on the surface of Pd nanoparticles was proposed. Copyright © 2001 John Wiley & Sons, Ltd.

The selective synthesis of 2,6-naphthalenedicarboxylic acid from 2-naphthalenecarboxylic acid with carbon tetrachloride, copper powder, and aqueous alkali was achieved by using of β-cyclodextrin (β-CyD) as a catalyst at 60°C under nitrogen, producing 2,6-naphthalenedicarboxylic acid in 67 mol% yield with 84% selectivity. The one-pot preparation of 2,6-naphthalenedicarboxylic acid from naphthalene was attained at 84°C by using of β-CyD, producing 2,6-naphthalenedicarboxylic acid in 65 mol% yield with 79% selectivity. When α-CyD or γ-CyD was used instead of β-CyD on the carboxylation of 2-naphthalenecarboxylic acid and naphthalene, respectively, the reaction hardly proceeded. The conformation of β-CyD–2-naphthalenecarboxylate inclusion complex in aqueous alkaline solution was determined by the nuclear magnetic resonance spectroscopy using 1 H homonuclear Overhauser enhancement on the rotating frame. The 2-naphthalenecarboxylate anion was axially included in the cavity of β-CyD with an orientation which directed the 5-, 6-, and 7-positions of 2-naphthalenecarboxylate anion to the secondary hydroxyl side of β-CyD. It was concluded that the high selectivity of the carboxylation of 2-naphthalenecarboxylic acid was ascribed to the conformation of the β-CyD–2-naphthalenecarboxylate inclusion complex. The selective carboxylation of naphthalene was attributed to the formations of the β-CyD–naphthalene and β-CyD–2-naphthalenecarboxylate inclusion complexes.

Suspensions of palladium nanoparticles protected with poly( N -vinyl-2-pyrrolidone) (PVP) were prepared by refluxing the solution of palladium(II) chloride in methanol in the presence of PVP with various weight-average molecular weight ( M W = 6 000, 25 000, 175 000 and 574 000). The average diameter of palladium nanoparticles determined by transmission electron microscopy increased from 2.0 to 2.5 nm with increasing M W of PVP. The amount of PVP adsorbed on the palladium nanoparticles was determined by separation of palladium nanoparticle protected with PVP from dispersion medium using aminoethylated polyacrylamide gel. The amount of PVP adsorbed on palladium nanoparticles increased with increasing M W of PVP. The sedimentation coefficient of palladium nanoparticles was measured with ultracentrifugation for estimation of the thickness of adsorbed layer of PVP on palladium nanoparticles. The thickness of adsorbed layer of PVP on palladium nanoparticles increased from 1.9 to 7.8 nm with increasing M W of PVP. The higher molecular-weight fraction in PVP was more adsorbed on the palladium nanoparticles than the lower molecular-weight fraction. The catalytic activity of the suspension of palladium nanoparticles protected with PVP was determined in the hydrogenation of 1,3-cyclooctadiene at 30°C under 1 atm of hydrogen. The influence of adsorbed layer on the catalytic activity was investigated.

A copper(I) chloride-N,N,N′,N′-tetramethyl-1,2-ethanediamine complex supported on silica gel was prepared by mixing porous silica gel with an acetonitrile solution containing the complex composed of copper(I) chloride (CuCl) and N,N,N′,N′-tetramethyl-1,2-ethanediamine (M4en) under nitrogen, followed by removal of liquid phase under reduced pressure. The resulting silica gel, 6.0 g, supported 4.92 mmol of 1 : 1 CuCl-M4en complex. It rapidly adsorbed carbon monoxide (CO) at 30°C under 1.0 atm of CO, and the equilibrium amount of adsorbed CO was 4.30 mmol (87 mol% against supported complex). The adsorbed CO was rapidly desorbed by maintaining it at 120°C under 1.0 atm or at 30°C under 0.1 mmHg. The adsorption-desorption cycle was repeated without any deterioration. The equilibrium amount of adsorbed CO (4.30 mmol) was 11.8 times that of adsorbed carbon dioxide (0.37 mmol), and 40.9 times that of adsorbed methane (0.11 mmol) at 30°C under 1.0 atm. The reversible and selective adsorption of CO was attributed to formation of 1: 1: 1 CuCl-M4en-CO complex. When the adsorbent contacted with oxygen, the CO-adsorbing ability decreased. The adsorbing ability was completely recovered by maintaining the adsorbent at 120°C under 1.0 atm of CO for 3 h.

Dependence of oxygen deficiency of BaBiO 3-δ on temperature and oxygen partial pressure at a state of equilibrium was investigated by thermogravimetry. Two phases, one with 0.00 ≤ δ < 0.03 (phase I) and the other with 0.43 < δ ≤ 0.50 (phase II). and the first order phase transition between them was observed below 700°C, Besides the two phases, another phase (phase III) with 0.10 < δ < 0.20, which could be regarded as stable at high temperatures, appeared at 750°C. It was observed that the phase transitions of I⇔III and II⇔III are also first order. By increasing the temperature up to 800°C, the δ range of phase III increased to 0.06

The introduction of two carboxyl groups into the 4- and 4′-positions of biphenyl has been achieved by the one-step reaction of biphenyl, carbon tetrachloride and copper powder in aqueous alkali by the use of β-cyclodextrin as catalyst at 78°C under nitrogen of atmospheric pressure, producing 4,4′-biphenyidicarboxylic acid in 61 mol% yield with 85% selectivity.

ポリ (N-ビニル-2-ピロリドン) (PVP) に保護されたパラジウムナノ粒子 (PVP-Pdナノ粒子) をメタノール分散液中からトリメチルアンモニウム基を有するポリスチレンゲル (PSt-TA) に吸着させることを試みた. PVP-Pdナノ粒子は, ゲル型のPSt-TAに吸着されず, 多孔型のPSt-TA (PSt-HPA) (平均細孔径140nm) に吸着された. PVPの平均分子量 (Mw: 6000, 25000, 175000, および574000) が増加するにつれ, PVP-Pdナノ粒子のPSt-HPAへの吸着量は減少した. 超遠心法によりPVPの吸着層を含めたPVP-Pdナノ粒子の粒径を測定した結果, Mwが増加するにつれ, この粒径は増加した. PSt-HPAに吸着されたPVP-Pdナノ粒子は, 1, 3-シクロオクタジエンの水素化反応の触媒として. 10回以上の繰り返し使用においても最初の活性および選択性を保持した.

炭素繊維の繊維束内に, ピッチコークス, メソフェーズピッチ, および鱗片状コークスなどのマトリックス粉を包含させ, ポリプロピレンで被覆することによりプリフォームドヤーンを作製した. このプリフォームドヤーンを金属製の芯棒にらせん状に巻いてホットプレス成形することにより, 炭素繊維強化炭素製コイルスプリングの作製を行った. 炭素繊維に紡績糸を用いたプリフォームドヤーンを使用して作製したスプリングは, フィラメント糸を用いたものと比較して高いばね定数を示した. 紡績糸の体積含有率を35～75 vol%で変化させると, ばね定数は含有率が60 vol%のときに最も高い値を示した. マトリックス組成を変化させると, メソフェーズピッチが60 wt%, ピッチコークスが34.6 wt%, 燐片状コークスが6.4 wt%のときばね定数は最も高い値を示した. 一方, 繊維配向が二次元の炭素繊維強化炭素製ブロックから削り出して作製したコイルスプリングは, 非常に低いばね定数しか示さなかった.

The selective synthesis of terephthalic acid from benzoic acid with carbon tetrachloride, copper powder and aqueous alkali was achieved by the use of β-cyclodextrin (β-CyD) as a catalyst at 60°C under nitrogen of atmospheric pressure, producing terephthalic acid in 74 mol% yield with 100% selectivity. The carboxylation of 4-biphenylcarboxylic acid with carbon tetrachloride, copper powder and aqueous alkali using β-CyD under similar conditions produced 4,4′-biphenyldicarboxylic acid in 71 mol% with 100% selectivity. 2,6-Naphthalenedicarboxylic acid was synthesized by the carboxylation using β-CyD under similar conditions in 67 mol% yield with 84% selectivity. When α-CyD or γ-CyD was used instead of β-CyD, the reaction hardly proceeded. The conformations of CyD–aromatic monocarboxylate inclusion complexes in aqueous alkaline solution were determined by the nuclear magnetic resonance spectroscopy using 1H homonuclear Overhauser enhancement on the rotating frame. The essential factor of the carboxylation was the inclusion complex formations of β-CyD with aromatic monocarboxylate and β-CyD with carbon tetrachloride in the reaction mixture. The high selectivity was ascribed to the conformation of the β-CyD–aromatic monocarboxylate inclusion complex. © 1997 John Wiley & Sons, Ltd.

We study transport coefficients of Al 0.3 Ga 0.7 As GaAs heterostructure Hall bars with two Schottky cross gates placed separately leaving a 100 μm-long gate-free region. When the gate-free region is in a quantum Hall effect state at low temperatures, the electron states in the separated gated regions strongly interfere with each other, being mediated by the edge states in the gate-free region. The experimental results indicate that the phase coherence of edge states extends over a distance far larger than 200 μm at 25 mK.

Crystal symmetry and lattice constants of BaPb1−xBixO3 were analyzed by X-ray diffraction using synchrotron radiation as a light source. Measurements with high resolution could be carried out and crystal system of BaPb1−xBixO3 could be determined clearly. Monoclinic and orthorhombic symmetry were observed in the x range 0.5 ≦ x ≦ 1.0 and 0.0 ≦ x ≦ 0.5, respectively, showing agreement with the electrical conduction behavior and optical reflection property of BaPb1−xBixO3.

The selective synthesis of terephthalic acid from benzoic acid with carbon tetrachloride, copper powder, and aqueous alkali was achieved by the use of β-cyclodextrin (β-CyD) as a mediator at 60°C under nitrogen of atmospheric pressure, producing terephthalic acid in 74 mol% yield with 100% selectivity. When α-CyD or γ-CyD was used instead of β-CyD, the reaction hardly proceeded. The addition of p-benzoquinone to the reaction mixture decreased the yield of terephthalic acid remarkably. An oxygen atmosphere also suppressed the reaction appreciably. Thus, the active species formed from carbon tetrachloride and copper powder in the reaction mixture is proposed to be trichloromethyl radical. The conformations of CyD-benzoate inclusion complexes in aqueous alkaline solution were determined by the nuclear magnetic resonance spectroscopy using 1H homonuclear Overhauser enhancement on the rotating frame. The benzoate anion was axially included in the cavity of β-CyD with orientation such that the carboxylate group was at the primary hydroxyl side of β-CyD. The essential factor of the carboxylation by the use of β-CyD was the inclusion complex formation of β-CyD with benzoate anion and β-CyD with carbon tetrachloride in the reaction mixture. The very high selectivity was ascribed to the conformation of the β-CyD-benzoate inclusion complex.

Stable dispersions of colloidal metals in hydrocarbons have been prepared by a novel phase-transfer method. The metals were gold, silver, palladium and ruthenium; the hydrocarbons were n-hexane, cyclohexane and benzene. The phase transfer of colloidal metal particles from an aqueous phase to a hydrocarbon phase was achieved by adding salt to the emulsion of hydrocarbon in the aqueous suspension of metal with sodium oleate. The salts were sodium chloride, magnesium chloride, sodium sulfate, etc. The size distributions of the metal particles in the resulting hydrocarbon suspensions were almost the same as that of the original aqueous suspension. The dispersions of colloidal metals in hydrocarbons were stable for a long period of time without the addition of hydrocarbon-soluble stabilizer. The critical phase-transfer concentrations of various salts were determined. The phase-transfer powers of cations were larger than those of anions. Those of divalent and trivalent cations were exceedingly larger than that of the monovalent cation. The concentration of colloidal metal dispersed in hydrocarbon was achieved by using the phase-transfer method.

The conformations of β-cyclodextrin (β-CyD)-benzoate and β-CyD-biphenylcarboxylate inclusion complexes have been determined by 1 H ROESY NMR spectrometry.

The one-step synthesis of 2,6-naphthalenedicarboxylic acid from naphthalene with carbon tetrachloride, copper powder and aqueous alkali has been achieved under mild conditions by the use of β-cyclodextrin as catalyst, producing 2,6-naphthalenedicarboxylic acid in 65 mol-% yield with 79% selectivity.

The selective carboxylation of 4-biphenylcarboxylic acid with carbon tetrachloride in aqueous alkali to obtain 4,4′-biphenyldicarboxylic acid was achieved by the use of s-cyclodextrin and copper powder II under mild conditions.

Terephthalic acid was synthesized by the carboxylation of benzoic acid with CCl 4 in aqueous NaOH solution in the presence of cyclodextrin (CyD) and copper powder as catalyst. By the use of β-CyD at the initial molar ratio to benzoic acid of 0.5, the carboxylation at 60°C for 7 hours produced terephthalic acid in 75 mol% yield with 87% selectivity. The selective synthesis of 4,4'-biphenyldicarboxylic acid in 70 mol% yield was achieved by the carboxylation of 4-biphenylcarboxylic acid with CCl 4 in the presence of β-Cyd under similar conditions

Stable dispersions of colloidal gold in n-hexane and cyclohexane have been prepared by transfer of colloidal gold particles from an aqueous phase to a n-hexane phase and to a cyclohexane phase, respectively. The phase transfer of gold particles occurred on addition of magnesium chloride to the emulsion of hexane in the aqueous suspension of gold with sodium oleate. The size distributions of the gold particles in the resulting colloidal gold in hexane suspensions were almost the same as that (mean diameter 14 nm, standard deviation 1.5 nm) of the original aqueous suspension of gold. The critical phase-transfer concentrations of various salts were determined. The phase-transfer powers of cations were larger than those of unions. Those of divalent and trivalent cations were exceedingly larger than that of the monovalent cation.

The geometrical and electronic structures of the binary radical complexes of 2-methoxycarbonyl propyl radical with boron trichloride and with boron trifluoride were determined by using an ab initio molecular orbital method. The 2-methoxycarbonyl propyl radical complex was a model of the growing radical end in the copolymerization of methyl methacrylate in the presence of boron halides. The most stable structure of the binary radical complex composed of 2-methoxycarbonyl propyl radical with boron trichloride was a twisted form in which the dihedral angle between the vinyl group and the ester group was 32°, while that of the binary radical complex composed of methyl methacrylate radical with boron trifluoride was a planar form as the free radical. The frontier orbital energy of 2-methoxycarbonyl propyl radical was lowered by 0.06 au by the coordination of boron trichloride, while that was lowered only by 0.02 au by the coordination of boron trifluoride. The polymerization mechanism was elucidated on the basis of these predictions. © 1993 John Wiley & Sons, Inc.

Benzoic acid is found to undergo carboxylation by warming with carbon tetrachloride in aqueous alkali in the presence of copper powder with β-cyclodextrin as catalyst. The reaction under mild conditions gives terephthalic acid in good yield with high selectivity.

Colloidal silver particles dispersed in water are found to be transferred into a nonaqueous liquid by the addition of sodium chloride to an emulsion of the nonaqueous liquid in the aqueous dispersion of colloidal silver with sodium oleate. The colloidal dispersions of silver in cyclohexane, n-hexane and benzene are prepared by phase transfer using sodium oleate and sodium chloride.

Benzoic acid is found to undergo carboxylation by warming with carbon tetrachloride in aqueous alkali in the presence of copper powder with β-cyclodextrin as catalyst. The reaction under mild conditions gives terephthalic acid in good yield with high selectivity.

Four anionic surfactants having two polyfluoroalkyl chains in a molecule, sodium salt of bis(1H,1H,2H,2H-heptadecafluorodecyl) 2-sulfosuccinate, CF3(CF2)7(CH2)2OCOCH2CH(SO3Na)COO(CH2)2(CF2)7CF3, sodium salt of bis(1H,1H,9H-hexadecafruorononyl) 2-sulfosuccinate, H(CF2)8CH2OCOCH2CH(SO3Na)COOCH2(CF2)8H, sodium salt of bis(1H,1H,7H-dodecafluoroheptyl) 2-sulfosuccinate, H(CF2)6CH2OCOCH2CH(SO3Na)COOCH2(CF2)6H and sodium salt of bis(1H,1H,5H-octafluoropentyl) 2-sulfosuccinate, H(CF2)4CH2OCOCH2CH(SO3Na)COOCH2(CF2)4H, were prepared from maleic anhydride, the corresponding alcohols having a polyfluoroalkyl chain and sodium hydrogensulfite. The flocculation and redispersion abilities of these surfactants against dispersed magnetite particles in water have been examined in comparison with other four anionic surfactants having a single polyfluoroalkyl chain in a molecule; sodium pentadecafluorooctanoate, CF3(CF2)6COONa, sodium 9H-hexadecafluorononanoate, H(CF2)8COONa, sodium 7H-dodecafluoroheptanoate, H(CF2)6COONa, an...

Four new silicon compounds, dimethoxysilanediyl bis(5H-octafluoropentanoate), (CH3O)2Si[OCO(CF2)4H]2, dimethoxysilanediyl bis(7H-dodecafluoroheptanoate), (CH3O)2Si[OCO(CF2)6H]2, dimethoxysilanediyl bis(9H-hexadecafluorononanoate), (CH3O)2Si[OCO(CF2)8H]2, and dimethoxysilanediyl bis(pentadecafluorooctanoate), (CH3O)2Si[OCO(CF2)6CF3]2, were prepared by the reaction of dichlorodimethoxysilane with sodium salts of fluoro-substituted carboxylic acid. The 1H NMR, 13C NMR, and 19F NMR and IR spectral data of these silicon compounds were obtained. In the course of a study of the stability of the silicon compounds against hydrolysis by using 1H NMR spectral measurements, it was found that the ease of hydrolysis of the SiOCOR and the SiOCH3moieties was exactly same.

The stereo and the electronic structures of methyl methacrylate and the binary molecular complex composed of methyl methacrylate and boron trichloride are determined by quantum chemical calculations based on ab initio molecular orbital methods with the STO-3G basis set. The Stable structures of methyl methacrylate in the free state are a transoid from and a cisoid form. The transoid form is slightly (0.5 kcal/mol) more stable than the cisoid form. The total energy change accompanying binary molecular complex formation is calculated to be −43 kcal/mol. The most stable structure of the binary molecular complex composed of methyl methacrylate and boron trichloride is a twisted form in which the dihedral angle between the vinyl group and the ester group is 19.7°. A large amount of electron transfer from methyl methacrylate to boron trichloride is calculated to occur on binary molecular complex formation. Mulliken's population analysis shows the electron transfer to be the origin of the twist of the binary molecular complex. The energy level of the lowest unoccupied molecular orbital is substantially lowered by the coordination of boron trichloride.

Titanium butoxide tris(5H-octafluoropentanoate), Ti(OnC4H9)[OCO(CF2)4H]3, titanium butoxide tris(7H-undecafluoroheptanoate), Ti(OnC4H9)[OCO(CF2)6H]3, titanium butoxide tris(9H-hexadecafluorononanoate), Ti(OnC4H9)[OCO(CF2)8H]3, and titanium butoxide tris(perfluorooctanoate), Ti(OnC4H9)[OCO(CF2)6CF3]3, were prepared by the reaction of titanium butoxide trichloride with sodium fluoro-substituted acylates in 1,1,2-trichloro-1,2,2-trifluoroethane. These compounds were characterized on the basis of elemental analysis as well as their IR, 1H NMR, 13C NMR, and 19F NMR spectra. In the compounds produced, a Ti–OCO bond was stable in water, although a Ti–OR bond was only moderately stable in water. A surface modification against calcium carbonate was attempted by using these products. From measurements of the contact angles θ(°) of water and toluene against a modified calcium carbonate surface, titanium butoxide tris(perfluorooctanoate) was found to be an effective substance for a new-type coupling agent, which incr...

Coisotactic parameters of two steps in a propagating process, one from styrene (St) unit to methyl methacrylate (MMA) unit and the other from MMA unit to St unit, were experimentally determined in ...

The direct introduction of a carboxylic group into an aromatic carboxylic acid has been considered difficult theoretically. Recently, the regioselective syntheses of terephthalic acid, 4,4′-biphenyldicarboxylic acid and 2,6-naphthalene-dicarboxylic acid have been achieved by the carboxylation of benzoic acid, 4-biphenylcarboxylic acid and 2-naphthalenecarboxylic acid, respectively, with carbon tetrachloride and copper powder in aqueous alkali, using β-cyclodextrin (β-CyD) as mediator under mild conditions. The one-pot syntheses of terephthalic acid, 4,4′-biphenyldicarboxylic acid and 2,6-naphthalene-dicarboxylic acid have been attained by the carboxylation of benzene, biphenyl and naphthalene, respectively, with carbon tetrachloride and copper powder in aqueous alkali, using β-CyD as mediator. The essential factor of the carboxylation by the use of β-CyD is the inclusion complex formations of β-CyD with aromatic hydrocarbon, β-CyD with aromatic monocarboxylate and β-CyD with carbon tetrachloride, respectively, in the reaction mixture. The conformations of CyD–aromatic monocarboxylate inclusion complexes in aqueous alkali have been determined by the nuclear magnetic resonance spectroscopy using 1H homonuclear Overhauser enhancement on the rotating frame. The high selectivity is ascribed to the conformation of the β-CyD–aromatic monocarboxylate inclusion complex. The reaction mechanism is discussed on the basis of inclusion complex formation.

This paper reports on an aqueous dispersion of the resin-iron(II) complex prepared from FeSO{sub 4} and chelate resin containing iminodiacetic acid moieties. The dispersion can simultaneously adsorb nitrogen monoxide and sulfur dioxide from a dilute mixed gas used as a model of a flue gas. The adsorbent dispersion was slightly deactivated by oxygen. The rate of deactivation of the dispersion, however, was much less than that of an aqueous solution of the corresponding monomeric model due to the slow diffusion of oxygen into the resin in the former case. Even after deactivation, the chelate resin can be easily recovered from the deactivated aqueous dispersions by separation by filtration, washing with a hydrochloric acid solution, and neutralization with a sodium hydroxide solution. The recovered resin can be reused as a starting material for the preparation of the fresh adsorbent dispersion by mixing with an aqueous FeSO{sub 4} solution.

Macromolecule-copper(I) chloride complexes have been prepared for the separation of carbon monoxide and ethylene from gas mixtures with hydrogen, nitrogen, carbon dioxide, methane, and water. A toluene solution of a polystyrene-aluminum copper(I) chloride complex can separate carbon monoxide selectively and retains this function even on contact with gas containing water. Strong charge-transfer absorption bands have been found in the 380-500 nm region for the toluene solution of polystyrene-aluminum copper(I) chloride complex. A solution of 1, 3-diphenylpropane-aluminum copper(I) chloride complex also exhibits similar absorption bands. A continuous variation plot using the chemical shift change in 13C-NMR shows a 1:1 interaction between 1,3-diphenylpropane and aluminum copper(I) chloride. These results suggest a two-way interaction between the adjacent phenyl groups of polystyrene and aluminum copper(I) chloride. A resin bead of crosslinked polystyrene-aluminum copper(I) chloride complex has been ...

The new compounds, tetrakis(1H, 1H, 3H-perfluoropropyl) silicate, Si(OCH2CF2CF2H)4, tetrakis(1H, 1H, 5H-perfluoropentyl) silicate, Si[OCH2(CF2CF2)2H]4, tetrakis(1H, 1H, 7H-perfluoroheptyl) silicate, Si[OCH2(CF2CF2)3H]4 and tetrakis-(1H, 1H, 9H-perfluorononyl) silicate, Si[OCH2(CF2CF2)4H]4, were prepared by the reaction of silicon tetrachloride with fluoro-substituted alcohols in the presence of ammonia. The 1H, 13C, 19F NMR and IR spectral data of these silicates were obtained.

Colloidal copper dispersions are prepared by reducing copper(II) ions in water with sodium tetrahydroborate or hydrazine in the presence of various protective polymers. The polymers are poly(N-vinyl-2-pyrrolidone), poly(vinyl alcohol), poly(methyl vinyl ether), poly(potassium vinyl sulfate), dextrin, amylopectin, methylamylopectin, methylcellulose, ethylcellulose, and (2-hydroxyethyl)cellulose. The dispersions are black, reddish dark brown, or reddish brown homogeneous solutions, and are stable under nitrogen at room temperature for more than three months. Electron diffraction experiments indicate that copper atoms in the colloidal particles are arranged in an ordered way, which is almost identical with that in a crystal of bulk copper metal. At the charged molar ratio 40 of the monomeric residue of the protective polymer to copper(II) ion, the average diameters of the copper particles, prepared by use of sodium tetrahydroborate, range from 50 to 150 A, depending on the polymer used. With the use of poly(...

The 13C NMR spectra of poly(methyl acrylate-co-styrene) are interpreted by a theoretical procedure which consists of conformational analysis of the random copolymer chain and shielding calculation. The conformational probabilities of the diad sequences constituting poly(methyl acrylate-co-styrene) are calculated by a matrix method which is conducted by the statistical mechanics of polymer chains. All the elements of the matrices are determined by the force field method. As significant shielding factors for 13C nuclei, paramagnetic, diamagnetic, and anisotropic terms are taken into account. The calculation is used to assign the observed split peaks for the carbonyl carbon and methoxyl carbon in the copolymer. A good agreement between calculation and observation of the peak splittings due to the distribution of the monomer sequence as well as that of the stereo sequence was obtained by considering the feasibility of rotational isomerization at the side chain ester group in two successive MA units.

Colloidal dispersions of noble metals in synthetic polymers are prepared by reduction with alcohol. Reflux of a solution of rhodium(III) chloride and poly(vinyl alcohol) (PVA) in a methanol-water mixed solvent under argon or air for 4 hr gives a homogeneous solution of colloidal dispersion of rhodium (Rh-PVA-MeOH/H2O). The particle size of metallic rhodium is distributed n a narrow range of 30-70 A, and the average diameter is 40 A. The formation of colloidal rhodium proceeds through three steps: coordination of poly(vinyl alcohol) to rhodium(III) ion, reduction with methanol to form small particles (8 A in diameter), and growth of the small particle to large particle (40 A in diameter). Polyvinylpyrrolidone (PVP) and poly(methyl vinyl ether) (PMVE) can be used in place of poly(vinyl alcohol) and result in colloidal dispersions, respectively, similar to Rh-PVA-MeOH/H2O. Colloidal dispersions in nonaqueous solvent can be prepared by using ethanol instead of methanol-water (Rh-PVP-EtOH) and by usin...

A polymer–palladium complex prepared from palladium(II) chloride and styrene-divinylbenzene copolymer with iminodiacetic acid groups is found to catalyze the selective hydrogenation of conjugated diolefins to monoolefins at 30°C under an atmospheric hydrogen pressure.

The equilibrium constants for the complex formation between stannic chloride and methyl methacrylate were determined in n-hexane–toluene solution at 0, −20, and −30°C by using the absorption band at 350 nm. Continuous variation plots at −20°C in n-hexane based on the 1H-chemical shifts definitely show a 1:1 interaction between the coordinated methyl methacrylate and styrene or toluene. The magnitudes of the shifts for the four groups of protons in methyl methacrylate are found to be in a specific ratio in common with the 1:2 complex–styrene or -toluene system. The equilibrium constants for the ternary molecular complex formation between the 1:2 complex and styrene or toluene were determined in n-hexane in the temperature range −50 to +20°C by use of the chemical shifts. The concentrations of the complex species in the alternating copolymerization solutions were estimated by use of the equilibrium constants. There is a linear relationship between the enthalpy and the entropy changes for the ternary molecular complex formation, which is governed by the enthalpy factor. The specificity of the interactions indicates a specific time-averaged orientation of benzene ring to the coordinated methyl methacrylate. The effects of the coordination of methyl methacrylate to stannic chloride were discussed on the basis of results of 13C-NMR spectroscopy.

A polymer–rhodium complex prepared from rhodium(III) chloride and styrene-divinylbenzene copolymer with iminodiacetic acid groups is found to catalyze the heterogeneous hydrogenation of alkenes in polar solvents at 30°C under an atmospheric hydrogen pressure. The polymer complex hydrogenates selectively the ethylenic double bonds in the alkenes with carbonyl and aromatic groups. The rates of hydrogenation of alkenes by the polymer complex are found to be markedly affected by the steric hindrance of the substrates.

NMR chemical shifts of the methoxyl and α-methyl protons in the alternating methyl methacrylate-styrene copolymer are calculated by taking into account the contributions of the diamagnetic shielding and the magnetic anisotropy effect of the benzene rings in styrene units. The conformational probabilities of the copolymer chain are calculated according to Flory's matrix method. It is deduced from the calculation that NMR should occur at higher field for the methoxyl and at lower field for the α-methyl protons of the methyl methacrylate unit in meso configuration with an adjacent styrene unit (regarding the methoxycarbonyl and phenyl groups) than for the corresponding protons in the unit of racemic configuration. Further, the differences between the chemical shifts for these protons in meso and racemic dyads are nearly equivalent to the differences in chemical shifts between two adjacent peaks of the observed triplet spectra. This result indicates that the spectral assignment based on a theoretical calculation is quite consistent with the one made by a conventional simulation method: from the lower magnetic field, peaks of cosyndiotactic, coheterotactic, and coisotactic triads appear in this order for the methoxyl protons and in the opposite order for the α-methyl protons. Magnetic anisotropy effect contributes to these tacticity-dependent chemical shifts to a far greater extent than diamagnetic shielding. The variation of the chemical shifts due to measuring temperature, probability of isotactic addition, and interactions between groups more than five bonds apart is also discussed.