Sakuji Ikeda

Spectroscopic studies on doped polyacetylene and β-carotene

In order to elucidate the structural details of doped polyacetylene (a highly conducting organic polymer), the optical absorption, Raman, and infrared spectra of not only trans‐(CH)x doped with iodine, AsF5, and SO3 but also β‐carotene doped with iodine and SO3 were studied. The infrared spectra of two kinds of isotopically substituted polyacetylenes (CD)x and (13CH)x doped with iodine were also observed. Analysis of the experimental results shows that upon doping each of the four vibrational branches (ν1–ν4) in the 1600–900 cm−1 region of a polyene chain splits into two groups, namely, the higher frequency group and the lower frequency one. The former group consists of the ’’gerade’’ vibrations of polyene parts which are not directly attacked by dopants but are perturbed along the chain, whereas the latter is made up of the ’’ungerade’’ vibrations of the positively charged polyene part with the doped site at its center. The Raman bands in the higher‐frequency group of ν1 (mainly the C=C stretching mode) ...

Preparation and properties of aryl(dipyridyl)nickel halide complexes

Abstract Several aryl(dipyridyl)nickel halide complexes of the composition R(dipyridyl)NiX (R = phenyl, o -tolyl, m -tolyl, p -tolyl and o -chlorophenyl, X = I, Br and Cl) have been prepared from diethyl(dipyridyl)nickel and aryl halides. The complexes were characterized by elemental analyses, NMR spectroscopy and chemical reactions. The complexes exhibited no catalytic activity for the polymerization of vinyl monomers such as acrylonitrile, methacrylonitrile and methyl methacrylate. However, in combination with Lewis acids such as AlEtCl 2 and AlEt 2 Cl, the aryl(dipyridyl)nickel halide complexes show higher catalytic activity in propylene dimerization, compared to dipyridylnickel dichloride and the parent diethyl(dipyridyl)nickel. The results of the propylene dimerization experiments all favor the view that the aryl group in the nickel complex is retained in the active species in spite of the large excess of Lewis acid present in the system.

Preparation and properties of alkylchromium dichloride complexes

Abstract A series of monoalkylchromium complexes, RCrCl 2 (THF) 3 where R = methyl, ethyl, n-propyl and isobutyl and THF = tetrahydrofuran, have been prepared by reactions of chromium trichloride with organoaluminum compounds. Elemental analyses, magnetic susceptibility measurement, electronic and IR spectroscopy and chemical properties of the complexes support the above formulation. The thermal stabilities of the complexes decrease in the order CH 3 > C 2 H 5 > C 3 H 9 > C 4 H 9 . The effects of the alkyl groups on the rates of decomposition, and on the electronic and IR spectra of the alkylchromium complexes are discussed. The thermal decompositions of the alkylchromium complexes release alkanes, alkenes, dimeric alkanes and THF with more alkane than alkene always being formed. No evidence was obtained for chromium hydride formation in the pyrolysis. Stable pyridine-coordinated alkylchromium complexes were prepared by ligand exchange reactions of RCrCl 2 (THF) 3 with pyridine. The alkylchromium complexes catalyse ethylene polymerization under mild conditions.

Hydrogenation of ethylene over some intermetallic compounds

Th kinetics and mechanism of ethylene hydrogenation were determined on LaNi/sub 5/, PrCo/sub 5/, LaCo/sub 5/, CeCo/sub 5/, SmCo/sub 5/, and on their hydrides prepared at 450/sup 0/C and 100 atm hydrogen pressure. The tests were conducted in a recycle reactor at -85/sup 0/ to -46/sup 0/C, 22-158 mm Hg ethylene pressure and 0-190 mm Hg hydrogen pressure. The reactions of ethylene with hydride hydrogen were more rapid than the reactions of ethylene with hydrogen catalyzed by the metal alloys. The rates of ethylene formation and the apparent activation energies of the reactions of ethylene with the metal hydrides corresponded to the hydrogen desorption rates and the activation energies of desorption of the hydride hydrogen, which suggested that hydrogen migration in the bulk is the rate-determining step.

The Mechanism of Reaction of Sulfur Compounds with Steel Surface During Boundary Lubrication, Using S35 as a Tracer

The mechanism of the action of sulfur compounds during boundary lubrication has been studied by using S35 as a tracer. A NACA type friction machine was used to study the chemical reaction between elementary sulfur or sulfur compounds and metals. All additives were added to cetane which was used as a lubricating oil. It has been found that it is possible to study kinetically the formation of the iron sulfide and the rate of the wear of its film on the friction surface. Some good analytical results have been obtained. The rate of wear of iron sulfide film for benzyl disulfide is lower than that for the elementary sulfur, because the former may adsorb effectively to the worn surface. The iron sulfide film formed on the friction surface seems to absorb the polar compounds more actively than the surface of iron oxide. These results Were revealed from the autoradiography of the adsorption. Contributed by the ASLE Technical Committee on the Properties of Lubricants and presented at the Annual Meeting of the Amer...

Preparation and properties of some organo-cobalt and -iron complexes with triphenylphosphine as ligand

Reactions of iron(III) and cobalt(III) acetylacetonates with trialkylaluminum compounds or dialkylaluminum monoethoxide in the presence of triphenylphosphine have been studied. The reactions proceed through the exchange of the acetylacetonato ligands of Fe(acac)3 or Co(acac)3 with the alkyl groups of the organoaluminum compounds and the reaction intermediates C2H5Fe(acac)(PPh3)3(I) and Co(C2H4)(acac)(PPh3) (III) were isolated. The further reaction of III with (C2H5)2Al(OC2H5) gave Co(C2H4)(PPh3)3 (IV) which may also be obtained by the direct reaction of Co(acac)3, (C2H5)2Al(OC2H5) or (C2H5)3Al and PPh3. Use of trimethylaluminum or dimethylaluminum monoethoxide gave no intermediate alkylation product having the acetylacetonato ligand but afforded (CH3)2Fe(PPh3)3 (II), CH3Co(PPh3)2 (V) and CH3Co(PPh3)3 (VI). The isolated organo-iron and -cobalt complexes were characterized by analysis, chemical reactions, IR spectra, and magnetic susceptibility measurement.

The electronic structures of fluorinated polyacetylenes. A design of new organic polymer alternatives to polyacetylene

Abstract The electronic structures of polyfluoroacetylene and polydifluoroacetylene are discussed on the basis of the tight-binding LCAO-SCF-MO calculations under the CNDO/2 approximations. A method of preparation of these polymers is also proposed. If they can be successfully prepared, they will be promising candidates for new electric conducting materials as alternatives to polyacetylene.

A Kinetic Study on the Reaction of Labeled Sulfur Compounds with Steel Surfaces during Boundary Lubrication

The kinetic study of the reaction between steel surfaces and lubricants containing labeled sulfur compounds was carried out by using an NACA-type friction machine with line contact. When the line contact apparatus is used, a correction term should be added to the theoretical equation for a point contact to apply the empirical results. Apparently the effective surface concentration of sulfur compounds decreased markedly as the sliding velocity increased in speed. Elementary sulfur had less than good lubricating properties and readily made surface temperatures rise, but both dibenzyl disulfide and diphenyl disulfide behaved as effective lubricants over the whole range of sliding velocities. The increase of compressive pressure on frictional surface did not affect the chemical activity of the sulfur compounds, but did increase the reacting regions of frictional surface. The thickness of FeS film effective in the reduction of friction was calculated to be about 30–50 layers of FeS under dynamic conditions. Th...

Polyacetylene film: A new electrode material for photoenergy conversion

Abstract Polyacetylene films were characterized as an electrode material in aqueous solutions. The trans polyacetylene films behaved as electrodes under reducing conditions. Oxygen gas evolution was greatly retarded under oxidizing conditions, primarily due to the high reactivity with oxygen. Visible light illumination resulted in a positive shift in electrode potential. The electrode developed photopotential reversibly in accord with illumination. The polyacetylene electrode gave cathodic photocurrent when contacted with a deoxygenated acetate buffer. The cathodic photocurrent increased with decreasing pH, ranging from 0 to 5.5 × 10−6 A/cm2. The possible use of polyacetylene electrodes for photoenergy conversion is discussed.

Fixation of nitrogen by a TiCl3–Mg system. Isolation and properties of titanium complexes containing reduced nitrogen

From a system of TiCl3, tetrahydrofuran, magnesium, and nitrogen, titanium complexes containing reduced nitrogen have been isolated.