Semiconducting organic polymer from polyacrylamide–Cu++ chelate and iodine

Semiconducting organic polymer was obtained by the modification of polyacrylamide (PAAm)–Cu⁺⁺ chelate with iodine in acetone. Favorable conditions for preparing the chelate effective for the conduction were investigated. Surface resistivities were affected by the amounts of cupric salts and iodine, satisfactory results being given by about 25 wt % of the salts based on PAAm and more than 1 wt % of iodine on the chelate. The conductivity was also varied with the degree of neutralization of the chelate in solution, and optimal values were obtained by addition of about an equimolar amount of potassium hydroxide to cupric salts. Effective structures of the polymer chelate in solution were assumed on the basis of the visible and the NMR spectra and potentiometric titration.     

XPS study on valence band structures of transition-metal trisulfides,TiS3, NbS3, and TaS3

Transition-metal trisulfides, TiS₃, NbS₃, and TaS₃, with a quasi-one-dimensional structure are investigated by X-ray photoelectron spectroscopic (XPS) measurements to obtain information on the valence band structures. The band structures at the Fermi level of these compounds correspond well to their transport properties. A shoulder is observed at the top of the valence band in NbS₃ and TaS₃, suggesting that this band is made up of the metal d_z² electrons. The d_z² band is occupied in NbS₃ and TaS₂ and empty in TiS₃. The characteristic features at the top of the valence band in NbS₃ imply the occurrence of d_z² band separation, which leads to a semiconducting nature.     

Interaction of organic dyes and proteins-determination of the binding constants spectrophotometrically

Summary The spectral change of a small molecule (S) induced by addition of a large molecule (P) was examined theoretically and experimentally, assuming that the interaction betweenS andP follows theLangmuir adsorption isotherm. It was found that intermolecular binding constants could be determined accurately and conveniently by extrapolation to zero of two simple graphic relations, namely, the observed molar extinction coefficient ofS in the presence ofP versus the ratio of (the concentration ofS/the concentration ofP), and of the former versus the reciprocal value of the latter. This spectrophotometric method was applied to the binding of bovine serum albumin and Ponceau3 R and of bovine serum albumin and HABA at p_H 7.0. The results obtained by this method were comparable with those obtained by equilibrium dialysis or by conventional spectrophotometric method.

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Zusammenfassung Unter der Annahme, daß dieLangmuirsche Absorptionsisotherme auch bei der Assoziation hoch-(HMV) und niedermolekularer Verbindungen (NMV) gilt, wurden die Bindungskonstanten bestimmt. Es wurden die spektralen Änderungen in der UV-Absorption der NMV bei Zusatz verschiedener HMV-Mengen gemessen. Die Bindungskonstanten lassen sich durch Kombination zweier graphischer Darstellungen exakt und einfach bestimmen: erstens aus der Beziehung zwischen dem molaren Extinktionskoeffizienten der NMV in Anwesenheit verschiedener HMV-Konzentrationen und dem Konzentrationsverhältnis von NMV zu HMV und zweitens aus dem Zusammenhang der molaren Extinktionskoeffizienten mit den reziproken Werten des oben genannten Konzentrationsverhältnisses. Mit dieser neuen Methode wurden die Bindungskonstanten bei p_h 7.0 von Rinderserumalbumin und Ponceau 3 R bzw. HABA berechnet und mit den durch andere Methoden bestimmten Konstanten verglichen. Die Werte stimmen mit denen aus der Dialysemethode und aus der üblichen spektralphotometrischen Methode überein.

     

Snytheses of analgesics. Part XXXVII. An alternative synthesis of 1,2,3,4, 5, 6-hexahydro-8-hydroxy-2,6-methano-6, h-dimethyl-3-phenethyl-3-benzazoeine [studies on the syntheses of heterocyclic compounds. Part DXXI]

Acid treatment of the alkylated products of (Va, Vb, and VIII) of piperidinols IVa and IVb, and tetrahydropyridine VII with β-bromoethylbenzene, afforded 1,2,3,4,5,6-hexahydro-8-hydroxy-2,6-methano-6,1 1-dimethyl-3-phenethyl-3-benzazocine (la) in good yield. Piperidinols Va and Vb were also obtained from the reaction of N-(3-methyl-3-pentenyl)-β-phenethylamine (IIb) with methyl 3-(4-methoxyphenyl)-2,3-epoxypropionate.     

Studies on the syntheses of heterocyclie compounds. Part DXXVII.. the absolute configuration of 1,2,3,4-tetrahydro-1-phenylisoquinolines

The absolute configuraiton at the C₁-position of 1,2,3,4-tetrahydro-1-phenylisoquinolines can be deduced from the CD curves of either the free base or its methiodide. Furthermore, the absolute con figuration of (⁺)-2-amino-1-(3-hydroxyphenyl)ethanol (V) was revised and found to have R-configuration at the C₁ -position.     

Alkyl chain branching in ethylene–vinyl acetate copolymer

Ethylene–vinyl acetate copolymers contain two kinds of side chains: acetoxy branches originating from incorporated vinyl acetate and alkyl branches. The alkyl branching was determined by infrared analysis after converting the ethylene–vinyl acetate copolymer to a hydrocarbon polymer by three steps: hydrolysis, iodation with hydriodic acid containing red phosphorus, and reductive hydrogenation with lithium aluminum hydride. It was found that physical properties such as stiffness were dependent both on the degree of alkyl chain branching and on vinyl acetate content.