Shoji Tagashira

Distribution equilibria of aluminum-pyrocatechol violet-quaternary onium salt ion-pairs in micellar systems : Spectrophotometric Determination of Aluminum

Abstract The distribution equilibria of the ion-pairs of the aluminum-pyrocatechol violet complex with zephiramine, hexadecyltrimethylammonium (HTA) bromide or tetraphenyl-phosphonium (TPP) chloride were examined spectrophotometrically in surfactant micellar solutions. Hypsochromic shifts are attributed to dissolution of the ion-pair in the micelles. The TPP system was selected for aluminum determinations because the distribution of TPP ion-pair between water and Triton X-100 was less than that of the HTA or zephiramine ion-pair. A molar absorptivity of 64 000 l mol −1 cm −1 at 710 nm was obtained in 0.1% Triton X-100 solution. The proposed method was applied to the determination of aluminum in seaweed.

The ion-pair formation between dodecylsulfate and ammine-complexes of copper(II), nickel(II), zinc(II), palladium(II) and platinum(II), and the extraction behavior of the ammine-complexes by using sodium dodecylsulfate

A micellar solution of sodium dodecylsulfate (SDS) exhibits the property of being separated into two phases due to a temperature change or the addition of salts. The ammine-complexes of copper(II), nickel(II) and palladium(II) reacted with the dodecylsulfate anion to form the corresponding ion-pair, and were extracted into the SDS gel phase. The SDS plays the roles of a pairing-ion for the ammine-complexes and of an extraction medium. The ion-pair extraction mechanism was investigated; the extractability of metals was given by the function of the solubility products of the ion-pairs. This method was applied to the mutual separation of Ni(II)/Cu(II) and Pd(II)/Pt(II). The driving force for the extraction was an electrostatic interaction between the cationic complex and the surfactant anion. The use of the SDS gel as ion-exchanger is also expected.

Spectrophotometric determination of copper(II) with carbon disulfide, a secondary amine and triton X-100

Abstract Copper(II) is determined by non-extractive spectrophotometry as a complex of butylene dithiocarbamate formed in situ by reaction between carbon disulfide and pyrrolidine in aqueous Triton X-100 medium. This method is similar to that with butylene dithiocarbamate as starting material in the sense of simplicity, sensitivity, precision and accuracy. Pyrrolidine is the best of seven secondary amines tested in this way for copper determinations.

Synthesis of 2-Chloro-8-(2-pyridyl)-1-azaazulene and Its Metal Complexes

Reaction of 2-chloro-1-azaazulenes with 2-pyridyllithium followed by dehydrogenation by chloranil gave 8-(2-pyridyl) -1-azaazulene (2). Formation of metal complexes (M = Cu, Fe, Pd) of 2 was achieved. The reaction of 2 with Cu(1) gave 1:1-complex (3) and 2:1-complex (4). Complex (3) was deduced to have a polymeric chain structure with the copper center is +1. The ESR spectrum study of 4 showed that the copper center is +2. The structure of 4 was decided by X-Ray structural analysis and it is shown that the complex takes a trigonal bi-pyramidal structure.

Simultaneous kinetic determination of secondary amines and their isomers by a spectrophotometric stopped-flow method based on the formation of dialkyldithiocarbamates

Abstract Secondary amines react with carbon disulphide to form stable dialkyldithiocarbamates at high pH in aqueous Triton X-100 solution. The formation rates of dimethyl-, diethyl-, di- n -propyl-, diisopropyl-, di- n -butyl- and diisobutyldithiocarbamates and pyrrolidinedithiocarbamate were measured by a stopped-flow spectrophotometric method. The reaction rates were a function of the pH of the solution and depended on the size and structure of the amines. The rate of isoalkylamines was far slower than that of the n -alkyl analogues. Individual concentrations of amines were determined in a mixture of di- n - and diisopropylamine and in a mixture of diiso- and di- n -butylamine.

SYNTHESES OF 2-FORMYL-, 2,3-DIFORMYL- AND 8-FORMYL-1- AZAAZULENES

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐ Styryl-1-azaazulenes were synthesized by two ways: a) Suzuki coupling of 2-bromo-1-azaazulenes with trans-2-phenylvinylboronic acid b) Condensation of 2-methyl-1-azaazulene, being synthesized by

Synthesis and reactions of 3-ethynyl-2-(triphenylphosphoimino)-1-azaazulenes

Trimethylsilylethynyl)- and 3-(phenylethynyl)-2-(triphenyl- phosphoimino)-1-azaazulenes were synthesized by the Appel reaction of the corresponding 2-amino-3-ethynyl-1-azaazulenes. Reaction of 3-(phenyl- ethynyl)-2-(triphenylphosphoimino)-1-azaazulene (8b) with Cu(OTf)2 gave 3-(2-oxophenethyl)-2-(triphenylphosphoimino)-1-azaazulene (11), 3-(1,2-dioxo- phenethyl)-2-(triphenylphosphoimino)-1-azaazulene (12), and 2-amino-3-(1,2- dioxophenethyl)-1-azaazulene (13). The structure of 13 was decided by X-ray structure analysis, and the structure of 12 was discussed by molecular orbital calculation. Reaction of 8b with aryl isocyanate in the presence of benzoyl peroxide gave 1,10-diazabenz(a)azulene derivative.