Mamoru Nango

THE EFFECT OF UREAS UPON THE STRUCTURE OF ETHYLENE GLYCOL

The influence of ureas upon the structure of ethylene glycol is discussed. The viscosity of ureasethylene glycol solutions have been measured in the concentration range 0.2 to 1.0 in molarity at 10°, 25° and 40°C. The relative viscosities, and the viscosity B coefficient in the equation, η/η0=1+BC+DC2 have been determined, where B, D are the viscosity coefficients and C is the molarity. The viscosity data have been interpreted in terms of the temperature dependence of the B coefficient ΔB/ΔT, to find the structural change of ureas-ethylene glycol solutions. The increment of fluidity yieled by the structure-breaker in a solvent decreases the B coefficient. The increase of temperature, however, decreases the structural regularity of solvent and get the decrease of the B coefficient smaller. So, ΔB/ΔT yieled by structure-breaker gets positive, while ΔB/ΔT yieled by structuremaker gets negative as an opposite. It is concluded that in ethylene glycol, urea, of which ΔB/ΔT is negative, is a structure-maker and tetramethylurea, of which ΔB/ΔT is positive, is a structure-breaker.

INTERACTIONS BETWEEN ORGANIC IONS IN AQUEOUS SOLUTIONS

The interactions of organic cations, such as alkylamine hydrochlorides, RNH+3Cl-(R=CH3, C2H5, C3H7, C4H9) and tetraalkylammonium bromides, R4N+Br- (R=C2H5, C3H7, C4H9) with an organic anion, 2, 7-naphthalenedisulfonic acid (NDS) in aqueous solutions have been studied by using nmr spectroscopy. For comparison, the interactions of aliphatic alcohols (ROH, R=C2H5, C3H7, C4H9) with NDS were studied.The chemical shifts of aliphatic protons of such compounds in the presence of NDS were displaced to higher field (relative to external TMS). The large upfield shifts can be explained by the proximity of the aliphatic moieties to the anisotropic aromatic in aqueous solutions. In this paper were listed the shifts, Δδ, observed for alcohols, alkylamine hydrochlorides and tetraalkylammonium bromides (1 mol/l) when the medium was changed from pure water to NDS aqueous solutions (1 and 1.5 mol/l).The results obtained are as follows:(1) Alcohols. The shifts, Δδ, increased with increasing the length of the alkyl chains. Methyl and methylene proton signals were shifted to about the same extent.(2) Alkylamine hydrochlorides. The shifts increased with increasing the length of the alkyl chains. The methyl proton singals were shifted more than the methylene protons.(3) Tetraalkylammonium bromides. The shifts decreased with increasing the length of the alkyl chains. The methylene proton signals were shifted more than the methyl protons.From the above results the spatial mode of the interaction between the organic ions in aqueous solutions was discussed.

The extraction of methanesulfonic acid from water into basic organic solvent

SummaryThe extraction of methanesulfonic acid from water into a basic organic solvent, tri-n-butyl phosphate (TBP) was investigated in order to obtain the information on the state of methanesulfonic acid in TBP. This extraction was taken as a model of dyeing of nylon with acid dyes. It was found that the acid in water saturated TB P was essentially tetrahydrated. The water proton resonance in TBP relative to the external standard, tetramethylsilane, was measured. The observed proton resonance was single and moved to higher field with increasing the concentration of the acid in TBP. The result indicates that the proton in the organic phase is practically freely movable. A model of the state of methanesulfonic acid in TBP was suggested.ZusammenfassungDie Extrahierung von Methansulfonsäure aus Wasser in ein basisches und organisches Lösungsmittel, Tri-n-butylphosphat (TBP), wurde untersucht, um Aussagen über den Zustand von Methansulfonsäure in TBP zu erhalten. Die Extrahierung wurde als ein Modell für die Färbung von Nylon mit Säurefarbstoffen angesehen. Es wurde gefunden, daß die Säure im mit Wasser gesättigten TBP hauptsächlich als Tetrahydrat vorlag. Die Protonenresonanz des Wassers in TBP relativ zum äußeren Standard, Tetramethylsilan, wurde gemessen. Die beobachtete Protonenresonanz war einfach und bewegte sich nach höherem Feld mit zunehmender Konzentration der Säure in TBP. Das Resultat zeigt, daß das Proton in der organischen Phase praktisch frei beweglich ist. Eine Modellvorstellung des Zustandes von Methansulfonsäure in TBP wurde vorgeschlagen.

EXAMINATION OF DISPERSE DYE-PERCHLOROETHYLENE SOLUTIONS BY THE CONCEPT OF THE REGULAR SOLUTION

The solubilities of disperse dyes in perchloroethylene have been examined by the concept of the regular solution in order to obtain the basic information on solvent dyeing. The solubilities were determined at 5°C intervals from 5° to 40°C. From these values, the solubilities of the dyes in the super-cooled liquid state were calculated by considering the relative activity.If the solution is regular, the entropy of mixing should be ideal and the change in the partial molar entropy of the dyes in the mixing process should be expressed by the following equation, where X°11 stands for the solubility of the dye in the liquid state.The change in the partial molar entropy of the dyes in the mixing process calculated by equation (2) was compared with Δ_??_theo.Considering the simplicity of the model and the fact that the determination of the relative activity was accompanied by a considerable error, the agreement between theory and experiment was fairly good.

THE BEHAVIOR OF SULFONIC ACIDS IN NON-AQEOUS SOLVENTS

The position of the -OH proton resonance of methanesulfonic acid has been measured at various dilution in several solvents containing -OH group, such as water, methanol and ethyleneglycol. In all solvents studied, a single resonance line was observed. The proton resonance of the -OH group moves first to low field and to high field with increasing dilution. From the dilution curves it was found that in water, methanol and ethyleneglycol this movement of the -OH signal to high field commences at the following concentrations (more ratio of the sulfonic acid to the solvents); 3:1, 2:1 and 4:1. This suggests that sulfonic acid forms 3:1, 2:1 and 4:1 complexes with water, methanol and ethyleneglycol where hydrogen bonds play major roles.The chemical shifts for the ionizable proton in aqueous, methanol and ethyleneglycol solutions of methanesulfonic acid and benzenesulfonic acid have been measured at 34°C. In all cases studied, a single resonance line was observed and the proton chemical schifts dependedd upon the concentration of the acids. From the observed proton chemical shifts relative to the pure solvents, the degrees of ionization of the sulfonic acids have been calculated. The ionization constants estimated in the solvents were in the following order; water ≥ ethyleneglycol > methanol.