Showing papers on "Ionic liquid published in 1969"

Viscosity and conductance micellar studies in molten pyridinium chloride

Abstract: Viscosity and conductance measurements in cetyldimethylbenzylammonium chloride solutions in molten pyridinium chloride are in agreement with other studies that indicate that micellization commences at 0.06-0.07m at 155°. Effective molal volumes, bulk viscosities, and equivalent conductivities for this system and a comparison system (anilinium chloride as solute), have been calculated. The data suggest that around 0.12m the micelles are stabilized in a size distribution comprised mainly of asymmetric micelles. Molten pyridinium chloride behaves ultrasonically as an associated liquid. The densities and viscosities of 0.5M KCl sucrose solutions (25-40% sucrose) are also supplied as calibration data for electroviscometers in the range 2-5 cP.

Phosphonium salts. I. The alkaline hydrolysis of some bis-phosphonium salts

Abstract: Ethane- and ethene-1,2-bisphosphonium salts are cleaved by alkali into a phosphine and a phosphine oxide with loss of the two-carbon bridge. When the phosphorus atom carries benzyl substituents, loss of the benzyl groups is competitive with loss of the bridge. Based on a kinetic study, a synchronous mechanism, analogous to the alkaline hydrolysis of acyclic monophosphonium salts, is proposed to account for the fragmentation. With 6-membered 1,4-diphosphonio heterocyclic salts the nature of the products is dependent on whether alkali or phosphonium salt is present in excess. With an excess of alkali a synchronous mechanism again appears to operate, while with an excess of salt the reaction proceeds stepwise and without loss of the bridge. A partial explanation of these facts is advanced in terms of non-bonded interactions in the intermediate phosphoranes. The synchronous reaction appears to be favoured by coplanarity of the P-C-C-P system.

Cobalt(II) complexes of 2,3,5,6-Tetrakis(2-pyridyl)pyrazine and 2,4,6-Tris-(2-pyridyl)-1,3,5-triazine

Abstract: Bis-ligand cobalt(II) complexes of 2,4,6-tris(2-pyridyl)-1,3,5-triazine and 2,3,5,6.tetrakis(2-pyridyl)pyrazine have been prepared. The conductivities of the complexes in nitromethane solution correspond to values expected for bi-unielectrolytes. The temperature dependence of their magnetism has shown that in some instances there exists a spin-state equilibrium in the metal atom while in others the metal atom is spin-free and Curie-Weiss laws are obeyed.

The formation of hydroxy and chloro complexes of iron(III) in chloride and perchlorate media

Abstract: The hydrolysis of iron(III) has been studied by spectrophotometric methods in KaClO4, NaCl, and CaCl2 solutions all of the same ionic strength 0.15M. The measured values of the hydrolysis constants, expressed in a form which allows for association of iron with the supporting medium, were 14.5 x 10-4 in NaClO4, 8.8 x 10-4 in NaCl, and 10.9 x 10-4 in CaCl2. In addition, the extent of complex formation between iron(III) and chloride ions has been measured in perchlorate solutions of the same ionic strength 0.15M. Assuming that only chloro complexes were formed in these systems, the stability constant of FeCl2+ formation was found to be 4.0. All the results obtained were sufficiently consistent with each other, within experimental error, that the inclusion of terms to account for iron-perchlorate association was unwarranted. However, if iron-perchlorate association was assumed to exist and the results were treated accordingly, the stability constant of the associated complex was estimated to be 1.8.

The ionization constants of phenolic groups in hydroxynaphthalenesulphonic acids

Abstract: Ionization constants of the hydroxyl group have been determined for a series of hydroxynaphthalenesulphonic acid salts. Thermodynamic pKa values have been determined for one mono- and one di-sulphonate. The effect of ionic strength is twice as great for the sulphonates as for naphthols. A large difference in acid strength between 1- hydroxynaphthalene-2-sulphonate and 2-hydroxynaphthalene-1-sulphonate has been explained in terms of interaction with the peri-hydrogen atom in the latter. Dewar and Grisdale's expression for substituent effects has been applied to the hydroxynaphthalenesulphonates with nonadjacent substituents. It is concluded that the limitations of the FM treatment are most severe with strongly dipolar substituents and with reaction sites such as -OH and -NH, capable of inducing secondary resonance effects.

Phosphonium salts. II. The reaction of bis-phosphonium salts with metal hydrides

Abstract: Ethane-1,2-bis-phosphonium salts are cleaved by sodium hydride to phos- phines in 55-80% yields with loss of the two-carbon bridge. The reaction is independent of the substituents at the phosphorus atoms. The same reaction is observed with an ethene-1,2-bis-salt and with but- 2-ene-1,4-bis(triphenylphosphonium) dibromide. It is suggested that a phosphorane is formed which subsequently fragments in a manner analogous to alkaline hydrolysis. Lithium aluminium .hydride behaves similarly but loss of the bridge is competitive with loss of benzyl groups, and yields are generally better (> 70%).

Addition compounds of aldehydes

Abstract: Equilibrium constants at 298°K have been measured spectrophotometrically for the following reactions in water: (i) Hydrogen-bonded addition of the aldehyde hydrates ethane, propane-, and butane-1,1-diols to the anions chloride, acetate, hydrogen carbonate, hydrogen phosphate, and dihydrogen phosphate. (ii) Nucleophilic addition of imidazole to the aldehydes ethanal, propanal, and butanal. (iii) Hydration (to 1,1-diols) of ethanal, propanal, 2- methylpropanal, and butanal. P.m.r. and kinetic evidence is presented to support the assumed nature of the equilibria discussed.

The thermokinetics and integral thermal effects of the action of various liquids on some protein fibres

Abstract: The thermokinetics and integral thermal effects of the action of methanol, ethanol, n-propanol, n-butanol, and acetic acid on u~ool, silk, and casein fibre Wipolan have been studied by a microcalorimetric method. It has been found that the rate of penetration depends first of all on the structure of accessible regions in protein fibres and on the dimensions of the penetrant molecule and its ability to react with functional groups of these fibres. By selecting a penetrant molecule of suitable dimensions one may cause the penetration process to become a slow phenomenon, being a characteristic for the structure of accessible regions in the given fibre. Such penetrant liquids for protein fibres are ethanol and acetic acid. It has been shown that the accessible phase in protein fibres has a discontinuous structure within the spacing of structural elements in the intermicrofibrillar and intermolecular regions.