Volume 226, Issue 4 -

The acid potassium salt of (E)-2-hydroxyimino-2-cyanoacetic acid ethyl ester (in other words: the acid Ksalt of (E)-2-cyanoethyl ester of 2-oxime or acid Ksalt of 2-oxime, or shortly speaking acid Ksalt-) has been prepared and characterized using inelastic, incoherent neutron scattering (IINS or shortly speaking INS). The last results have been compared with those obtained from optical spectroscopy. Additionally, dimers of the acid Ksalt of 2-oxime were considered i.e. vibrational frequencies of such dimers have been calculated using RB3LYP method [20] with basis set 6-311++G( d, p ). In the molecule of the acid Ksalt of 2-oxime, extra bands corresponding to hydrogen bond vibrations ( λ – bending of hydrogen bond bridge, σ – stretching of hydrogen bond bridge, γ – bending out of plane of hydrogen bond, ν – stretching –OH, δ – bending in plane of hydrogen bond have been identified, namely λ at ca. 20, σ (N–O–H···O) at 109.7, 132.3, 154.8, 206.8, 248.5, 255.1, 303.9, 339.2, 359.4, 396.6, 428.8, 483.3, 537, 577.8, 782.4, 815.3, 894.7,1108, 1165. 1408.7, γ (N–O–H···O) at 1298, ν at 1583.1 cm -1 , δ (N–OH···O) at 1734.4 and at 1847.4 cm -1 , in the low temperature IINS spectrum. Formation of the O–H···O hydrogen bridge in the acid Ksalt of 2-oxime in comparison with the same O–H···O hydrogen bridge in pure 2-oxime is reflected in shifting of the bands of the stretching (to lower) and bending vibrations (to higher) of OH group frequencies confirming the fact of increasing of hydrogen bond power in the acid Ksalt of 2-oxime in comparison with hydrogen bond power of pure 2-oxime. Additionally the fact that acid Ksalt melts ca. 50 K higher than 2-oxime and the shorter length of hydrogen in acid Ksalt than in 2-oxime confirm the greater hydrogen bond power in the acid Ksalt than in 2-oxime.

The micellar behavior of Sodium Deoxycholate (NaDC), a bile salt in presence of a neutral water soluble polymer Poly(vinylpyrrolidone) (PVP) has been investigated at four different temperatures (10–40 ºC) using conductometric, tensiometric, viscometric and fluorometric methods. NaDC is found to associate co-operatively with the polymer beyond a critical concentration, saturate the polymer completely and then undergo micellization at a higher concentration. The counter-ion binding capacity to the micelles is considerably reduced in presence of PVP. The thermodynamic properties of micellization and interfacial adsorption depend on the polymer concentration and the entropic contributions are observed to control the complexation process. The NaDC-PVP aggregate exhibits polyelectrolytic behavior. The aggregation number ( N ) and polarity index (I 1 /I 3 ) of the NaDC-PVP mixed entities have been explored by pyrene fluorescence probing technique. The values of N and I 1 /I 3 are found to be affected by [PVP] and temperature: the N values decrease with temperature while those of I 1 /I 3 show increasing trend. The dependence of N and I 1 /I 3 values on [PVP] and temperature reveal interesting insights into the NaDC-PVP complexation phenomenon.

From extraction experiments and γ -activity measurements, the exchange extraction constants corresponding to the general equilibrium M 2+ (aq)+ 1· Sr 2+ (nb)⇆ 1· M 2+ (nb)+ Sr 2+ (aq) taking place in the two–phase water-nitrobenzene system (M 2+ ߙ=ߙMg 2+ , Ca 2+ , Ba 2+ , Pb 2+ , Zn 2+ , Mn 2+ ; 1 ߙ=ߙbeauvericin; aqߙߙ=ߙaqueous phase, nbߙ=ߙnitrobenzene phase) were determined. Moreover, the stability constants of the 1· M 2+ complexes in water-saturated nitrobenzene were calculated; they were found to increase in the cation series of Mg 2+ , Zn 2+ < Mn 2+ < Pb 2+ < Ba 2+ < Ca 2+ .