Authors:A. Czylkowska, D. Czakis-Sulikowska, A. Kaczmarek, and M. Markiewicz
± 0.5 K, using 1 × 10 −3 mol L −1 solutions of complexes in methanol (MeOH), dimethylsulfoxide (DMSO) and dimethylformamide (DMF). The thermal properties of complexes were studied by TG, DTG and DTA techniques; TG, DTG and DTA curves were recorded on
Authors:Andrea Melchior, Marilena Tolazzi, and Silvia Del Piero
previously reported [ 10 , 11 ].
In this article, we report the results of study of the complex formation in the organic solvent dimethylsulfoxide (DMSO) between Cd(II) ion and the tripodal ligands shown in Scheme 1 : 2,2′,2″-triaminoethylamine
Enthalpies of solution of 1,4-dioxane, 12-crown-4 ether (12C4), 15-crown-5 ether (15C5) and 18-crown-6 (18C6) have been analyzed
from the point of view of preferential solvation of these cyclic ethers (crown ethers) by a molecule of acetone or dimethylsufoxide
in the mixtures of water with acetone or dimethylsulfoxide. It has been observed that the carbonyl carbon atom replacement
in acetone molecule by sulfur atom brings about completely different behavior of molecules of these solvents in relation to
cyclic ethers dissolved in mixed solvents. Crown ethers are preferentially solvated by acetone (ACN) molecules, which is not
observed in the case of dimethylsulfoxide (DMSO).
Authors:E. Katayev, G. Kolesnikov, V. Khrustalev, M. Antipin, R. Askerov, A. Maharramov, K. German, G. Kirakosyan, I. Tananaev, and T. Timofeeva
The synthesis and anion binding properties of a neutral macrocyclic receptor bearing H-bond donor coordination sites are described.
The anion binding studies by use of UV-vis and 99Tc NMR methods revealed that the receptor can coordinate perrhenate and pertechnetate in dimethylsulfoxide and chloroform
solutions with the relatively high binding constants, viz. log Ka > 4. The coordination mode of the perrhenate to the receptor was determined by a single-crystal X-ray diffraction analysis.
Authors:I. Lapides, N. Lahav, K. H. Michaelian, and S. Yariv
Intercalation complexes of kaolinite with a series of alkali halides (NaCl (trace amounts), KCl, RbCl, CsCl, NaBr, KBr, CsBr, Kl, Rbl and Csl) were obtained by a thermal solid state reaction between the kaolinite-dimethylsulfoxide intercalation complex and the appropriate alkali halide. The ground mixtures (1∶1 weight ratio) were pressed into disks that were gradually heated up to 250 °C for different times. X-ray diffractograms of the disks were recorded after each thermal treatment. At the end of the thermal treatment the disks were ground and basal spacings of the powders obtained. As a result of thermal treatment, alkali halide ions diffuse into the interlayers, replacing the intercalated dimethylsulfoxide molecules. Such a replacement may take place only if the thermal diffusion of the penetrating species is faster than the evolution of the intercalated organic molecule. With increasing temperature the intercalated salt diffused outside the interlayer space or underwent a thermal hydrolysis which resulted in the evolution of hydrogen halides from the interlayer space. Consequently, the amounts of intercalation complexes decreased at elevated temperatures.
Authors:Agnieszka Czylkowska and Mirosława Markiewicz
A novel mixed-ligand complexes with empirical formulae: Dy(4-bpy)(CCl2HCOO)3 · H2O and Ln(4-bpy)1.5(CCl3COO)3 · 2H2O (where Ln(III) = Ce, Nd) were prepared and characterized by chemical and elemental analysis and IR spectroscopy, conductivity
(in methanol, dimethyloformamide and dimethylsulfoxide). Analysis of the diffractograms showed that the obtained complexes
are crystalline. Way of metal-ligand coordination discussed. The thermal properties of complexes in the solid state were studied
under non-isothermal conditions in air atmosphere. During heating the complexes decompose via intermediate products to the oxides: Ln2O3 (Nd, Dy) and CeO2. TG-MS system was used to analyse principal volatile thermal decomposition and fragmentation products evolved during pyrolysis
of Dy(4-bpy)(CCl2HCOO)3 · H2O in air.
Authors:Mihaela Badea, Rodica Olar, Dana Marinescu, Valentina Uivarosi, and Daniela Iacob
A series of new complexes with mixed ligands of the type RuL2(DMSO)mCl3·nH2O ((1) L: norfloxacin (nf), m = 1, n = 1; (2) L: ciprofloxacin (cp), m = 2, n = 2; (3) L: ofloxacin (of), m = 1, n = 1; (4) L: enrofloxacin (enro), m = 0.5, n = 4; DMSO: dimethylsulfoxide) were synthesised and characterised by chemical analysis and IR data. In all complexes both
fluoroquinolone derivative and DMSO act as unidentate. The thermal behaviour steps were investigated in synthetic air flow.
The thermal transformations are complex processes according to TG and DTG curves including dehydration, quinolone derivative
and DMSO degradation respectively. The final product of decomposition is ruthenium (IV) oxide.
AbstractThree types of the extraction chromatographic materials, composed from Aliquat® 336 deposited in the polyacrylonitrile
(PAN) beads and prepared by different procedures, were compared for extraction of rhenium. The best properties were exhibited
when the solid extractant was prepared by impregnation of the ready-made PAN beads. Solid extractant prepared by direct coagulation
of the beads from the suspension of Aliquat® 336 in solution of PAN in nitric acid differs only by lower capacity in dynamic
conditions. Material prepared from the PAN solution in dimethylsulfoxide was the worst because Aliquat® 336 was washed out
from the beads during coagulation of the polymer and the extraction capacity was low. As it is shown, the first two solid
extractants are fully comparable with the commercial TEVA Resin.
Authors:S. Yariv, I. Lapides, K.H. Michaelian, and N. Lahav
Solid state intercalation of alkali halides into kaolinite takes place by heating pressed disks of dimethylsulfoxide (DMSO)-kaolinite
complex ground in different alkali halides. This reaction involves diffusion of the DMSO outside the interlayer space and
the alkali halide into the interlayer space. IR and Raman spectroscopy reveal two types of intercalation complexes: (i) almost
non-hydrous, obtained during thermal treatment of the DMSO complex; and (ii) hydrated, obtained by regrinding the disk in
air. The strength of the hydrogen bonds between intercalated water or halide anions and the inner surface hydroxyls decreases
in the order Cl−>Br−>I−. Chlorides penetrate the ditrigonal holes and form hydrogen bonds with the inner OH groups.
This article is dedicated to develop an experimental approach for directly visualizing the global freezing phase change behavior
of micro liquid droplets. The infrared (IR) thermograph was proposed to image the basic solidification phenomena of droplet
and to acquire its temperature variations during the transient process. In particular, the volumetric recalescence event,
regarded as initiation of freezing, was revealed by IR images for the first time. Preliminary results demonstrated that the
involved temperature transition due to release of the latent heat can be accurately characterized by evident color break in
IR images. Further, experiments were also performed simultaneously on three kinds of droplets made of pure water, dimethylsulfoxide
(DMSO) and nano liquid to grasp more precise temporal and spatial temperature distribution. Types of the occurring solidification
and the initial frozen volume produced from the recalescence were generally discussed. The IR monitoring method suggests a
straightforward way for detecting the freezing phase change activity and its temperature evolution at micro scale.