The thermal behaviour of the intercalation complex of a dickite from Tarifa, Spain, with dimethylsulfoxide was studied by
high-temperature X-ray diffraction, differential thermal analysis and thermogravimetry, and attenuated total reflectance infrared
spectroscopy. The ATR-FTIR study indicated that the heating between room temperature and 75C produced the elimination of
adsorbed molecules. Above this temperature the elimination of intercalated molecules occurs through several stages. Loss of
6.5% of the intercalated DMSO first causes a slight contraction of the basal spacing at 90şC due to a rearrangement of the
DMSO molecules in the interlayers positions. This contraction is followed by the formation of a single layer complex and the
restoring of the dickite structure, at 300C, when the loss of intercalated species have been completed.
Authors:B. Marongiu, Alessandra Piras, Silvia Porcedda, and Enrica Tuveri
A flow microcalorimeter has been used to determine excess enthanlpies (HE) at 298.15 K for binary mixtures of dimethylsulfoxide (1)+alkylbenzenes (benzene, methylbenzene, ethylbenzene, n-propylbenzene and sec-propylbenzene, n-butylbenzene, sec-butylbenzene and tert-butylbenzene) or tetrachloromethane, trichloromethane, tetrachloroethane, dichloromethane and monochloroalkanes (1-chloropropane,
1-chlorobutane, 1-chloropentane, 1-chlorohexane) (2). These data with the data available in the literature on the molar excess
enthalpies (HE), molar excess Gibbs energies (GE), activity coefficients at infinite dilution, γi∞, liquid-vapour equilibria (LVE) and liquid-liquid equilibria (LLE) for dimethylsulfoxide (DMSO)+n-alkanes, cyclohexane, benzene or alkylbenzenes (mono-, dialkyl-and trialkyl-) or tetrachloromethane, trichloromethane, dichloromethane
and monochloroalkanes are treated in the framework of DISQUAC, an extended quasi-chemical group contribution theory.
The systems are characterized by three types of contact surfaces: sulfoxide (S=O group), aliphatic (CH3, CH2, CH groups), cycloaliphatic (c-CH2 group), aromatic (C6H6, C6H5 groups) and chlorine (C1 group). Using a set of adjusted contact interchange energies parameters, structure dependent, the
model provides a fairly consistent description of the thermodynamic properties as a function of concentration. The model may
serve to predict missing data.
are accessible to the grafting agents, and the interlayer space is expanded [ 4 ], The layered kaolinite particles can be intercalated by small molecules, such as urea, potassium acetate, dimethylsulfoxide (DMSO), etc. [ 11 – 14 ]. The preparation of
DMSO-kaolinite complexes of low- and high-defect Georgia kaolinite (KGa-1 and KGa-2, respectively) were investigated by thermo-XRD-analysis.
X-ray patterns showed that DMSO was intercalated in both kaolinites with a d(001)-value of 1.11 nm (type I complex). The samples were gradually heated up to 170°C and diffracted by X-ray at room-temperature.
With the rise in temperature, due to the thermal evolution of the guest molecules, the relative intensity of the 1.11 nm peak
decreased and that of the 0.72 nm peak (neat kaolinite) increased indicating that the fraction of the non-intercalated tactoids
increased. The 1.11 peak disappeared at 130–140°C. During the thermal treatment of both complexes two additional peaks appeared
at 110 and 120°C, respectively, with d-values of 0.79–0.94 and 0.61–0.67 nm in DMSO-KGa-1 and 0.81–0.86 and 0.62–0.66 nm in DMSO-KGa-2, indicating the formation
of a new phase (type II complex). The new complex was obtained by the dehydration of type I complex and was composed of intercalated
DMSO molecules which did not escape. The new peaks disappeared at 150–160°C indicating the complete escape of DMSO.
Authors:Zh. F. Gesse, G. I. Repkin, V. A. Isaeva, and V. A. Sharnin
thermochemical study of glycine (simplest amino acid) protonation and silver(I) glycine-ion complexation in aqueous-dimethylsulfoxide of various content.
Silver(I) nitrate (high purity) and
Dimethylsulfoxide (DMSO) kaolinite complexes of low-and high-defect kaolinites were studied by thermo-IR-spectroscopy analysis.
Samples were gradually heated up to 170°C, three hours at each temperature. After cooling to room temperature, they were pressed
into KBr disks and their spectra were recorded. From the spectra two types of complexes were identified. In the spectrum of
type I complex two bands were attributed to asymmetric and symmetric H-O-H stretching vibrations of intercalated water, bridging
between DMSO and the clay-O-planes. As a result of H-bonds between intercalated water molecules and the O-planes, Si-O vibrations
of the clay framework were perturbed, in the low-defect kaolinite more than in the high-defect. Type II complex was obtained
by the thermal escape of the intercalated water. Consequently, the H-O-H bands were absent from the spectrum of type II complex
and the Si-O bands were not perturbed. Type I complex was present up to 120°C whereas type II between 130 and 150°C. The presence
of intercalated DMSO was proved from the appearance of methyl bands. These bands decreased with temperature due to the thermal
evolution of DMSO but disappeared only in spectra of samples heated at 160°C. Intercalated DMSO was H-bonded to the inner-surface
hydroxyls and vibrations associated with this group were perturbed. Due to the thermal evolution of DMSO the intensities of
the perturbed bands decreased with the temperature. They disappeared at 160°C together with the methyl bands.
Authors:S. A. Dauengauer, Yu. N. Sazanov, L. A. Shibaev, T. M. Bulina, and N. G. Stepanov
The synthesis of solid complexes of bis(N-phenyl)-pyromellitic acid amide (PMA) with aprotic solvents (dimethylformamide, dimethylacetamide,N-methylpyrrolidone and dimethylsulfoxide) and their thermal analysis (evolved gas analysis using mass spectroscopy, and thermogravimetry) is described. In all cases, the composition of the complexes was found to be 1PMA: 2 solvent. The activation energy of the decomposition process of the complexes was determined from TG data. The values found were between 40 and 80 kJ/mol.
Authors:Naomi Warashina, Masahiro Tsuchiya, Kaori Ishimaru, and Takakazu Kojima
soluble in nonionic polar solvents, such as N , N -dimethylacetamide, DMA, dimethylsulfoxide, DMSO, etc., [ 1 , 2 ]. Aromatic polyamides having good solubility are industrially important, because of their ease of fabrication. Many aromatic polyamides
Materials, synthesis, and analysis
4,4′-Bipyridine, CCl 3 COOH, CHBr 2 COOH, Y 2 O 3 , La 2 O 3 , dimethylsulfoxide (DMSO), dimethylformamide (DMF), and methanol (MeOH) (anhydrous) p.a. were obtained from Aldrich and Lab-Scan. Water solutions of
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