Authors:H.-D. Wang, Y.-T. Li, P.-H. Ma, and X.-C. Zeng
A complex of N,N'-ethylenebis(salicylideneiminato)diaquochromium(III) nitrate, [Cr(salen)(H2O)2]NO3 was characterized and its decomposition mechanism was studied by TG. The IR spectrum and X-ray analysis were examined for the complex. The non-isothermal kinetic data were analyzed by means of the Achar method and the Coats—Redfern method. The most probable kinetic model function was suggested by comparison of the kinetic parameters.
Fourteen new complexes with the general formula of Ln(Hmna)3·nH2O (n=2 for Ln=La-Ho and n=1 for Er-Lu, H2mna=2-mercaptonicotinic acid) were synthesized and characterized by elemental analyses, IR spectra and thermogravimetric analyses.
In addition, molar specific heat capacities were determined by a microcalorimeter at 298.15 K. The IR spectra of the prepared
complexes revealed that carboxyl groups of the ligands coordinated with Ln(III) ions in bidentate chelating mode. Hydrated
complexes lost water molecules during heating in one step and then the anhydrous complexes decomposed directly to oxides Ln2O3, CeO2, Pr6O11 and Tb4O7. The values of molar specific heat capacities for fourteen solid complexes were plotted against the atomic numbers of lanthanide,
which presented as ‘tripartite effect’. It suggested a certain amount of covalent character existed in the bond of Ln3+ and ligands, according with nephelauxetic effect of 4f electrons of rare earth ions.
Authors:Hélio Salvio Neto and Jivaldo do Rosário Matos
assigned to asymmetric stretching of C–O (ν as C–O) in carbonate group and symmetric stretching of C–O (y s C–O) in ester group can be also observed. The presence of these representative bands in the IRspectrum of prednicarbate treated at 220 °C confirms
Authors:M. R. Serafini, P. P. Menezes, L. P. Costa, C. M. Lima, L. J. Quintans Jr, J. C. Cardoso, J. R. Matos, J. L. Soares-Sobrinho, S. Grangeiro Jr, P. S. Nunes, L. R. Bonjadim, and A. A. S. Araújo
the aromatic ring (1614, 1506, 1465 cm −1 ), and the in-plane C–H bending (1086, 1035 cm −1 ). IRspectrum of p -cymene exhibits also two bands at 1363 and 1338 cm −1 assigned to isopropyl group. In the spectra of p -cymene/β-CD complexes obtained
distances of Mn–N are 2.284(11) and 2.095(12) Å. The O(N)–Mn–O(N) bond angles vary from 57.7(3) to 176.4(4)°.
The IRspectrum is shown in Fig. 1 . The broad absorption band centered at 3427 cm −1 shows the presence of hydrogen
and 40 mA with a Cu Ka radiation (λ = 1.5418 nm). FT-IRspectrum was recorded on a Nicolet 380 FT-IR spectrometer using KBr pellet in the wavelength range of 4,000–400 cm −1 .
FT-IR (KBr pellet, 4,000–400 cm −1 ): 3480(br), 1698(w), 1601(vs
Authors:Irena Szczygieł, Zofia Jagoda, Julia Kłak, and Maria Korabik
an IRspectrum at frequencies ν 3 = 1119 cm −1 , ν 1 = 928 cm −1 , ν 4 = 625 cm −1 and ν 2 = 459 cm −1 . Splitting of the ν 2 (doubly degenerate), and ν 3 and ν 4 (triply degenerate) bands are observed due to symmetry reduction from the
to the pure MgSO 4 [ 44 ] ( Table 4 ). The IRspectrum of compound 2 is more complex than superimposition of spectra of individual ligands ( Table 5 ). In the compound 2 , the amine exhibits shifts of some vibrations modes to higher frequencies in
Authors:J. Walczak, I. Rychlowska-Himmel, and P. Tabero
The reaction mechanism of the synthesis of Fe8V10W16O85 was studied by means of XRD, IR spectroscopy and DTA techniques. It was found that the intermediate in the reaction may be
either FeVO4 or FeVO4 admixed with an unidentified phase X, depending on the reaction temperature. The IR spectrum of the phase Fe8V10W16O85 is reported for the first time.
A new phase Cd4Fe7+xV9+xO37+4x, where −0.5<x<1.5, has been obtained in the solid-state in the FeVO4−Cd4V2O9 system. The temperature of incongruent melting and the unit cell volume of this phase decrease with decreasing the content
of cadmium. The IR spectrum and SEM image of the new phase are presented.