Authors:I. Labadi, I. Lakos, G. Kenessey, and G. Liptay
Parent and mixed ligand complexes of manganese(II) ion were prepared with water, sulfate ion and 1,2-ethanediol as ligands.
The IR spectra and the thermoanalytical curves of the complexes were recorded. Oxygen atoms bound by one or two coordinate
bonds to the metal ion, or by hydrogen-bonds in the crystal, were observed. As for the water molecule, ‘crystal’ and ‘monohydrate’
type of 1,2-ethanediol molecules were found, depending on the type of binding of the oxygen atoms.
Mixed ligand complexes of different compositions were prepared with water, sulfate ion and 1,2-ethanediol as ligand. IR spectra and the thermoanalytical curves of the complexes were recorded. Oxygen atoms bound by one or two coordinate bonds to the metal ion, or by hydrogen-bonds in the crystal, were observed. As for the water molecule, 1,2-ethanediol molecules of crystal and monohydrate type were found, depending on the type of binding of the oxygen atoms.
Chemical compositions, crystalline structures and thermal properties of bombax cotton and natural colored cottons including
laurel green, bottle green and brown cotton were investigated by chemical analysis, SEM, IR spectra and X-ray diffraction.
The results showed that the crystallinity and crystallite sizes of laurel green cotton were lower than those of bottle green
cotton because of the excess content of suberin in the former. The crystallinity of brown cotton was similar to that of white
cotton, and bombax cotton had the lowest crystallinity but its crystallite orientation was the highest. Thermal property of
bottle green cotton was the most stable, whose decomposition temperature was higher of 30°C than that of common white cotton
because of its higher lignin content, and bombax cotton had the lowest thermal degradation temperature. But bottle green cotton
reached the highest decomposition speed and made decomposition finish within a very short time, and bombax cotton was just
Conditions for the formation of rare earth element (Y, La–Lu) 3-methylglutarates were studied and their quantitative composition
and solubilities in water at 293 K were determined (10–2 mol dm–3). The IR spectra of the prepared complexes with general formula Ln2(C6H8O4)3nH2O (n=3–8) were recorded and their thermal decomposition in the air were investigated. During heating the hydrated 3-methylglutarates
are dehydrated in one step and next anhydrous complexes decompose to oxides Ln2O3 with intermediate formation Ln2O2CO3 (Y, La, Nd–Gd) or directly to the oxides, Ln2O3, CeO2, Pr6O11 and Tb4O7 (Ce, Pr, Tb–Lu).
3-Methoxy-4-methylbenzoates of Y(III) and lanthanide(III) (La-Lu) were prepared as crystalline compounds with molar ratio
of metal to organic ligand of 1.0:3.0 and general formula Ln(C9H9O3)3nH2O, where n=2 for Y, La-Er and n=0 for Tm-Lu. IR spectra of the prepared complexes suggest that carboxylate groups are bidentate chelating. During heating
dihydrated complexes lose crystallization water molecules in one (Y, La, Pr-Er) or two steps (Ce) and then all the anhydrous
complexes decompose directly to oxides Ln2O3, CeO2, Pr6O11 and Tb4O7.
1,3-propanediaminotetramethylenephosphonic acid (PDTMP, H8L) was prepared and its complexes with some lanthanide ions (La(III), Eu(III), Gd(III) and Sm(III)) were isolated. The IR
spectra and thermal stabilities of PDTMP and its complexes were studied. All the complexes contain physically and coordinately
bound water molecules, which are released from the solid samples below 370C. On heating PDTMP decomposes to phosphorus oxides,
while its anhydrous complexes decompose to lanthanide oxides, and cyclic and linear polyphosphates between 400 and 1000C.
Authors:D. Czakis-Sulikowska and J. Kałużna-Czaplińska
The compounds ML2(NCS)2, (M(II)=Mn, Co), FeL2(NCS)22H2O, NiL3 NCS)23H2O (L=2,2'-bipyridine, 2-bipy) MX2(NCS)22H2O (M(II)=Mn, Fe; X=4,4'-bipyridine, 4-bipy) have been prepared and their IR spectra and molar conductivity studied. The thermal decomposition
of the complexes was studied under non-isothermal conditions in air. During heating the hydrated complexes lose crystallization
water molecules in one or two steps and then decompose via different intermediate compounds to the oxides Mn3O4, Fe2O3, CoO, NiO.
Authors:W. Brzyska, A. Tarnawska, A. Twardowska, and E Wiśniewska
Y(III) and lanthanide(III) mesaconates were prepared as crystalline solids with general formula Ln2(C5H4O4)3⋅nH2O, where n=7 for La−Pr, n=4 for Y,Nd−Ho, n=8 for Er−Lu. IR spectra of the prepared mesaconates suggest that carboxylate groups are bidentate bridging anf chelating.
During heating the hydrated complexes are dehydrated in one (Y, Nd−Lu) or two steps (La−Pr) and then decompose directly to
oxides (Y, Ce, Pr, Sm, Gd−Lu) or with intermediate formation Ln2O2CO3 (La, Nd, Eu).
New mixed-ligand complexes with empirical formulae M(4-bpy)L21.5H2O (M(II)=Mn, Co), Ni(4-bpy)2L2 and Cu(4-bpy) L2H2O (where: 4-bpy=4,4'-bipyridine, L=CC L2HCOO-) have been isolated in pure state. The complexes have been characterized by elemental analysis, ir spectroscopy, conductivity
(in methanol, dimethylformamide and dimethylsulfoxide solutions) and magnetic and x-ray diffraction measurements. The Mn(II)
and Co(II) complexes are isostructural. The way of metal-ligand coordinations discussed. the ir spectra suggest that the carboxylate
groups are bonded with metal(II) in the same way (Ni, Cu) or in different way (Mn, Co). The solubility in water is in the
order of 19.4010-31.8810-3ł mol dm-3ł. During heating the hydrate complexes lose all water in one step. The anhydrous complexes decompose to oxides via several
intermediate compounds. A coupled TG-MS system was used to analyse the principal volatile products of obtained complexes.
The principal volatile products of thermal decomposition of complexes in air are: H2O2+, CO2+, HCl+, Cl2+, NO+ and other.
for the preparation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 3-methoxy-4-methylbenzoates
were investigated and their quantitative composition and magnetic moments
were determined. The IR spectra and powder diffraction patterns of the complexes
prepared of general formula M(C9H9O3)2nH2O (n=2
for Mn, Co n=1 for Ni, Cu, n=0
for Zn, Cd) were prepared and their thermal decomposition in air was studied.
Their solubility in water at 293 K is of the order 10–2
(Mn)–10–4 (Cu) mol dm–3.
IR spectra of the prepared 3-methoxy-4-methylbenzoates suggest that carboxylate
groups are bidentate bridging. The magnetic moments for the paramagnetic complexes
of Mn(II), Co(II), Ni(II) and Cu(II) attain values 5.50, 4.45, 3.16 and 1.79
B. M., respectively. During heating the hydrated complexes lose crystallization
water molecules in one step and then the anhydrous complexes decompose directly
to oxides MO and Mn3O4. Only Co(II) complex decomposes to Co3O4
with intermediate formation CoO.