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1.
Andogová E. Györyová K. Nour El-Dien F. A. 《Journal of Thermal Analysis and Calorimetry》2002,69(1):245-253
Four new complex compounds were prepared by the reaction of zinc bromobutyrate and organic ligands. The general formula of the synthetized complex compounds are (2-Brbut)2ZnL and (4-Brbut)2ZnL2nH2O (but=butyrate, L=theobromine (tbr), theophylline (tph), methyl-3-pyridyl carbamate (mpc), n=0-1). The compounds were characterized by chemical analysis and IR spectroscopy. The thermal behaviour of the zinc(II) complexes was studied by thermal analysis. Thermal decomposition in the case of hydrated compounds starts with the release of water molecules. Then molecules of organic ligands and the bromobutyrate anion are released and decomposed. CH3CH2CH=O, CO, CH2=CHCH=O, CH2O and ZnBr2 were found as gaseous products of thermal decomposition during heating up to 700°C. IR, mass spectroscopy, X-ray powder diffraction and chemical analysis were used for the determination of solid and gaseous intermediates and products of the thermal decomposition.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
2.
Renata Łyszczek 《Journal of Thermal Analysis and Calorimetry》2008,93(3):833-838
By diffusion in gel medium new complexes of formulae: Nd(btc)⋅6H2O, Gd(btc)⋅4.5H2O and Er(btc)·5H2O (where btc=(C6H3(COO)3
3−) were obtained. Isomorphous compounds were crystallized in the form of globules. During heating in air atmosphere they lose
stepwise water molecules and then anhydrous complexes decompose to oxides.
Hydrothermally synthesized polycrystalline lanthanide trimellitates form two groups of isomorphous compounds. The light lanthanides
form very stable compounds of the formula Ln(btc)⋅nH2O (where Ln=Ce−Gd and n=0 for Ce; n=1 for Gd; n=1.5 for La, Pr, Nd; n=2 for Eu, Sm). They dehydrate above 250°C and then immediately decomposition process occurs. Heavy lanthanides form complexes
of formula Ln(btc)⋅nH2O (Ln=Dy−Lu). For mostly complexes, dehydration occurs in one step forming stable in wide range temperature compounds. As the final
products of thermal decomposition lanthanide oxides are formed. 相似文献
3.
Chomič J. Györyová K. Szunyogová E. Kováéová J. 《Journal of Thermal Analysis and Calorimetry》2004,76(1):33-41
Five new complex compounds of general formula Zn(Hsal)2·L2·nH2O (where Hsal=OHC6H4COO-, L=thiourea (tu), nicotinamide (nam), caffeine (caf), theobromine (tbr), n=2-4), were prepared and characterized by chemical analysis, IR spectroscopy and studied by methods of thermal analysis (TG/DTG,
DTA). It was found that the thermal decomposition of hydrated compounds starts with the release of water molecules. During
the thermal decomposition of anhydrous compounds the release of organic ligands take place followed by the decomposition of
salicylate anion. Zinc oxide was found as the final product of the thermal decomposition heated up to 800°C. RTG powder diffraction
method, IR spectra and chemical analysis were used for the determination of products of the thermal decomposition.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2001,64(2):629-636
Thermogravimetry (TG), differential thermal analysis (DTA) and other analytical methods have been applied to the investigation
of the thermal behaviour and structure of the complexes Mg(pc)(na)3⋅3H2O (I), Mg(pc)(py)2⋅2H2O (II),Mg(pc)(pic)2⋅2H2O (III) and Mg(pc)(caf)2⋅4H2O (IV), where pc=2,6- pyridinedicarboxylate, na=nicotinamide,py=pyridine, pic=γ-picoline and caf=caffeine. The thermal decomposition of these compounds is multi-stage processes. The chemical composition of the complexes,
the solid intermediates and the resultant products of thermolysis have been identified by means of elemental analysis and
complexometric titration. Schemes of destruction of these complexes are suggested. Heating of these compounds first resulted
in a release of water molecules. In complexes I, II and IV the loss of the molecular ligands (na, py and caf) occur (on the
TG curves) in one step (-2na, -2py and -2caf) and in complex III in two steps (-pic, -pic). The final product of the thermal
decomposition was MgO. The thermalstability of the complexes can be ordered in the sequence: IV<I<III<II. Nicotinamide, pyridine,
γ-picoline and caffeine were co-ordinated to Mg(II) through the N atom of the respective heterocyclic ring. IR data suggested
a unidentate co-ordination of carboxylates to Mg(II) in complexes I–IV.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
Czakis-Sulikowska D. Czylkowska A. Malinowska A. 《Journal of Thermal Analysis and Calorimetry》2001,65(2):505-513
The new mixed ligand complexes with formulae Co(4-bpy)2L2⋅2H2O (I), Cu(4-bpy)2L2⋅H2O (II) and Cd(4-bpy)L2⋅H2O (III) (4-bpy=4,4'-bipyridine, L=CCl3COO–) were prepared. Analysis of the IR spectra indicate that 4-bpy is coordinated with metal ions and carboxylates groups bond
as bidentate chelating ligands. The electronic spectra are in accordance with pseudo-octahedral environment around the central
metal ion in the Co(II) and Cu(II) complexes. The thermal decomposition of the synthesized complexes was studied in air. A
coupled TG-MS system was used to analyse the principal volatile thermal decomposition products of Co(II) and Cu(II) complexes.
Corresponding metal oxides were identified as a final product of pyrolysis with intermediate formation of metal chlorides.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
M. Niculescu N. Vaszilcsin M. Bîrzescu P. Budrugeac E. Segal 《Journal of Thermal Analysis and Calorimetry》2001,65(3):881-889
The results of an investigation concerning there action between 1,2-propanediol and Co(NO3)2⋅ 6H2O, leading to a complex containing the lactate anion (L) as ligand are presented. The obtained solid homopolynuclear coordination compound[Co2(OH)2L2(H2O)2⋅0.5H2O]n, has been investigated by thermal analysis, electronic and IR spectroscopy and magnetic methods. Cobalt oxide obtained by
thermal decomposition of this coordinative compound was characterized by IR and X-ray spectroscopy.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
Zuzana Bujdošová Katarína Győryová Jana Kovářová Daniela Hudecová Ladislav Halás 《Journal of Thermal Analysis and Calorimetry》2009,98(1):151-159
New zinc(II) salicylate complex compounds of general formula (X-C6H3-2-(OH)COO)2Zn · Ln · xH2O (where X = H, 5-Cl; L = theophylline, urea; n = 2, 4; x = 1, 2, 4) were prepared and their thermal, spectral and biological properties were studied. It was found that the thermal
decomposition of hydrated compounds starts with the release of water. During the thermal decomposition of anhydrous compounds,
the release of salicylic acid, theophylline, urea, CO2, H2O and C6H5Cl takes place. Zinc oxide was found as the final product of the thermal decomposition heated up to 900 °C. The complexes
were tested against bacteria, yeasts and filamentous fungi. The highest biological activity show 5-chlorosalicylate compounds. 相似文献
8.
Rare earth picrate complexes
with L-leucine (Leu) were synthesized and
characterized. Elemental analysis (CHN), EDTA titrations and thermogravimetric
data suggest a general formula RE(pic)32Leu⋅5H2O
(RE=La–Lu, Y and pic=picrate).
IR spectra indicate the presence of water and suggest that L-leucine is coordinated
to the central ion through the nitrogen of the aminogroup. The absorption
spectrum of the solid Nd compound indicates that the metal-ligand bonds show
a weak covalent character. Emission spectra and biexponential behavior of
the luminescence decay of the Eu compound suggest the existence of polymeric
species. Thermal analysis results indicate that all the compounds present
a similar behavior, with five major thermal decomposition steps. The final
products are rare earth oxides. A slow heating rate is necessary to observe
all decomposition steps. 相似文献
9.
Annamária Krajníková Katarína Győryová Daniela Hudecová Jana Kovářová Zuzana Vargová 《Journal of Thermal Analysis and Calorimetry》2011,105(2):451-460
New zinc(II) 2-bromobenzoate complex compounds with general formula Zn(2-BrC6H4COO)2·nL·xH2O (where L = urea, nicotinamide, N-methylnicotinamide, N,N-diethylnicotinamide, isonicotinamide, phenazone n = 0–2, x = 0–2) were prepared and characterized by elemental analysis, IR spectroscopy and thermal analysis. The thermal decomposition
of hydrated compounds started with dehydration process. During the thermal decomposition organic ligand, carbon dioxide and
bis(2-bromophenyl)ketone were evolved. The solid intermediates and volatile products of thermal decomposition were proved
by IR spectroscopy and mass spectrometry. The final solid product of the thermal decomposition heated up to 1073 K was zinc
oxide. Antimicrobial activity of the prepared compounds was tested against various strains of bacteria, yeasts and filamentous
fungi (E. coli, S. aureus, C. albicans, R. oryzae, A. alternate and M. gypseum). It was found that the selected bacteria were more sensitive to the studied zinc(II) complex compounds than the yeast and
the filamentous fungi. 相似文献
10.
An improved method for the synthesis of four heterotrinuclearpolyacids of the type: Hx[EM′yM″zO40⋅nH2O (E=P, Si; M′=Mo, W; M″=V, W) was elaborated. The studied compounds were characterized by elemental analysis, IR spectra and thermal behaviour over
20–800°C temperature range.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
11.
Synthesis And Characterization Of Complexes Of Rare Earth Elements With 1,1-Cyclobutanedicarboxylic Acid 总被引:1,自引:0,他引:1
The complexes of yttrium and lanthanide with 1,1-cyclobutanedicarboxylic acid of the formula: Ln2(C6H6O4)3⋅nH2O, where n=4 for Y, Pr–Tm, n=5 for Yb,Lu, n=7 for La, Ce have been studied. The solid complexes have colours typical of Ln3+ ions. During heating in air they lose water molecules and then decompose to the oxides, directly (Y, Ce, Tm, Yb) or with
intermediate formation. The thermal decomposition is connected with released water (313–353 K), carbon dioxide, hydrocarbons(538–598
K) and carbon oxide for Ho and Lu. When heated in nitrogen they dehydrate to form anhydrous salt and next decompose to the
mixture of carbon and oxides of respective metals. IR spectra of the prepared complexes suggest that the carboxylate groups
are bidentate chelating.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
12.
A. Kula 《Journal of Thermal Analysis and Calorimetry》2002,68(3):957-964
Complexes of lanthanide(III) (La–Lu) and Y(III) with 1-hydroxy-2-naphthoic acid were obtained as crystalline compounds with
a general formula Ln[C10H6(OH)COO]3⋅nH2O:n=6 for La–Tm and Y, n=2 for Yb and n=0 for Lu. IR spectra of the prepared complexes were recorded, and their thermal decomposition in air were investigated. Spectroscopic
data suggest that in the coordination of metal-organic ligand only oxygen atoms from the carboxylate group take part. When
heated, the complexes decompose to the oxides Ln2O3, CeO2, Pr6O11 and Tb4O7 with intermediate formation of Ln(C11H7O3)(C11H6O3).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
A. I. El-Said 《Journal of Thermal Analysis and Calorimetry》2002,68(3):917-929
Several new mixed ligand complexes of Ni(II) and Co(II) of p-tolylsalicylaldimine (Sal-TH) or p-anisylsalicylaldimine (Sal-AH) with 8-hydroxyquinoline (HOx), benzohydroxamic acid (BH2) or α-picoline (α-pic) have been synthesized. The complexes have the general formulae: [M(Sal-T)L],[M(Sal-A)L]⋅H2O or [Ni(Sal-T)2(α-pic)2]⋅H2O where M=Ni(II) or Co(II), Sal-T=p-tolylsalicylaldiminate, Sal-A=p-anisylsalicylaldiminate, L=8-hydroxyquinolinate or benzohydroxamate and α-pic=α-picoline. Analytical, conductivity and spectral data support a square planar structure for Co(II) complexes and octahedral
structure for Ni(II) complexes. The thermal behaviour of the complexes has been studied by TG and DTG techniques. It was proposed
that the decomposition of the complexed Schiff base takes place via a radical mechanism while for 8-hydroxyquinolinate or
benzohydroxamate via proton transfer. Kinetic parameters of the thermal decomposition process have been computed by means
of Coats-Redfern and Horowitz-Metzger methods.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
14.
Györyová K. Kovářová J. Andogová E. Zeleňák V. Nour El-Dien F. A. 《Journal of Thermal Analysis and Calorimetry》2002,67(1):119-128
Zinc carboxylate complexes with N-donor ligands exhibit antimicrobial and antifungal effects. The preparation and thermal properties of complex compounds Zn(isobut)2 and Zn(isobut)2L(isobut=(CH3)2CHCOO–, L=papaverine — pap, phenazone — phen) are described in this paper. The newly synthesized compounds were characterized by elemental analysis, IR spectroscopy and TG/DTG, DTA methods.During the thermal treatment it was found that the release of organicligands (pap, phen) was followed by pyrolysis of zinc(II) isobutyrate. (C3H7)2CO and CO2 were found as gaseous products and zinc oxide as the final product of thermal decomposition. Gaseous and solid products of thermal decomposition were confirmed by chemical analysis, IR spectra and X-ray powder diffraction.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
15.
The reaction products of Cu(II) 2-chlorobenzoate and the imidazole (1), and of Cu(II) 2,6-dichlorobenzoate and the imidazole
(2) formulated as CuL’2⋅2imd⋅2H2O and CuL”2⋅2imd⋅2H2O (L’=C7H4ClO2
−, L”=C7H3Cl2O2
−, imd=imidazole), were prepared and characterized by means of spectroscopic measurements and thermochemical properties. The blue
(1) and green (2) complexes were obtained as solids with a 1:2:2 molar ratio of metal to carboxylate ligand to imidazole.
When heated at a heating rate of 10 K min−1 the hydrated complexes, (1) and (2), lose some of the crystallization water molecules and then decompose to gaseous products.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
The uranium complexes of composition,UO2X⋅N2H4⋅H2O, X=succinate or glutarate, UO2X2⋅N2H4⋅H2O, X=Hadipate, Hpimelate, Hsuberate, Hazelate and Hsebacate and UO2X⋅N2H4, where X=malate and oxydiacetate have been prepared and characterized by analytical, spectral (IR and electronic), thermal and X-ray
powder diffraction studies. Hydrazine acts as a monodentate ligand in uranyl succinate, glutarate, malate and oxydiacetate
hydrazinates and bidentate in uranyl adipate, pimelate, suberate, azelate and sebacate hydrazinate hydrate complexes. The
dicarboxylate anions bind the uranium through uni- and bidentate fashion depending upon the coordination polyhedra. All the
dicarboxylate hydrazinate complexes in this series decompose to give U3O8 as the end product through their respective uranyl dicarboxylate intermediates. Malate and oxydiacetate compounds decompose
exothermically in a single step. The coordinated water is confirmed from thermal data. The complexes of succinate to sebacate
seem to possess hexagonal bipyramidal geometry around uranium, whereas pentagonal bipyramidal geometry has been proposed for
both malate and oxydiacetate complexes.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
Hydrazinium oxydiacetate salts of formulae N2H5(Hoda)⋅H2oda, N2H5(Hoda) and (N2H5)2oda (H2oda=oxydiacetic acid) and complexes of the types, M(oda)⋅2N2H4⋅xH2O (where M=Co, Ni and Cd; x=0 for Co and Ni;x=1 for Cd) and Zn(oda)⋅N2H4⋅H2O have been prepared and characterized by analytical, spectral, thermal and X-ray powder diffraction data. IR data document
the existence of N2H+
5 ion in the simple salts and the bidentate coordination of both hydrazine and dianion in the complexes. Complete decomposition
of hydrazinium salts takes place via oxydiacetic acid intermediate. Cobalt and nickel complexes decompose in a single step,
whereas zinc and cadmium complexes decompose through hydrazinate intermediates. However, all the metal complexes yield metal
oxide as the final residue. Isomorphic nature of the cobalt and nickel complexes is evident from XRD data.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
Garrido Pedrosa A. M. Pimentel P. M. Araújo Melo D. M. Scatena H. Borges F. M. M. Souza A. G. Zinner L. B. 《Journal of Thermal Analysis and Calorimetry》2002,67(2):397-402
Ln(TFA)3⋅3AZA (Ln=La, Sm, Er; TFA=trifluoroacetate and AZA=2-azacyclononanone)compounds were synthesized and characterized by microanalytical procedures, IR spectroscopy, X-ray powder
diffraction, and thermal analysis. A kinetic study using La, Sm and Er thermogravimetric curves was carried out aiming to
proposing a mechanism for the thermal decomposition of such complexes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
The triethanolamine complexes, [M(tea)2]sq·nH2O, (n=2 for Co(II), n=0 for Ni(II), Cu(II) and n=1 for Cd(II), tea=triethanolamine, sq2−=squarate), have been synthesized and characterized by elemental analyses, magnetic susceptibility and conductivity measurements,
UV-Vis and IR spectra, and thermal analyses techniques (TG, DTG and DTA). The Co(II), Ni(II) and Cu(II) complexes possess
octahedral geometry, while the Cd(II) complex is monocapped trigonal prismatic geometry. Dianionic squarate behaves as a counter
ion in the complexes. The thermal decomposition of these complexes takes place in three stages: (i) dehydration, (ii) release of the tea ligands and (iii) burning of organic residue. On the basis of the first DTGmax of the decomposition, the thermal stability of the anhydrous complexes follows the order: Ni(II), 289°C>Co(II), 230°C>Cu(II),
226°C>Cu(II), 170°C in static air atmosphere. The final decomposition products — the respective metal oxides — were identified
by FTIR spectroscopy. 相似文献
20.
G Bannach E Schnitzler O Treu
Filho V H S Utuni M Ionashiro 《Journal of Thermal Analysis and Calorimetry》2006,83(1):233-240
Solid-state
compounds of general formula LnL3⋅nH2O,
where Ln represents heavier lanthanides
and yttrium and L is 2-chlorobenzylidenepyruvate,
have been synthesized. Chemical analysis, simultaneous thermogravimetry-differential
analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry,
elemental analysis and infrared spectroscopy have been employed to characterize
and to study the thermal behaviour of these compounds in dynamic air atmosphere.
On heating these compounds
decompose in four (Gd, Tb, Ho to Lu, Y) or five (Eu, Dy) steps. They lose
the hydration water in the first step and the thermal decomposition of the
anhydrous compounds up to 1200°C occurs with the formation of the respective
oxide, Tb4O7 and Ln2O3
(Ln=Eu, Gd, Dy to Lu and Y) as final residue.
The dehydration enthalpies found for these compounds (Eu, to Lu and Y) were:
65.77, 55.63, 86.89, 121.65, 99.80, 109.59, 131.02, 119.78, 205.46 and 83.11
kJ mol-1, respectively. 相似文献