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1.
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
2.
W. Brzyska 《Journal of Thermal Analysis and Calorimetry》2000,59(3):799-806
The rare earth element 2,4,6-trimethylbenzoates were prepared as solids with the general formula Ln(C10 H11 O2 )3 ×n H2 O, where n =2 for Ln =Y, La–Nd, and n =1 for Ln =Sm–Lu. The IR spectra of the complexes prepared were recorded and their solubilities in water and thermal decomposition
in the air were investigated. During heating the hydrated complexes lose all the crystallization water molecules in one (Y,
Ce–Lu) or two steps (La) and then the anhydrous complexes decompose either directly to oxides (Y, Ce, Pr, Sm–Lu) or with intermediate
formation oxocarbonates Ln2 O2 CO3 (La, Nd). The carboxylate groups in the complexes prepared act probably as mono- and bidentate.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
Brzyska W. Bartyzel A. Zieniewicz K. Zwolińska A. 《Journal of Thermal Analysis and Calorimetry》2000,63(2):493-500
Rare earth element 3-methyladipates were prepared as crystalline solids with general formula Ln2(C7H10O4)3⋅nH2O, where n=6 for La, n=4 for Ce,Sm–Lu, n=5 for Pr, Nd and n=5.5 for Y. Their solubilities in water at 293 K were determined (2⋅10–3–1.5⋅10–4 mol dm–3). The IR spectra of the prepared complexes suggest that the carboxylate groups are bidentate chelating. During heating the
hydrated 3-methyladipates lose all crystallization water molecules in one (Ce–Lu) or two steps (Y) (except of La(III) complex
which undergoes tomonohydrate) and then decompose directly to oxides (Y, Ce) or with intermediate formation of oxocarbonates
Ln2O2CO3 (Pr–Tb) or Ln2O(CO3)2 (Gd–Lu). Only La(III) complex decomposes in four steps forming additionally unstable La2(C7H10O4)(CO3)2.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
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
5.
The complexes of yttrium and heavy lanthanides with 2,4-dimethoxybenzoic acid of the formula: Ln(C9H9O4)3×nH2O, where Ln=Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III) and Y(III), n=2 for Tb(III), Dy(III), Ho(III), Er(III), Tm(III)
and Y(III), and n=0 for Yb(III) and Lu(III), have been synthesized and characterized by elemental analysis, IR spectroscopy, themogravimetric
studies, as well as X–ray and magnetic susceptibility measurements. The complexes have a colour typical of Ln
3+ salts (Tb, Dy, Tm, Yb, Lu, Y – white, Ho – cream, Er – pink). The carboxylate group in these complexes is a bidentate, chelating
ligand. The compounds form crystals of various symmetry. 2,4-Dimethoxybenzoates of Yb(III) and Lu(III) are isostructural.
2,4-Dimethoxybenzoates of yttrium and heavy lanthanides decompose in various ways on heating in air to 1173 K. The hydrated
complexes first lose water to form anhydrous salts and then decompose to the oxides of respective metals. The ytterbium and
lutetium 2,4-dimethoxybenzoates decompose in one step to form Yb2O3 and Lu2O3.
The solubilities of the 2,4-dimethoxybenzoates of yttrium and heavy lanthanides in water and ethanol at 293 K are of the order
of: 10–3 and 10–3 –10–2 mol dm–3, respectively. The magnetic moments for the complexes were determined over the range of 77–298 K. They obey the Curie–Weiss
law. The results show that there is no influence of the ligand field on the 4f electrons of lanthanide ions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
Brzyska W. Tarnawska A. Twardowska A. Wiśniewska E 《Journal of Thermal Analysis and Calorimetry》2002,68(1):123-129
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).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
The complexes of yttrium and heavy lanthanides with 3,4-dimethoxybenzoic acid of the formula: Ln(C9 H9 O4 )3 ×n H2 O, where Ln =Y(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III) and Lu(III), and n =4 for Tb(III), Dy(III), n =3 for Ho(III), and n =0 for Er(III), Tm(III), Yb(III), Lu(III) and Y(III) have been prepared and characterized by elemental analysis, IR spectroscopy,
thermogravimetric and magnetic studies and X-ray diffraction measurements. The complexes have colours typical of Ln3+ ions (Ho - cream, Tb, Dy, Yb, Lu, Y - white, Er - salmon). The carboxylate group in these complexes is a symmetrical, bidentate,
chelating ligand. They are crystalline compounds characterized by various symmetry. On heating in air to 1273 K the hydrated
3,4-dimethoxybenzoates decompose in two steps while those of anhydrous only in one stage. The tetrahydrates of Tb and Dy and
trihydrate of Ho 3,4-dimethoxybenzoates are firstly dehydrated to form anhydrous salts that next are decomposed to the oxides
of the respective metals. The complexes of Er, Tm, Yb, Lu and Y are directly decomposed to the oxides of the appropriate elements.
The solubility in water at 293 K for yttrium and heavy lanthanides is in the order of 10-4 -10-3 mol dm-3 . The magnetic moments of the complexes were determined over the range 77–298 K. They obey the Curie-Weiss law. The values
of μeff calculated for all compounds are close to those obtained for Ln3+ by Hund and van Vleck. The results show that there is no influence of the ligand field on 4f electrons of lanthanide ions
in these polycrystalline compounds and 4f electrons do not take part in the formation of M-O bonding.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Z. Rzączyńska J. Sienkiewicz-Gromiuk H. Głuchowska 《Journal of Thermal Analysis and Calorimetry》2010,101(1):213-219
Rare earth complexes with 2,2′-biphenyldicarboxylic acid (diphenic acid = H2dpa) were obtained as hydrated precipitates of the general formula Ln2(C14H8O4)3∙nH2O, where n = 3 for the of Y(III) and Ce(III)–Er(III) and n = 6 for La(III), Tm(III), Yb(III) and Lu(III) complexes. On heating in air atmosphere complexes lose all water molecules in the
temperature range 30–210 °C in one step and form anhydrous compounds, which are stable up to 315–370 °C. During further heating
they decompose to oxides. The trihydrated compounds are crystalline powders whereas the hexahydrated are amorphous solids.
The trihydrated complexes crystallize in the monoclinic (Pr(III) and Ce(III) complexes) and triclinic (Y(III) and Nd(III)–Er(III)
complexes) crystal systems. 相似文献
9.
A. Kula 《Journal of Thermal Analysis and Calorimetry》2004,75(1):79-86
Complexes of lanthanides(III) (La-Lu) and Y(III) with 3,4,5-trihydroxybenzoic acid (gallic acid) were obtained and their thermal decomposition, IR spectra and solubility in water have been investigated. When heated, the complexes with a general formula Ln(C7H5O5)(C7H4O5)·nH2O (n=2 for La-Ho and Y: n=0 for Er-Lu) lose their crystallization water and decompose to the oxides Ln2O3, CeO2, Pr6O11, and Tb4O7, except of lanthanum and neodymium complexes, which additionally form stable oxocarbonates such as Ln2O2CO3. The complexes are sparingly soluble in water (0.3·10–5–8.3·10–4 mol dm–3).This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
10.
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. 相似文献
11.
Complexes of lanthanide(III) (La-Lu) and Y(III) with 4-methylphthalic acid were prepared and their IR spectra, solubility
in water at 295 K and thermal decomposition were investigated. Rare earth complexes were obtained as solids with a 2:3 ratio
of metal to organic ligand. COO– groups in the prepared complexes act as bidentate chelating and bidentate bridging. During heating they are dehydrated in
one (La-Tm) or twosteps (Yb, Lu and Y) and then decompose to the oxides Ln2O3, CeO2, Pr6O11 and Tb4O7.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
W. Ferenc A. Dziewulska-Kułaczkowska J. Sarzyński B. Paszkowska 《Journal of Thermal Analysis and Calorimetry》2008,91(1):285-292
4-Chloro-2-methoxybenzoates of heavy lanthanides(III) and yttrium(III) were obtained as mono-, di-, tri-or tetrahydrates with
metal to ligand ratio of 1:3 and general formula Ln(C8H6ClO3)3·nH2O, where n=1 for Ln=Er, n=2 for Ln=Tb, Dy, Tm, Y, n=3 for Ln=Ho and n=4 for Yb and Lu. The complexes were characterized by elemental analysis, FTIR spectra, TG, DTA and DSC curves, X-ray diffraction
and magnetic measurements.
The carboxylate group appears to be a symmetrical bidentate chelating ligand. All complexes are polycrystalline compounds.
The values of enthalpy, ΔH, of the dehydration process for analysed complexes were also determined. The solubilities of heavy lanthanide(III) 4-chloro-2-methoxybenzoates
in water at 293 K are of the order of 10−4 mol dm−3. The magnetic moments were determined over the range of 76–303 K. The results indicate that there is no influence of the
ligand field of 4f electrons on lanthanide ions and the metal ligand bonding is mainly electrostatic in nature. 相似文献
13.
The complexes of heavy lanthanides and yttrium with 2,3-dimethoxybenzoic acid of the formula: Ln(C9h9O4)3·nH2O, where Ln=Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III), Y(III), and n=2 for Tb(III), Dy(III), Ho(III), Y(III), n=1 for Er(III), Tm(III), n=0 for Yb(III) and Lu(III) have been synthesized and characterized by elemental analysis, ir spectroscopy, thermogravimetric
studies and x-ray diffraction measurements. The complexes have colours typical for Lnł3+ ions (Tb(III), Dy(III), Tm(III), Yb(III), Lu(III), Y(III) - white; Ho(III) - cream and Er(III) - salmon). the carboxylate
groups in these complexes are a symmetrical, bidentate, chelating ligand or tridentate chelating-bridging. they are isostructural
crystalline compounds characterized by low symmetry. On heating in air to 1273 k the 2,3-dimethoxybenzoates of heavy lanthanides
and yttrium decompose in various ways. The complexes of Tb(III), Dy(III), Ho(III), Er(III), Tm(III) and Y(III) at first dehydrate
to form anhydrous salts which next are decomposed to the oxides of the respective metals. 2,3-dimethoxybenzoates of Yb(III)
and Lu(III) are directly decomposed to oxides. When heated in nitrogen the hydrates also dehydrate in one step to form the
anhydrous complexes that next form the mixture of carbon and oxides of respective metals or their carbonates. The solubility
of the yttrium and heavy lanthanide 2,3-dimethoxybenzoates in water at 293 k is of the order of 10-2 mol dm-3.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
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
15.
The thermal decomposition of rare earth caproates with general formula Ln(C5H11COO)3 nH2O, (where Ln=Y, La-Pr, n=l; Ln=Nd-Er, n=2; Ln=Tm-Lu, n=3) were studied in an air atmosphere. On heating, the hydrated caproates are dehydrated in one step and then the anhydrous complexes decompose to the oxides (Ln2O3, Pr6O11) with formation of the intermediate Ln2O2CO3 (La, Pr-Gd) or directly to the oxides Ln2O3, CeO2, Tb4O7(Y, Ce, Tb-Lu). Caproates of rare earth elements are liquefied during dehydration. 相似文献
16.
The thermal decompositions of Y, La and lanthanide (from Ce(III) to Lu(III) benzene-1,2-dioxyacetates with general formula Ln2(C10H8O6)3·nH2O were studied. The hydrated complexes first lose water of crystallization in one or two steps to yield anhydrous compounds or hydrates containing coordination water molecules, and then decompose to the oxides Ln2O3, CeO2, Pr6O11 and Tb4O7 with formation of intermediates, carbonates and oxycarbonates (La, Pr-Eu), oxycarbonates (Y, Tb-Lu) or carbonate (Gd) only. Anhydrous cerium(III) benzene-1,2-dioxyacetate decomposes on heating directly to CeO2. 相似文献
17.
Qi Yang Sanping Chen Shengli Gao 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(3):357-360
Fourteen new complexes with the general formula of Ln(Hmna)3(phen) (H2mna = 2-mercaptonicotinic acid and phen = 1,10-phenanthroline) 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 complexes showed that the Ln3+ coordinated with the oxygen atoms of H2mna and the nitrogen atoms of phen. The complexes decomposed directly to oxides Ln2O3, CeO2, Pr6O11, and Tb4O7 in one step. 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.
The article is published in the original. 相似文献
18.
Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 3-methylglutarates were prepared as solids with general formula MC6 H8 O4 ×n H2 O, where n =0–8. Their solubilities in water at 293 K were determined (7.0×10−2 −4.2×10−3 mol dm−3 ). The IR spectra were recorded and thermal decomposition in air was investigated. The IR spectra suggest that the carboxylate
groups are mono- or bidentate. During heating the hydrated complexes lose some water molecules in one (Mn, Co, Ni, Cu) or
two steps (Cd) and then mono- (Cu) or dihydrates (Mn, Co, Ni) decompose to oxides directly (Mn, Cu, Co) or with intermediate
formation of free metals (Co, Ni). Anhydrous Zn(II) complex decomposes directly to the oxide ZnO.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
Summary Complexes of heavy lanthanide(III) (Gd-Lu) and Y(III) with 4-chlorophthalic acid were prepared and their IR spectra, solubility
in water at 295 K and thermal decomposition were investigated. When heated the complexes with general formula Ln2[ClC6H3(CO2)2]3·nH2O where n=6 for Tb, Dy(III), n=4 for Gd, Ho and Er(III), n=2 for Tm-Lu(III) and n=3 for Y(III) decompose to the oxides Ln2O3, Tb4O7 with intermediate formation of oxochlorides LnOCl. 相似文献
20.
Spectral,
magnetic and thermal investigations of some d-electron
element 3-methoxy-4-methylbenzoates
Conditions
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)2·nH2O (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. 相似文献