共查询到20条相似文献,搜索用时 203 毫秒
1.
Revathy Rajagopal Vishnu R. Ajgaonkar 《Monatshefte für Chemie / Chemical Monthly》2002,133(11):1387-1395
Summary. Double rare earth monomethylammonium selenates of the general formula CH3NH3
Ln (SeO4)2·5H2O (Ln = Sm, Eu, Gd, Tb, Ho, Y) were synthesized and characterized using X-ray powder diffraction and infrared spectroscopy. The
thermal decomposition of the compounds were investigated using TG, DTG, and DTA techniques.
Corresponding author. E-mail: vrajgaonkar@yahoo.com, vrajgaonkar@mail.mu.ac.in
Received November 5, 2001. Accepted (revised) March 6, 2002 相似文献
2.
Summary. Two novel Er-Cr ion-pair complexes ([Er(DMA)3(H2O)4][Cr(CN)6] and [Er(MPL)4(H2O)3][Cr(CN)6]·2H2O; DMA = dimethylacetamide, MPL = 1-methyl-2-pyrrolidinone) have been synthesized. [Er(DMA)3(H2O)4][Cr(CN)6] crystallizes in the monoclinic system (space group P
c
) with a = 9.789(2), b = 11.263(2), c = 13.997(3)?, β = 105.66(3)°, V = 1485.9(5)?3, Z = 2; [Er(MPL)4(H2O)3][Cr(CN)6]·2H2O crystallizes in the monoclinic system (space group P21) with a = 9.447(2), b = 13.881(3), c = 14.673(3)?, β = 101.85(3), V = 1883.1(7)?3, Z = 2. X-Ray crystal diffraction analyses reveal that the two complexes form a hydrogen bonding network structure through the
CN group and H2O molecules. Variable temperature susceptibilities for the two complexes indicate that weak antiferromagnetic interactions
exist between cation and anion pairs through this hydrogen bonding network. 相似文献
3.
The two new compounds Mn(dien)2[MoS4] (1) and Mn(dien)2[Mo2O2S6] (2) (dien = diethylenetriamine) were prepared under solvothermal conditions. Both compounds were obtained as phase-pure products. The structures consist of new [Mn(dien)2]2+ cations and isolated tetrahedral [MoS4]2− (1) or [Mo2O2S6]2− (2) anions. Between the anions and the cations, hydrogen bonding is observed. Compound 1 crystallizes in the tetragonal space group I (a = 10.219(2), c = 9.259(2) ?, Z = 2), whereas 2 crystallizes in the monoclinic space group P21/c (a = 8.703(2), b = 18.390(4), c = 14.603(3) ?, β = 103.18(3)°, Z = 4). The thermal behaviour of the thiomolybdates was investigated using difference thermoanalysis (DTA) and thermogravimetry (TG). Both compounds decompose under argon with a single endothermic signal in the DTA curve (peak maximum: 252 (1) and 242°C (2)). 相似文献
4.
Susana H. Tarulli Oscar V. Quinzani Oscar E. Piro Enrique J. Baran Eduardo E. Castellano 《Monatshefte für Chemie / Chemical Monthly》2001,132(7):779-787
Summary. The crystal structure of the title complex, [Cd(tsac)2(H2O)], has been determined by single crystal X-ray diffraction methods. It crystallizes in the monoclinic space group C2/c (a = 12.236(3), b = 8.919(3), c = 16.655(3) ?, β = 96.18(2)°, Z = 4). The molecular structure was solved from 1705 independent reflections with I > σ(I) and refined to R
1 = 0.0489. Infrared and Raman spectra of the complex were recorded and are briefly discussed. Its thermal behaviour was investigated by thermogravimetry
and differential thermal analysis.
Received December 18, 2000. Accepted February 19, 2001 相似文献
5.
Susana H. Tarulli Oscar V. Quinzani Oscar E. Piro Enrique J. Baran Eduardo E. Castellano 《Monatshefte für Chemie / Chemical Monthly》2001,29(5):779-787
The crystal structure of the title complex, [Cd(tsac)2(H2O)], has been determined by single crystal X-ray diffraction methods. It crystallizes in the monoclinic space group C2/c (a = 12.236(3), b = 8.919(3), c = 16.655(3) ?, β = 96.18(2)°, Z = 4). The molecular structure was solved from 1705 independent reflections with I > σ(I) and refined to R 1 = 0.0489. Infrared and Raman spectra of the complex were recorded and are briefly discussed. Its thermal behaviour was investigated by thermogravimetry and differential thermal analysis. 相似文献
6.
Summary. The two new compounds Mn(dien)2[MoS4] (1) and Mn(dien)2[Mo2O2S6] (2) (dien = diethylenetriamine) were prepared under solvothermal conditions. Both compounds were obtained as phase-pure products. The
structures consist of new [Mn(dien)2]2+ cations and isolated tetrahedral [MoS4]2− (1) or [Mo2O2S6]2− (2) anions. Between the anions and the cations, hydrogen bonding is observed. Compound 1 crystallizes in the tetragonal space group I (a = 10.219(2), c = 9.259(2) ?, Z = 2), whereas 2 crystallizes in the monoclinic space group P21/c (a = 8.703(2), b = 18.390(4), c = 14.603(3) ?, β = 103.18(3)°, Z = 4). The thermal behaviour of the thiomolybdates was investigated using difference thermoanalysis (DTA) and thermogravimetry
(TG). Both compounds decompose under argon with a single endothermic signal in the DTA curve (peak maximum: 252 (1) and 242°C (2)).
Received November 5, 2001. Accepted December 27, 2001 相似文献
7.
L. N. Zelenina T. P. Chusova I. G. Vasilyeva 《Journal of Thermal Analysis and Calorimetry》2010,101(1):59-62
A detailed thermodynamic study of the systems LnSe2–LnSe1.5 (Ln = La, Nd) was performed by static method of vapour pressure measurement using quartz membrane-gauge manometers within the
temperature range 713–1,395 K. The p
Se–T–x dependences obtained in this study have shown that the phase regions in composition intervals studied consist of discrete
phases: LnSe1.95
LnSe1.90, LnSe1.85, LnSe1.80 (Ln = La, Nd). The enthalpies and the entropies for the stepwise dissociation process were calculated from the experimental data.
The standard enthalpies of formation and the absolute entropies were estimated for the compounds investigated using literature
data. 相似文献
8.
Summary. Single crystals of sodium dithiophosphate undecahydrate (Na3PO2S2 · 11H2O) and sodium trithiophosphate undecahydrate (Na3POS3 · 11H2O) were grown from aqueous solution. The crystal structures of Na3PO2S2 · 11H2O (P212121; a = 1248.1(1), b = 945.2(1), c = 1383.1(1) pm; R
1 = 0.0202, wR
2 = 0.0502) and Na3POS3 · 11H2O (Pna21; a = 1262.0(2), b = 947.6(2), c = 1431.5(2) pm; R
1 = 0.0720, wR
2 = 0.1371) are related to each other in a sense that all constituting units are arranged in similar positions and with similar
orientations. The geometries of the anions were determined with high accuracy; thus, the structural parameters of the POS3−
3 anion were measured for the first time.
Received September 25, 2001. Accepted January 21, 2002 相似文献
9.
Carbohydrazide is prepared by reacting dimethyl carbonate with hydrazine hydrate. Its single crystal has been cultured with slow evaporation method. Its molecular structure and crystal structure have been determined by X-ray single crystal diffraction technique. The obtained results shows that the crystal belongs to Crystal system of Monoclinic, space group P2(1)/n with crystal parameters of a = 3.725(1), b = 8.834(2), c = 11.96(3), β = 91.97(1)°, V = 392.23(2) 3, Z = 4, D
c = 1.522 g/cm3, μ = 0.128 mm−1, F0 0 0) = 192. Based on the crystal data, we have also carried quantum chemistry calculations on the title compound using the B3LYP and MP2 method with cc-pVTZ basis set. The calculation results further demonstrate the molecular structure of title compound and its coordination properties. 相似文献
10.
Matthias Weil Franz Werner Frank Kubel 《Monatshefte für Chemie / Chemical Monthly》2002,229(1):267-275
Single crystals of MgAl2F8(H2O)2 have been obtained under hydrothermal conditions (250°C, 14 d) from a starting mixture of AlF3 and MgAlF5(H2O)2 in a 5% (w/w) HF solution. The crystal structure has been determined and refined from single crystal data (Fmmm (#69), Z = 4, a = 7.2691(7), b = 7.0954(16), c = 12.452(2) ?, 281 structure factors, 27 parameters, R(F 2 > 2σ (F 2)) = 0.0282, wR(F 2 all) = 0.0885). The obtained crystals were systematically twinned according to (010/100/001) as twinning matrix, reflecting the pseudo-tetragonal metric. The crystal structure is composed of perowskite-type layers built of corner sharing AlF6 octahedra with an overall composition of AlF4 − which are connected via common fluorine atoms of [MgF4/2(H2O)2/1] octahedra. Group-subgroup relations of MgAl2F8(H2O)2 to WO3(H2O)0.33 and to other M(II)M(III)2 F8(H2O)2 structures are briefly discussed. Above 570°C, MgAl2F8(H2O)2 decomposes under elimination of water into α-AlF3, β-AlF3, and MgF2. 相似文献
11.
Wiesława Ferenc B. Cristóvão J. Sarzyński Maria Wojciechowska 《Journal of Thermal Analysis and Calorimetry》2007,88(3):877-883
4-Chloro-2-methoxybenzoates of light lanthanides(III) were obtained as mono-, di-or trihydrates with metal to ligand ratio
of 1:3 and general formula Ln(C8H6ClO3)3·nH2O, where n=1 for Ln=Ce, Pr, n=2 for Ln=Nd, Sm, Eu, Gd and n=3 for Ln=La. The complexes were characterized by elemental analysis, IR spectra, thermogravimetric studies, X-ray diffraction and
magnetic measurements. The carboxylate group appears to be a symmetrical bidentate, chelating ligand. All complexes seem polycrystalline
compounds. Their thermal stabilities were determined in air. When heated they dehydrate to form anhydrous salts which next
are decomposed to the oxides of the respective metals. The solubilities of light lanthanide(III) 4-chloro-2-methoxybenzoates
in water at 293 K are of the order of 10−5 mol dm−3. The magnetic moments were determined over the range of 77–300 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 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
12.
Peter Klampfer Primož Benkič Maja Ponikvar Ana Rahten Antonija Lesar Adolf Jesih 《Monatshefte für Chemie / Chemical Monthly》2003,134(1):1-9
Summary. Hydrazinium(+2) fluoroarsenate(III) fluoride was prepared by the reaction of hydrazinium(+2) fluoride and liquid arsenic
trifluoride. N2H6AsF4F is stable at 273 K, but decomposes slowly at room temperature. N2H6AsF4F crystallizes in the orthorhombic space group Pnn2 with a = 774.0(2) pm, b = 1629.2(4) pm and c = 436.6(1) pm; V = 0.5506(3) nm3, Z = 4 and d
c
= 2.461 g cm−3. The structure consists of N2H6
2+ cations, AsF4
− anions, and F− anions and is interconnected by a hydrogen bonding network. Distorted trigonal-bipyramidal AsF4
− units are very weakly interconnected and form chains along the b axis. Bands in the Raman spectrum are assigned to the vibrations of N2H6
+2 cations and AsF4
− anions.
Corresponding author. E-mail: adolf.jesih@ijs.si
Received April 18, 2002; accepted July 15, 2002 相似文献
13.
Matthias Weil Franz Werner Frank Kubel 《Monatshefte für Chemie / Chemical Monthly》2002,133(3):267-275
Summary. Single crystals of MgAl2F8(H2O)2 have been obtained under hydrothermal conditions (250°C, 14 d) from a starting mixture of AlF3 and MgAlF5(H2O)2 in a 5% (w/w) HF solution. The crystal structure has been determined and refined from single crystal data (Fmmm (#69), Z = 4, a = 7.2691(7), b = 7.0954(16), c = 12.452(2) ?, 281 structure factors, 27 parameters, R(F
2 > 2σ (F
2)) = 0.0282, wR(F
2 all) = 0.0885). The obtained crystals were systematically twinned according to (010/100/001) as twinning matrix, reflecting
the pseudo-tetragonal metric. The crystal structure is composed of perowskite-type layers built of corner sharing AlF6 octahedra with an overall composition of AlF4
− which are connected via common fluorine atoms of [MgF4/2(H2O)2/1] octahedra. Group-subgroup relations of MgAl2F8(H2O)2 to WO3(H2O)0.33 and to other M(II)M(III)2 F8(H2O)2 structures are briefly discussed. Above 570°C, MgAl2F8(H2O)2 decomposes under elimination of water into α-AlF3, β-AlF3, and MgF2.
Received October 29, 2001. Accepted (revised) December 6, 2001 相似文献
14.
Felipe Gómez-de la Torre Yolanda Gutiérrez Félix A. Jalón Blanca R. Manzano Ana Rodríguez 《Monatshefte für Chemie / Chemical Monthly》2000,131(12):1267-1280
Summary. Partial removal of chloride anions from the dimer [Pd(η3-2-CH3*C3H4)(μ-Cl)]2 with AgTf(Tf = CF3SO3) followed by addition of dppm affords [Pd2(η3-Me*C3H4)2(μ-Cl)(μ-dppm)]Tf (1). The substitution of Cl− by X− (X = pz, SC6F5, S
py
) using the appropriate salts yields the new derivatives [Pd2(η3-Me*C3H4)2(μ-X)(μ-dppm)]Tf (2–4). All complexes exhibit a dinuclear half-A-frame structure with two isomers present in solution. The isomers differ in the
relative orientation of the two allyl groups (cis or trans). The isomer interconversion was studied by variable temperature 1H NMR spectroscopy. The molecular structures of 2 and 4 were solved by X-ray diffraction studies. A distorted boat conformation of the seven- or six-membered metallacycle was found
in both cases.
Received June 7, 2000. Accepted June 20, 2000 相似文献
15.
Felipe Gómez-de la Torre Yolanda Gutiérrez Félix A. Jalón Blanca R. Manzano Ana Rodríguez 《Monatshefte für Chemie / Chemical Monthly》2000,35(5):1267-1280
Partial removal of chloride anions from the dimer [Pd(η3-2-CH3*C3H4)(μ-Cl)]2 with AgTf(Tf = CF3SO3) followed by addition of dppm affords [Pd2(η3-Me*C3H4)2(μ-Cl)(μ-dppm)]Tf (1). The substitution of Cl− by X− (X = pz, SC6F5, S py ) using the appropriate salts yields the new derivatives [Pd2(η3-Me*C3H4)2(μ-X)(μ-dppm)]Tf (2–4). All complexes exhibit a dinuclear half-A-frame structure with two isomers present in solution. The isomers differ in the relative orientation of the two allyl groups (cis or trans). The isomer interconversion was studied by variable temperature 1H NMR spectroscopy. The molecular structures of 2 and 4 were solved by X-ray diffraction studies. A distorted boat conformation of the seven- or six-membered metallacycle was found in both cases. 相似文献
16.
Keiichi Satoh Toshio Suzuki Kiyoshi Sawada 《Monatshefte für Chemie / Chemical Monthly》2001,132(10):1145-1155
Summary. The molecular structures of bis-(pyridine base) complexes of cadmium(II) chloride and bromide, where the pyridine base is pyridine ( py), 3-methylpyridine (3-Me-py), 4-methylpyridine (4-Me-py), and 4-ethylpyridine (4-Et-py), were investigated by means of single-crystal X-ray diffraction and Raman spectroscopy. The crystal structures of CdCl2 py
2 (1), CdCl2(3-Me-py)2 (2), and CdCl2(4-Me-py)2 (3) were determined. All crystals are monoclinic; 1: a = 17.784(2), b = 8.666(1), c = 3.8252(7) ?, β = 91.54(1)°, space group: P21/n; 2: a = 11.89(1), b = 14.41(1), c = 3.874(6) ?, β = 92.3(1)°, space group: P21/a; 3: a = 21.091(2), b = 3.8884(5), c = 18.2317(3) ?, β = 113.64(1)°, space group: C2/c. The structures were refined to R/R
w
values (%) of 3.2/5.5, 3.0/5.0, and 3.4/5.1 for 1–3. All cadmium atoms are octahedrally coordinated with the chloride ions forming infinite di-μ-chloro polymeric linear chains
and the nitrogen atoms of the pyridine base in trans configuration. The Cd chains are oriented along the c-axis in 1 and 2 and along the b-axis in 3. The crystal structures indicate the absence of a peculiar interaction between the polymeric chains. The Raman spectra of eight complexes were measured in the range of 550–50 cm−1, and the Raman peaks originating from cadmium-halogen vibrations were assigned. The Raman spectra of 1 and 2 are quite alike in the lattice mode vibration region. The resemblance of the cadmium-halogen vibration peaks indicates the
same halogenide ion bridged octahedral structure for all complexes.
Received March 27, 2001. Accepted (revised) June 19, 2001 相似文献
17.
Y. M. Dan Y. R. Zhao Y. Liu S. S. Qu 《Journal of Thermal Analysis and Calorimetry》2006,84(3):531-534
The two complexes, [Ln(Ala)2(Im)(H2O)](ClO4)3 (Ln=Pr,
Gd), were synthesized and characterized. Using a solution-reaction isoperibol
calorimeter, standard enthalpies of reaction of two reactions: LnCl3⋅6H2O(s)+2Ala(s)+Im(s)+3NaClO4(s)=[Ln(Ala)2(Im)(H2O)](ClO4)3(s)+3NaCl(s)+5H2O(l) (Ln=Pr, Gd),
at T=298.15 K, were determined to be (39.26±0.10)
and (5.33±0.12) kJ mol–1 , respectively.
Standard enthalpies of formation of the two complexes at T=298.15
K, ΔfHΘm
{[Ln(Ala)2(Im)(H2O)](ClO4)3(s)} (Ln=Pr, Gd),
were calculated as –(2424.2±3.3) and –(2443.4±3.3)
kJ mol–1 , respectively. 相似文献
18.
Ana B. Gaspar M. Carmen Mu?oz Nicolás Moliner Vadim Ksenofontov Georgii Levchenko Philipp Gütlich José Antonio Real 《Monatshefte für Chemie / Chemical Monthly》2003,134(2):285-294
Summary. The monomeric compounds [Fe(abpt)2(NCX)2] (X = S (1), Se (2) and abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) have been synthesized and characterized. They crystallize in the monoclinic
P21/n space group with a = 11.637(2) ?, b = 9.8021(14) ?, c = 12.9838(12) ?, β = 101.126(14)°, and Z = 2 for 1, and a = 11.601(2) ?, b = 9.6666(14) ?, c = 12.883(2) ?, β = 101.449(10)°, and Z = 2 for 2. The unit cell contains a pair mononuclear [Fe(abpt)2(NCX)2] units related by a center of symmetry. Each iron atom, located at a molecular inversion center, is in a distorted octahedral
environment. Four of the six nitrogen atoms coordinated to the Fe(II) ion belong to the pyridine-N(1) and triazole-N(2) rings
of two abpt ligands. The remaining trans positions are occupied by two nitrogen atoms, N(3), belonging to the two pseudo-halide ligands. The magnetic susceptibility
measurements at ambient pressure have revealed that they are in the high-spin range in the 2 K–300 K temperature range. The
pressure study has revealed that compound 1 remains in high-spin as pressure is increased up to 4.4 kbar, where an incomplete thermal spin crossover appears at around
T
1/2 = 65 K. Quenching experiments at 4.4 kbar have shown that the incomplete character of the conversion is a consequence of
slow kinetics. Relatively sharp spin transition takes place at T
1/2 = 106, 152 and 179 K, as pressure attains 5.6, 8.6 and 10.5 kbar, respectively.
Corresponding author. E-mail: jose.a.real@uv.es
Received June 12, 2002; accepted July 1, 2002 相似文献
19.
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)3
nH2O (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).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
20.
Vladislav V. Kharton Aleksey A. Yaremchenko Evgeny N. Naumovich 《Journal of Solid State Electrochemistry》1999,3(6):303-326
The review is devoted to the analysis of experimental results on electrochemical and physicochemical properties of the perovskite-related
oxide phases obtained at scientific centers of the former Soviet Union. The main attention is focused on oxides with high
electronic conductivity, which are potentially useful as electrodes for high-temperature electrochemical cells with oxygen-ion
conducting solid electrolytes and interconnectors of solid oxide fuel cells, and on mixed ionic-electronic conductors for
oxygen separation membranes. Along with perovskite-like solid solutions based on LnMO3−δ (Ln is a rare-earth element, M = Cr, Mn, Fe, Co, Ni) and SrCoO3−δ, properties of the oxide phases Ln2MO4±δ (M = Cu, Ni, Co) with the K2NiF4-type structure are briefly reviewed.
Received: 5 November 1998 / Accepted: 26 November 1998 相似文献