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1.
王宏社  赵立芳 《有机化学》2005,25(7):869-871
二(三氟甲基磺酰)亚胺铕(III) [Eu(NTf2)3, Tf=SO2CF3]作催化剂, 吲哚与醛(酮)在室温下发生亲电取代反应合成了一系列二吲哚基甲烷, 产率85%~98%. 该法反应条件温和、时间短、催化剂用量少且可以回收重复使用.  相似文献   

2.
Syntheses within the system CuO-SeO2-H2O revealed four copper(II)-oxo-selenites. The crystal structures of these compounds were determined by single crystal X-ray techniques. Chemical formulae, lattice parameters and space groups are: Cu2O(SeO3)-I [a=8.925 (1) Å, P213], Cu2O(SeO3)-II [a=6.987 (5) Å,b=5.953 (4) Å,c=8.429 (6) Å, =92.17 (3)°, P21/n], Cu4O(SeO3)3-I [a=15.990 (8) Å,b=13.518 (8) Å,c=17.745 (12) Å, =90.49 (5)°, P21/a], and Cu4O(SeO3)3-II [a=7.992 (6) Å,b=8.141 (6) Å,c=8.391 (6) Å, =77.34 (3)°, =65.56 (3)°, =81.36 (3)°, ].All the Cu atoms are-with one exception-[4], [4+1], and [4+2] coordinated by O atoms. The four nearest O atoms are more or less distorted square planar arranged. Within the CuO4 squares the Cu-O bond lengths are significantly shorter for the [4] coordinated O atoms as compared with those of the [4+1] and [4+2] coordinated Cu atoms. The exception in the coordination of the Cu atoms is the Cu(1) atom in Cu2O(SeO3)-I with the site symmetry 3, which is trigonal dipyramidal [5] coordinated. A common feature of these four crystal structures is, that O atoms outside the SeO3 groups are tetrahedrally coordinated by four Cu(II) atoms. The Se atoms are as usual [3] coordinated, building up SeO3 pyramids. In all these four compounds the copper-oxygen polyhedra are combined to a three-dimensional network.
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3.
Dipeptides glycyl- L -serine and L -seryl– L -tyrosine are tridentate ligands in coordination with Cu(II) through their NH2?, N–(from deprotonated amide group) and O–atom (by COO- group), forming [CuII(LH?1)H2O]. The forth position of square-planar geometry of Cu2+ is occupied by H2O as terminal ligand. Solid-state linear dichroic IR-spectroscopy, UV-Vis, mass spectrometry with ESI and FAB, tandem mass spectrometry (HPLC-MS/MS), TGV and DSC methods, EPR and magnetochemistry data prove the formation of five-membered chelate rings with participation of Cu2+ both in solution and in solid state.  相似文献   

4.
Thermal decomposition of Bi(SCN)3, Cd(SCN)2, Pb(SCN)2 and Cu(SCN)2 has been studied. The thermal analysis curves and the diffraction patterns of the solid intermediate and final products of the pyrolysis are presented. The gaseous products of the decomposition (SO2 and CO2) were detected and quantitatively determined. Thermal, X-ray and chemical analyses have been used to establish the nature of the reactions occurring at each stage in the decomposition.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

5.
An interpretative account of the results of reactions in aqueous medium of a highly peroxygenated vanadium(V) complex, K [V(O2 3]·3H2O, with different organic and inorganic substrates is presented. The reactions were monitored by solution EPR spectroscopy and isolation of products at different stages of the reactions. Redox reactions between diperoxide, K[VO(O2)2(H2O)] and VOSO4 were conducted. The results of the investigation suggest that secondary oxygen exchange-reaction occurs which not only depends on but also utilises the intermediates in the primary reaction during diperoxovanadate-dependent oxidation of VOSO4. In an interesting reactiontris(acetylacetonato)-manganese(III), Mn(acac)3, on being reacted with a hydrogen peroxide adduct, KF·H2O2, and bpy and phen afforded crystalline [Mn(acac)2(bpy)] and [Mn(acac)2(phen)], respectively. The X-ray structural analysis of [Mn(acac)2(phen)] showed that the compound crystallised in orthorhombic space groupPbcn. The structure consists of a pseudooctahedral Mn(II) ion being bound to two acac(C5H5O 2 ) and a phen ligand with the molecule lying on two-fold axis. Reactivity profiles of two new chromium(VI) reagents viz., pyridinium fluorochromate, C5H5NH[CrO3F] (PFC), and quinolinium fluorochromate C9H7NH [CrO3F] (QFC), have been presented. The compounds are capable of acting as both electron-transfer and oxygen-atom-transfer agents. The X-ray analysis of PFC crystals reveals that the compound crystallises in the orthorhombic space group CmcZ1. The structure consists of discrete pyridinium cations and CrO3 F anions with no significant hydrogen bonding. This results in total disorder of the pyridinium cation. The tetrahedral [CrO3 F] ion lies on a crystallographic mirror plane.  相似文献   

6.
The hunt for a cleaner energy carrier leads us to consider a source that produces no toxic byproducts. One of the targeted alternatives in this approach is hydrogen energy, which, unfortunately, suffers from a lack of efficient storage media. Solid-state hydrogen absorption systems, such as lithium amide (LiNH2) systems, may store up to 6.5 weight percent hydrogen. However, the temperature of hydrogenation and dehydrogenation is too high for practical use. Various molar ratios of LiNH2 with sodium hydride (NaH) and potassium hydride (KH) have been explored in this paper. The temperature of hydrogenation for LiNH2 combined with KH and NaH was found to be substantially lower than the temperature of individual LiNH2. This lower temperature operation of both LiNH2-NaH and LiNH2-KH systems was investigated in depth, and the eutectic melting phenomenon was observed. Systematic thermal studies of this amide-hydride system in different compositions were carried out, which enabled the plotting of a pseudo-binary phase diagram. The occurrence of eutectic interaction increased atomic mobility, which resulted in the kinetic modification followed by an increase in the reactivity of two materials. For these eutectic compositions, i.e., 0.15LiNH2-0.85NaH and 0.25LiNH2-0.75KH, the lowest melting temperature was found to be 307 °C and 235 °C, respectively. Morphological studies were used to investigate and present the detailed mechanism linked with this phenomenon.  相似文献   

7.
Summary The atomic arrangements within the structures of NH4Ag2(AsS2)3 [a=9.557(2),b=7.414(2),c=16.29(1) Å; =91.30(5)°; space group P21/n;R(F)=0.042] and (NH4)5Ag16(AsS4)7 [a=64.49(6),b=6.471(2),c=12.806(4) Å; =95.47(5)°; space group Cc;R(F)=0.073] were determined from single crystal X-ray data. In these two compounds the coordination spheres of the Ag atoms are quite different. In NH4Ag2(AsS2)3, the Ag atoms exhibit a [2+2]- and a [3+1]-coordination to S atoms up to 3.3 Å and with Ag atom neighbours at 2.93 Å and 3.05 Å respectively. In (NH4)5Ag16(AsS4)7, the Ag atoms are — with one exception- [4] coordinated (Ag-S<3.3 Å) and the distances to further Ag atom neighbours are greater than 3.1 Å. NH4Ag2(AsS2)3 represents an ordered cyclo-thioarsenate(III) with three-membered As3S6 rings, (NH4)5Ag16(AsS4)7 a neso-thioarsenate(V) with two split Ag atom positions. Both compounds were synthesized under moderate hydrothermal conditions.
Synthesen und Kristallstrukturen von NH4Ag2(AsS2)3 und (NH4)5Ag16(AsS4)7 mit einer Diskussion über (NH4)Sx Polyeder
Zusammenfassung Die Atomanordnungen in den Strukturen von NH4Ag2(AsS2)3 [a=9.557(2),b=7.414(2),c=16.29(1) Å; =91.30(5)°; Raumgruppe P21/n;R(F)=0.042] und (NH4)5Ag16(AsS4)7 [a=64.49(6),b=6.471(2),c=12.806(4) Å; =95.47(5)°; Raumgruppe Cc;R(F)=0.073] wurden anhand von röntgenographischen Einkristalldaten bestimmt. In diesen beiden Verbindungen sind die Koordinationsverhältnisse um die Ag-Atome sehr unterschiedlich. In NH4Ag2(AsS2)3 besitzen die Ag-Atome bis 3.3 Å eine [2+2]- und [3+1]-Koordination durch S-Atome mit weiteren Ag-Atomen bei 2.93 Å und 3.05 Å. In (NH4)5Ag16(AsS4)7 sind die Ag-Atome mit einer Ausnahme [4]-koordiniert (Ag-S < 3.3 Å), und die Abstände zu weiteren Ag-Atomen sind größer als 3.1 Å. NH4Ag2(AsS2)3 stellt ein geordnetes Cyclothioarsenat(III) mit dreigliedrigen As3S6-Ringen dar, (NH4)5Ag16(AsS4)7 ein Nesothioarsenat (V) mit zwei aufgespaltenen Ag-Positionen. Beide Verbindungen wurden unter mäßigen Hydrothermalbedingungen synthetisiert.
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8.
The new cationic mononuclear complexes [(η6-arene)Ru(Ph-BIAN)Cl]BF46-arene = benzene (1), p-cymene (2)], [(η5-C5H5)Ru(Ph-BIAN)PPh3]BF4 (3) and [(η5-C5Me5)M(Ph-BIAN)Cl]BF4 [M = Rh (4), Ir (5)] incorporating 1,2-bis(phenylimino)acenaphthene (Ph-BIAN) are reported. The complexes have been fully characterized by analytical and spectral (IR, NMR, FAB-MS, electronic and emission) studies. The molecular structure of the representative iridium complex [(η5-C5Me5)Ir(Ph-BIAN)Cl]BF4 has been determined crystallographically. Complexes 15 effectively catalyze the reduction of terephthaldehyde in the presence of HCOOH/CH3COONa in water under aerobic conditions and, among these complexes the rhodium complex [(η5-C5Me5)Rh(Ph-BIAN)Cl]BF4 (4) displays the most effective catalytic activity.  相似文献   

9.
Interaction energies between two similar plane parallel double layers for (NH4)2Fe(SO4)2 or (NH4)2Cu(SO4)2 type complex salt electrolytes at positive surface potential were expanded in a power series and accurate numeral results were given for 0.1 ≤ y e  < y 0 ≤ 20. The general expressions were given for the interaction energies of A ν +B ν′ +Cν? type complex salt electrolytes at y > 0. The interaction energies for simple salts NaCl, CaCl2, Na2SO4, FeCl3, Na3PO4, Mg3(PO4)2, Al2(SO4)3, and complex salts (NH4)2Fe(SO4)2 or (NH4)2Cu(SO4)2 at y 0 = 1 were compared. There was hardly difference between these simple salts and this complex salt for the interaction energies. The interaction energy for complex salt (NH4)2Fe(SO4)2 was close to that for simple salt Na3PO4.

Supplemental files are available for this article. Go to the publisher's online edition of the Journal of Dispersion Science and Technology to view the free supplemental file.  相似文献   

10.
Reactivity of mixtures of La(III) oxide and Cu(II) oxalate/nitrate in hydrated as well as anhydrous state was studied using TG, DTA and XRD. Cu(II) oxide formed in the endothermic decomposition of mixture containing hydrated Cu(II) nitrate and La(III) oxide could not form La2CuO4 while Cu(II) oxide formed in the exothermic decomposition of mixture containing hydrated/anhydrous Cu(II) oxalate and La(III) oxide reacts with La(III) oxide and develops the phases CuLaO3 and La2CuO4. The maximum reactivity with respect to the formation of La2CuO4phase was observed in mixture containing anhydrous Cu(II) oxalate. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

11.
The thermoanalytical curves of (C6H5)4AsCl (I) and (C6H5)4PCl (II) were generated simultaneously by using a Netzsch simultaneous thermal analyser 409 under static air and dynamic argon atmospheres. The ranges of thermal stability of I and II were found to be 145–310°C and 137–365°C, respectively, and their melting points to be 261 and 278°C. The DTA profiles of I and II differ and can be used for their distinction.  相似文献   

12.
The (μ-H)Os3{μ-OCN(Me)CH2CH=CH2}(CO)10 complex containing an allylic fragment in theN,N-dialkylsubstituted carbamoyl briding ligand was synthesized. The stereo-chemical behavior of this complex in solution was investigated. As follows from the NMR spectral data, the complex undergoes reversible conformational (about the amide C−N bond) and irreversible allylic isomerization. Both conformers were isolated in the solid state by chromatography at a reduced temperature. The allylic isomerization occurs stereospecifically to produce the (μ-H)Os3{μ-OCN(Me)CH=CHMe}(CO)10 complex with thetrans-oriented olefinic hydrogen atoms. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 158–162, January, 1998.  相似文献   

13.
The synthetic compound Pb6Cu(AsO3)2Cl7 crystallizes in space group R witha 0=9.8614(4),c 0=17.089(2)Å,Z=3. The crystal structure, determined by single crystal X-ray work, is a typical layer structure. Complex Pb6(AsO3)2Cl6 layers are combined via monovalent Cu and Cl atoms. A novel element within the structure is a [Cl3Cu(I)-As(III)O3] group with the interatomic distances (Å): Cu-Cl=2.44 (3×), As-O=1.76 (3×), Cu-As=2.34 (1×).
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14.
The three copper(II)-arsenates were synthesized under hydrothermal conditions; their crystal structures were determined by single-crystal X-ray diffraction methods:Cu3(AsO4)2-III:a=5.046(2) Å,b=5.417(2) Å,c=6.354(2) Å, =70.61(2)°, =86.52(2)°, =68.43(2)°,Z=1, space group ,R=0.035 for 1674 reflections with sin / 0.90 Å–1.Na4Cu(AsO4)2:a=4.882(2) Å,b=5.870(2) Å,c=6.958(3) Å, =98.51(2)°, =90.76(2)°, =105.97(2)°,Z=1, space group ,R=0.028 for 2157 reflections with sin / 0.90 Å–1.KCu4(AsO4)3:a=12.234(5) Å,b=12.438(5) Å,c=7.307(3) Å, =118.17(2)°,Z=4, space group C2/c,R=0.029 for 1896 reflections with sin / 0.80 Å–1.Within these three compounds the Cu atoms are square planar [4], tetragonal pyramidal [4+1], and tetragonal bipyramidal [4+2] coordinated by O atoms; an exception is the Cu(2)[4+1] atom in Cu3(AsO4)2-III: the coordination polyhedron is a representative for the transition from a tetragonal pyramid towards a trigonal bipyramid. In KCu4(AsO4)3 the Cu(1)[4]O4 square and the As(1)O4 tetrahedron share a common O—O edge of 2.428(5) Å, resulting in distortions of both the CuO4 square and the AsO4 tetrahedron. The two Na atoms in Na4Cu(AsO4)2 are [6] coordinated, the K atom in KCu4(AsO4)3 is [8] coordinated by O atoms.Die drei Kupfer(II)-Arsenate wurden unter Hydrothermalbedingungen gezüchtet und ihre Kristallstrukturen mittels Einkristall-Röntgenbeugungsmethoden ermittelt:Cu3(AsO4)2-III:a = 5.046(2) Å,b = 5.417(2) Å,c = 6.354(2) Å, = 70.61 (2)°, = 86.52(2)°, = 68.43(2)°,Z = 1, Raumgruppe ,R = 0.035 für 1674 Reflexe mit sin / 0.90 Å–1.Na4Cu(AsO4)2:a = 4.882(2) Å,b = 5.870(2) Å,c = 6.958(3) Å, = 98.51(2)°, = 90.76(2)°, = 105.97(2)°,Z = 1, Raumgruppe ,R = 0.028 für 2157 Reflexe mit sin / 0.90 Å–1.KCu4(AsO4)3:a = 12.234(5) Å,b = 12.438(5) Å,c = 7.307(3) Å, = 118.17(2)°,Z = 4, Raumgruppe C2/c,R = 0.029 für 1896 Reflexe mit sin / 0.80 Å–1.Die Cu-Atome in diesen drei Verbindungen sind durch O-Atome quadratisch planar [4], tetragonal pyramidal [4 + 1] und tetragonal dipyramidal [4 + 2]-koordiniert; eine Ausnahme ist das Cu(2)[4 + 1]-Atom in Cu3(AsO4)2-III: Das Koordinationspolyeder stellt einen Vertreter des Übergangs von einer tetragonalen Pyramide zu einer trigonalen Dipyramide dar. In KCu4(AsO4)3 haben das Cu(1)[4]O4-Quadrat und das As(1)O4-Tetraeder eine gemeinsame O—O-Kante von 2.428(5) Å, was eine Verzerrung der beiden Koordinationsfiguren CuO4-Quadrat und AsO4-Tetraeder bedingt. Die zwei Na-Atome in Na4Cu(AsO4)3 sind durch O-Atome [6]-koordiniert, das K-Atom in KCu4(AsO4)3 ist [8]-koordiniert.
Zur Kristallchemie dreier Kupfer (II)-Arsenate: Cu3(AsO4)2-III, Na4Cu(AsO4)2 und KCu4(AsO4)3
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15.
Attempts have been made to replace aluminium(III) by chromium(III) in the ettringite structure because of practical importance of a waste treatment technology. The optimum conditions of Ca6[Cr(OH)6]2(SO4)3⋅26H2O formation and its thermal stability are reported. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

16.
Using non-empirical calculations the details of bonding in Ni(CO)4 and in the analogous Ni(N2)4 are investigated.For Ni(CO)4 some previous results are confirmed. In the calculation on Ni(N2)4 the close resemblance with Ni(CO)4 is quite remarkable. The main difference is contained in the fact that carbon has a lower -electron density than nitrogen and that therefore the *-orbital in CO is lower in energy and geometrically more favourable for back donation.From the calculations we find a difference in metal-ligand bond energy between the carbonyl complex and the dinitrogen complex of approximately 18 kcal/mol.  相似文献   

17.
The crystal structure of the new phase Cu7(OH)6(TeO3)2(SO4)2 [a=7.389 (1),b=7.638 (1),c=7.662 (2) Å, =75.17 (1), =75.90 (1), =84.19 (1)°;Z=1] was determined by direct methods andFourier summations from X-ray intensities, and was refined in space group P -C i 1 toR=0.039. As usual, the Cu(II) atoms are coordinated to four O atoms forming approximately a square with average Cu-O=1.96 (3) Å; one or two more distant O neighbours complete the coordination. The shape of the TeO3 group is a rather clear-cut trigonal pyramid. A disorder was found for the SO4 tetrahedra. The compound was synthesized under hydrothermal conditions [500 (10) K, saturation vapour pressure].
Herrn Prof. Dr.K. Komarek zum 60. Geburtstag gewidmet.  相似文献   

18.
Abstract

The ligand 4-Cl-2,6-bis(benzimidazol-2′-yl)-pyridine(Cl-bzimpy;H2L) acts as a bidentate when coordinated with transition metal ions and the complex [Fe(Cl-bzimpy)2](ClO4)2 was isolated as a solid. The protonation constants (logK). The free ligand and the complex were evaluated in 30:70 (v/v) H2O:EtOH at room temperature and ionic strength of 0.13M (KCl). Coordination of the ligand to the metal ion leads to an increase of the acidity of the imino-hydrogen of the benzimidazole group. Deprotonation leads to a change in the spin-state (to the low-spin state; HS → LS transition) of the complex associated with a decrease in the spin-crossover equilibrium constant (Ksc). An opposite shift of spin-state is observed when HClO4 is added to the complex solution, thus showing the reversibility of the process.  相似文献   

19.
The heat capacities of four RE isothiocyanate hydrates, Sm(NCS)3, · 6H20, Gd(NCS)3 · 6H20, Yb(NCS)3, · 6H2O and Y(NCS)3, · 6H20, have been measured from 13 to 300 K with a fully-automated adiabatic calorimeter. No obvious thermal anomaly was observed for the above-mentioned compounds in the experimental temperature ranges. The polynomial equations for calculating the heat capacities of the four compounds in the range of 13–300 K were obtained by the least-squares fitting based on the experimentalC P, data. TheC P, values below 13 K were estimated by using the Debye-Einstein heat capacity functions. The standard molar thermodynamic functions were calculated from 0 to 300 K. Gibbs energies of formation were also calculated. Project supported by the National Natural Science Foundation of China.  相似文献   

20.
Reaction between the tridentate NNN donor ligand, (E)-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)benzo[d]thiazole (HL), and V2O5 in ethanol gave a new vanadium(V) complex, [VO2L] (1), while the similar reaction by using [VIVO(acac)2] as the metal source gave two different types of crystals related to compounds [VO2L] (1) and [VIVO(acac)L] (2). The molecular structures of the complexes were determined by single-crystal X-ray diffraction and spectroscopic characterization was carried out by means of FT-IR, UV–vis and NMR experiments as well as elemental analysis. The oxidovanadium(IV) and dioxidovanadium(V) species were used as catalyst precursors for olefin oxidation in the presence of hydrogen peroxide (H2O2) as an oxidant. Under similar experimental conditions, the presence of 1 resulted in higher oxidation conversion than 2.  相似文献   

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