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1.
The structure of CsPd2F5 has been confirmed from neutron diffraction data on powdered sample. CsPd2F5 crystallizes in the orthorhombic Imma space group. At 100 K, the unit-cell constants are a = 6.473(2) Å, b = 7.853(5) Å, c = 10.718(3) Å and the calculation carried out using the Rietveld method leads to R1 = 0.020. The network is formed of PdF6 octahedra chains containing half of Pd in high-spin configuration, connected one to each other by square planes containing the other half of Pd in low-spin configuration. CsPd2F5 orders antiferromagnetically below TN = 38 K. In the ordered state a weak ferromagnetic component occurs (σ0 = 0.098 μB at 2 K). The magnetic structure determined at 4 K is consistent with the magnetization data and can be described in the Im′m′a′ magnetic group without any doubling of the unit-cell parameters. Within the chains, Pd2+ are coupled antiparallel. The magnetic moments are located in the (x0z) plane, the angle between the moments and the z axis being 18°. 相似文献
2.
Diorganogallium Fluorides. The Crystal Structure of the Mixed Crystal [B(CH2Ph)3]0.92[Ga(CH2Ph)3]0.08 · NCMe The reaction of GaR3 with BF3 · OEt2 in diethylether leads to the diorganogallium fluorides R2GaF [R = i-Pr ( 1 ), CH2Ph ( 2 ), Mes ( 3 )]. Compound 1 is also available by the reaction of i-Pr2GaBr ( 6 ) with KF at ?20°C in acetonitrile. The by-product B(CH2Ph)3, formed together with 2 during the first reaction, crystallizes with ca. 8% Ga(CH2Ph)3 in acetonitrile as [B(CH2Ph)3]0.92[Ga(CH2Ph)3]0.08 · NCMe ( 4 ) in the space group P21/n with a = 1050.32(7) pm, b = 1159.5(2) pm, c = 1591.6(1) pm and β = 96.931(6)°. 相似文献
3.
Masahiro Yoshida 《Tetrahedron letters》2004,45(29):5573-5575
The direct coupling of propargylic alcohols with arylboronic acids has been achieved using palladium catalyst. Various propargylic alcohols and arylboronic acids can be coupled to afford the corresponding allenic and propargylic arenes, which are selectively produced depending on the substituent on the propargylic alcohol, respectively. 相似文献
4.
Ya‐Ping Du Ya‐Wen Zhang Prof. Dr. Zheng‐Guang Yan Dr. Ling‐Dong Sun Prof. Dr. Song Gao Prof. Dr. Chun‐Hua Yan Prof. Dr. 《化学:亚洲杂志》2007,2(8):965-974
We report the synthesis of single‐crystalline and near‐monodispersed NaMF3 (M=Mn, Co, Ni, Mg), LiMAlF6 (M=Ca, Sr), and NaMgF3:Yb,Er nanocrystals (quasisquare nanoplates, nanorods, and nanopolygons) by the cothermolysis of multiple trifluoroacetates in hot combined organic solvents (oleic acid, oleylamine, and 1‐octadecene). The nanocrystals were characterized by XRD, TEM, superconductive quantum interference device (SQUID), and upconversion luminescence spectroscopy. By regulating the polarity of the dispersant, the NaMF3 (M=Mn, Co, Ni) nanoplates were partially aligned to form nanoarrays on copper TEM grids. The sizes of the NaMF3 nanocrystals were easily tuned by the use of proper synthetic conditions such as reaction temperature and time and solvent composition. On the basis of a series of experiments in which the reaction conditions were varied, together with GC–MS and FTIR analysis, the reaction pathways for the formation of these nanocrystals from trifluoroacetate precursors were proposed. The magnetic measurements showed that the differently sized NaMnF3 square plates displayed interesting weak ferromagnetic behavior on the nanometer scale. The strong red upconversion luminescence emitted from the NaMgF3:Yb,Er nanorods under 980‐nm near‐IR laser excitation suggests that NaMgF3 may be a good candidate host material for red upconversion luminescence. 相似文献
5.
Karim Adil Gilles Dujardin Marc Leblanc Vincent Maisonneuve 《Journal of fluorine chemistry》2004,125(11):1709-1714
Tren amine cations and carbonate anions adopt a ternary symmetry while tetra amine cations are tetrahedral. The symmetry of these constitutive ions influences strongly the nature of the solids which crystallise from solutions. Large fluorinated aluminate polyanions with tetrahedral symmetry appear in the presence of tren amine, while infinite chains of AlF6 octahedra are observed with tetra amine and that noncentrosymmetric structures are frequently encountered in rare earth fluoride carbonates. 相似文献
6.
G. Tav?ar 《Journal of fluorine chemistry》2004,125(11):1579-1584
A new class of coordination compounds of the type [Mn+(L)p](AF6−)n and [Mn+(L)r](BF4−)n, where M is Mg, Ca, Sr, Ba, Cd, Pb, lanthanides, A is P, As, Sb, Bi and L is XeF2, XeF4, XeF6, KrF2, was studied. A review of all known coordination compounds with L is XeF2 is given: (a) synthetic routes for the preparation of these compounds; (b) analysis of their crystal structures (molecular, dimer, chain, double chain, layer, strongly interconnected double layers and three-dimensional network); (c) the influence of the ligand XeF2 (small formula volume, linear, semi-ionic, charge of −0.5e on each F ligand); (d) the influence of the central metal ion; (e) the influence of the anions: AF6− and BF4− (the formula volume, Lewis basicity). On the basis of all properties of the metal ions, ligand and anions the obtained variety of the structures is analyzed. 相似文献
7.
Solubility of lanthanum oxide was measured by thermal analysis. The solubility in alkali cryolites is rather high, because of chemical reactions between lanthanum oxide and cryolites. In Li3AlF6-La2O3, alumina precipitates, in the other systems the mixed oxide LaAlO3 is formed. In La2O3-Li3AlF6 the eutectic point is at 9.5 mol% La2O3 and 755 °C. The eutectic points in La2O3-Na3AlF6 and La2O3-K3AlF6 are at 11.5 mol% La2O3, and at 937 and 934 °C, respectively. 相似文献
8.
Simons electrochemical fluorination (ECF) of 1,4-dimethyl-1,4-homopiperazine, methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine was studied. For comparison, ECF of three piperazines with a N-(methoxycarbonylmethyl) group(s) was also studied. ECF of 1,4-dimethyl-1,4-homopiperazine gave a low yield of corresponding perfluoro(1,4-dimethyl-1,4-homopiperazine) together with perfluoro(2,6-diaza-2,6-dimethylheptane) as the major product. Corresponding perfluoro(homopiperazines) with mono- and/or di-(fluorocarbonyldifluoromethyl) groups [CF2C(O)F] at the 1- and/or 4-position were formed in low yields from methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine, respectively. These new seven-membered perfluoro(1,4-dialkyl-1,4-homopiperazines) were accompanied by the formation of mono- and/or di-basic linear perfluoroacid fluorides resulting from the CC bond scission at the 2- and 3-positions of the ring. From mono- and/or di-N-(methoxycarbonylmethyl)-substituted piperazines, corresponding perfluoropeperazines having the acid fluoride group(s) were formed in low yields. 相似文献
9.
Patrick Gredin Ariel De Kozak Michel Quarton Jean Renaudin Grard Ferey 《无机化学与普通化学杂志》1993,619(6):1088-1094
The liquid-solid phase diagram of the binary system BaF2? ScF3 is established by D.T.A. and radiocrystallography. Three fluorides are disclosed: Ba3Sc2F12, Ba5Sc3F19 and a cubic high temperature phase Ba1?xScxF2+x (x = 0.17), the structure of which derives from that of BaF2. A solid solution between BaF2 and ScF3 is also evidenced at high temperature. The ternary system BaF2? CuF2? ScF3 is investigated by radiocrystallography and an isothermal section at 670°C is given. It shows the existence of four phases: a complex quaternary fluoride Ba10Cu12ScF47, two “polytypic” phases the structure of which derives from that of BaCuF4 and a tetragonal solid solution Ba5Sc3?xCuxF19?x with 0 ≤ x ≤ 1. 相似文献
10.
Mohamed Ali Saada Annie Hémon-Ribaud Vincent Maisonneuve 《Journal of fluorine chemistry》2005,126(7):1072-1077
Tren amine cations [(C2H4NH3)3N]3+ and zirconate or tantalate anions adopt a ternary symmetry in two hydrates, [H3tren]2·(ZrF7)2·9H2O and [H3tren]6·(ZrF7)2·(TaOF6)4·3H2O, which crystallise in R32 space group with aH = 8.871 (2) Å, cH = 38.16 (1) Å and aH = 8.758 (2) Å, cH = 30.112 (9) Å, respectively. Similar [H3tren]2·(MX7)2·H2O (M = Zr, Ta; X = F, O) sheets are found in both structures; they are separated by a water layer (Ow(2)-Ow(3)) in [H3tren]2·(ZrF7)2·9H2O. Dehydration of [H3tren]2·(ZrF7)2·9H2O starts at room temperature and ends at 90 °C to give [H3tren]2·(ZrF7)2·H2O. [H3tren]2·(ZrF7)2·H2O layers remain probably unchanged during this dehydration and the existence of one intermediate [H3tren]2·(ZrF7)2·3H2O hydrate is assumed. Ow(1) molecules are tightly hydrogen bonded with -NH3+ groups and decomposition of [H3tren]2·(ZrF7)2·H2O occurs from 210 °C to 500 °C to give successively [H3tren]2·(ZrF6)·(Zr2F12) (285 °C), an intermediate unknown phase (320 °C) and ZrF4. 相似文献