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1.
Vítězslav Zima Jan Svoboda Klára Melánová Ji?í Dybal 《Journal of solid state chemistry》2007,180(3):929-939
Several new strontium 4-carboxyphenylphosphonates, i.e., two modifications of Sr(HOOCC6H4PO3H)2, SrH(OOCC6H4PO3)·H2O, Sr3(OOCC6H4PO3)2·4H2O and Sr3(OOCC6H4PO3)2·5.7H2O were prepared and characterized by elemental analysis, thermogravimetry, X-ray powder diffraction and infrared spectroscopy. It was found that the compositions of these compounds depend on the acidity of the reaction medium. In addition, the presented compounds are interconvertible in dependence on pH. The position of the acid hydrogen atom in SrH(OOCC6H4PO3)·H2O was determined from the IR spectra of the studied compounds.The structure of the β modification of Sr(HOOCC6H4PO3H)2 was solved from its X-ray powder diffraction pattern using an ab initio method (the FOX program) with subsequent Rietveld refinement in the FULLPROF program. The compound is monoclinic, with the space group P21/c (No. 14), a=49.88(2), b=7.867(2), c=5.602(3) Å, β=128.68(2)°, and Z=4. It has a one-dimensional structure with an inorganic part built of SrO8 distorted tetragonal antiprisms. 相似文献
2.
Falko M. Schappacher Rainer Pöttgen 《Monatshefte für Chemie / Chemical Monthly》2008,139(10):1137-1142
The rare earth-rich cadmium compounds RE 4 TCd (RE = Y, La–Nd, Sm, and Gd–Tm, Lu; T = Co, Ru, and Rh) were prepared from the elements in sealed tantalum ampoules in an induction furnace. All samples were characterized by X-ray powder diffraction. The structures of Y4RuCd (a = 1362.5(1) pm), La4RuCd (a = 1415.9(1) pm), Gd4RuCd (a = 1368.8(2) pm), La4CoCd (a = 1417.9(4) pm), Gd4CoCd (a = 1356.1(1) pm), and Gd4RhCd (a = 1368.7(1) pm) were refined from single crystal X-ray diffractometer data. The RE 4 TCd compounds crystallize with the cubic Gd4RhIn type structure, space group F ${\bar 4}The rare earth-rich cadmium compounds RE
4
TCd (RE = Y, La–Nd, Sm, and Gd–Tm, Lu; T = Co, Ru, and Rh) were prepared from the elements in sealed tantalum ampoules in an induction furnace. All samples were characterized
by X-ray powder diffraction. The structures of Y4RuCd (a = 1362.5(1) pm), La4RuCd (a = 1415.9(1) pm), Gd4RuCd (a = 1368.8(2) pm), La4CoCd (a = 1417.9(4) pm), Gd4CoCd (a = 1356.1(1) pm), and Gd4RhCd (a = 1368.7(1) pm) were refined from single crystal X-ray diffractometer data. The RE
4
TCd compounds crystallize with the cubic Gd4RhIn type structure, space group F
3m. The transition metal atoms have tricapped trigonal prismatic rare earth coordination. The trigonal prisms are condensed
via common edges, forming a rigid three-dimensional network with adamantane symmetry. Voids in these networks are filled by Cd4 tetrahedra (304 pm Cd–Cd in Gd4CoCd) and polyhedra of the RE1 atoms. The crystal chemical peculiarities are briefly discussed.
Correspondence: Rainer P?ttgen, Institut für Anorganische und Analytische Chemie, Westf?lische Wilhelms-Universit?t Münster,
Correnstrasse 30, 48149 Münster, Germany. 相似文献
3.
Oleg KasyanDariusz Swierczynski Andrew DrapailoKinga Suwinska Janusz LipkowskiVitaly Kalchenko 《Tetrahedron letters》2003,44(38):7167-7170
The synthesis and structure of new tetrahydroxythiacalix[4]arenes, existing in the cone conformation and possessing reactive bromide, chloromethyl or diorganylphosphoryl groups on the upper rim of the macrocycle are described. The molecular structure of tetrakis(diisopropoxyphosphorylmethyl)thiacalix[4]arene was examined by X-ray crystallography. 相似文献
4.
P. Praveen Kumar Y. Dathu ReddyCh. Venkata Ramana Reddy B. Rama DeviP.K. Dubey 《Tetrahedron letters》2014
Green and efficient one pot, three-component synthesis of novel 2-amino-6-(1,4-dioxo-3,4-dihydrophthalazin)-2(1H)-yl-4-phenyl-4H-pyran-3,5-dicarbonitriles 6 has been developed by condensing 3-(1,4-dioxo-3,4-dihydrophthalazin-(1H)-yl)-3-oxopropanenitrile 3, benzaldehydes 4 and active methylene compounds 5 using l-proline as catalyst in EtOH at RT. 相似文献
5.
Chuqiao Tu 《Tetrahedron》2007,63(19):4184-4189
Di-ionizable calix[4]arene-1,2-crown-4 ethers in the cone conformation were synthesized and their conformation and regioselectivity verified by NMR spectroscopy. These new ligands exhibited high Ba2+ selectivity in competitive solvent extraction of alkaline earth metal cations from aqueous solutions into chloroform. The selectivity order was Ba2+>>Sr2+>Ca2+>Mg2+ with Ba2+/Sr2+ selectivity exceeding 100. The ligands also exhibited high extraction ability for Pb2+ and for Hg2+ in single species extraction. With variation of proton-ionizable groups, which are oxyacetic acid moieties and N-(X)sulfonyl oxyacetamide units with X=methyl, phenyl, 4-nitrophenyl, and trifluoromethyl, ‘tunable’ ligand acidity was obtained. 相似文献
6.
The reaction of alkylation of cis- and trans-4-fluoro-N-Boc-l-proline methyl esters has been examined by exposing their lithium enolates to a range of alkylating agents. The process showed a high degree of facial diastereoselectivity (except when methyl iodide was used as alkylating agent), invariably giving rise to products bearing the alkyl group in anti with respect to the fluorine atom. A tentative model to account for the observed stereoselectivity is also proposed. 相似文献
7.
Viktor Hlukhyy 《Journal of solid state chemistry》2005,178(1):79-84
Phase analytical investigations in the system magnesium-iridium-indium revealed the magnesium-rich intermetallics Ir3.30(1)Mg17.96(4)In0.74(4) and Ir3Mg17.1(1)In1.9(1). The samples were prepared from the elements via induction melting in glassy carbon crucibles in a water-cooled sample chamber and subsequent annealing. Both intermetallics were investigated by X-ray powder and single-crystal diffraction: C2/c, Z=4, a=979.1(1), b=2197.4(2), , β=105.79(1)°, wR2=0.0434, 3076 F2 values, 108 variables for Ir3.30(1)Mg17.96(4)In0.74(4), and a=983.39(8), b=2211.4(2), , β=105.757(6)°, wR2=0.0487, 3893 F2 values, and 115 variables for Ir3Mg17.1(1)In1.9(1). Both compounds show solid solutions. In Ir3.30(1)Mg17.96(4)In0.74(4), the indium site shows an occupancy by 69.9(4)% In+30.1(4)% Ir, and one magnesium site has a small mixed occupancy with indium, while nine atomic sites in Ir3Mg17.1(1)In1.9(1) show Mg/In mixing with indium occupancies between 1.2(3)% and 14.8(3)%. The relatively complex crystal structure is of a new type. It can be explained by a packing of coordination number 10 and 12 polyhedra around the iridium atoms. The crystal chemical peculiarities and chemical bonding in both intermetallics is briefly discussed. 相似文献
8.
Jun-Ho Kim 《Journal of solid state chemistry》2008,181(8):2108-2112
Two new tellurites, NH4RbTe4O9·2H2O and NH4CsTe4O9·2H2O have been synthesized and characterized. The compounds were synthesized hydrothermally, in near quantitative yields, using the alkali metal halide, TeO2, and NH4OH as reagents. The iso-structural materials exhibit layered, two-dimensional structural topologies consisting of TeOx (x=3, 4, or 5) polyhedra separated by NH4+, H2O, Rb+ or Cs+ cations. Unique to these materials is the presence of TeO3, TeO4, and TeO5 polyhedra. Thermogravimetric and infrared spectroscopic data are also presented. Crystal data: NH4RbTe4O9·2H2O: Monoclinic I2/a (no. 15), a=18.917(3) Å, b=6.7002(11) Å, c=21.106(5) Å, β=101.813(2)°, V=2618.5(9) Å3, Z=8; NH4CsTe4O9·2H2O: Monoclinic I2/a (no. 15), a=18.9880(12) Å, b=6.7633(4) Å, c=21.476(2) Å, β=102.3460(10)°, V=2694.2(3) Å3, Z=8. 相似文献
9.
Tat'yana T Kucherenko Roman Gutsul Vladimir M Kisel Vladimir A Kovtunenko 《Tetrahedron》2004,60(1):211-217
Previously unknown 3-arylamino-1,2-dihydro-1-isoquinolones were obtained by condensation of 2-cyanomethylbenzoic acid with arylamines. Isonicotinoylation of the compounds was shown to proceed at the carbon atom in the 4-position to give 3-arylamino-4-isonicotinoyl-1,2-dihydro-1-isoquinolones which were quaternized with alkylating agents and formed the corresponding pyridinium salts. Deprotonation of the latter induced intramolecular conjugated addition with the pyrrole ring closure and formation of spiro compounds. The structure of the products was confirmed by NMR, IR and UV spectroscopy and by synthesis of the model compound, 3-(4-tolyl)-2,3,4,5-tetrahydro-1H-pyrrolo[2,3-c]isoquinoline-1,5-dione. 相似文献
10.
We have synthesized a new compound with formula Re4As6S3 and characterized its crystal structure by Rietveld powder diffraction methods. Re4As6S3 crystallizes in an face-centered cubic unit cell, space group (no. 216), with lattice constant a=9.8608(1) Å and Z=4. The rhenium atoms form tetrahedral clusters linked via tetrahedral arsenic clusters to produce an NaCl-type arrangement. The oxidation state of rhenium is IV and the number of electrons shared by the rhenium atoms in the cluster is 12. The structure is based on an ordered defect thio-spinel A(1−x)B2X4 where the B-type atoms form tetrahedral clusters. 相似文献
11.
A series of calix[4]arenes bearing various substituents including alkyl, p-bromobenzyl, carboxy and allyl at opposite methylene bridges has been synthesized via successive metallation followed by nucleophilic substitution. In a first step, mono-lithiated calix[4]arenes react with terminal bromoalkanes to give 2-alkylated calix[4]arenes or with CO2 the respective calixarene-2-carboxylic acid in good yields. A second lithiation step of the monosubstituted products with subsequent attachment of both polar and non-polar substituents yields several new diametrally bridge-disubstituted calix[4]arenes. 2D-NMR measurements establish the disubstituted calixarenes to predominantly adopt the 1,2-alternate conformation in solution. First examples of X-ray crystal structures of the new type of disubstituted calix[4]arenes are described featuring the calix[4]arene also in the rare 1,2-alternate conformation. 相似文献
12.
Anatoliy M ShestopalovYuliya M Emeliyanova Aleksandr A ShestopalovLyudmila A Rodinovskaya Zukhra I NiazimbetovaDennis H Evans 《Tetrahedron》2003,59(38):7491-7496
To develop a method of synthesis of the potentially physiologically active compounds, 1′-substituted 6-amino-spiro-4-(piperidine-4′)-2H,4H-pyrano[2,3-c]pyrazoles, we studied the three-component condensation of substituted piperidin-4-ones, malononitrile and pyrazolin-5-ones. It was found that the electrochemical method of synthesis is more regioselective, the products of the reaction are analytically pure and do not require further recrystallization. 相似文献
13.
E. Bernhardt 《Journal of fluorine chemistry》2004,125(6):967-973
First examples for the syntheses of trifluoromethyl transition metal complexes by conversion of a cyano into a trifluoromethyl ligand are described. The fluorination of [][Au(CN)4] with ClF in CH2Cl2 leads to the formation of a mixture of gold complexes of the type [AuFxCly(CF3)4−x−y]− (x=0-4, y=0-2). Ligand exchange reactions of [AuFxCly(CF3)4−x−y]− (x=0-4, y=0-2) with (CH3)3SiY (Y=Cl, CN) are performed resulting in anions of the type [AuYx(CF3)4−x]− (x=0-4). All products are characterised by - and NMR spectroscopy. 相似文献
14.
Michela Lupi Martina Onori Stefano Menichetti Sergio Abbate Giovanna Longhi Caterina Viglianisi 《Molecules (Basel, Switzerland)》2022,27(4)
We have developed an efficient chemical resolution of racemic hydroxy substituted dithia-aza[4]helicenes (DTA[4]H) 1(OH) using enantiopure acids as resolving agents. The better diastereomeric separation was achieved on esters prepared with (1S)-(−)-camphanic acid. Subsequent simple manipulations produced highly optically pure (≥ 99% enantiomeric excess) (P) and (M)-1(OH) in good yields. The role of the position where the chiral auxiliary is inserted (cape- vs. bay-zone) and the structure of the enantiopure acid used on successful resolution are discussed. 相似文献
15.
Hyunjin Bang 《Journal of solid state chemistry》2008,181(8):1798-1802
We found new synthetic routes to obtain 1-D quaternary thiophosphate compounds and a 0-D molecular complex containing a Nb2S4 core from a 2-D ternary thiophosphate, Nb4P2S21. When Nb4P2S21 was reacted with alkali metal halides (ACl; A=Na, K, Rb, Cs) or TlCl at 500-700 °C, the -S-S-S- bridges in 2-D Nb2PS10-S-S10PNb2 were excised to form a 1-D chain, and cations were inserted between the chains to form ANb2PS10 (A=Na, K, Rb, Cs, Tl). We also found that thallium chloride (TlCl) is an excellent reagent for further excision, and it substitutes chloride ligands for the sulfur ligands of 2-D Nb4P2S21 to form the molecular complex Tl5[Nb2S4Cl8]Cl. Crystal data for TlNb2PS10: monoclinic, Pn, a=6.9452(11) Å, b=7.3761(12) Å, 12.873(2) Å, β=104.472(3)°, and Z=2. Crystal data for Tl5[Nb2S4Cl8]Cl: orthorhombic, Immm, a=7.001(5) Å, b=9.509(7) Å, c=15.546(11) Å, and Z=2. 相似文献
16.
17.
Theresa Komm 《Journal of solid state chemistry》2005,178(2):454-463
The two non-isotypical rubidium rare-earth(III) thiophosphates Rb3M3[PS4]4 of praseodymium and erbium can easily be obtained by the stoichiometric reaction of the respective rare-earth metal, red phosphorus and sulfur with an excess of rubidium bromide (RbBr) as flux and rubidium source at 950°C for 14 days in evacuated silica tubes. The pale green platelet-shaped single crystals of Rb3Pr3[PS4]4 as well as the pink rods of Rb3Er3[PS4]4 are moisture sensitive. Rb3Pr3[PS4]4 crystallizes triclinically in the space group (, , , α=84.329(4)°, β=88.008(4)°, γ=80.704(4)°; Z=2), Rb3Er3[PS4]4 monoclinically in the space group P21/n (, , , β=95.601(6)°; Z=4). In both structures, there are three crystallographically different rare-earth cations present. (M1)3+ is eightfold coordinated in the shape of a square antiprism, (M2)3+ and (M3)3+ are both surrounded by eight sulfur atoms as bicapped trigonal prisms each with a coordination number of eight as well as for the praseodymium, but better described as CN=7+1 in the case of the erbium compound. These [MS8]13− polyhedra form a layer according to by sharing edges with the isolated [PS4]3− tetrahedra (d(P-S)=200-209 pm, ?(S-P-S)=102-116°). These layers are stacked with a repetition period of three in the case of the praseodymium compound, but of only two for the erbium analog. The rubidium cation (Rb1)+ is located in cavities of these layers and tenfold coordinated in the shape of a tetracapped trigonal antiprism. The also tenfold but more irregularly coordinated rubidium cations (Rb2)+ and (Rb3)+ reside between the layers. 相似文献
18.
《Mendeleev Communications》2023,33(2):264-266
The polycrystalline samples of Cu2 – δSrSnS4 with a trigonal structure were prepared by solid-phase ampoule synthesis with a long annealing time (1944 h), and their crystal lattice parameters were refined and Raman spectra were obtained. For the first time, the effect of defect structure on the lifetimes of photogenerated current carriers in the polycrystalline powders was examined by combining time-resolved microwave photoconductivity and cathodoluminescence methods. A significant increase in the lifetimes during the conversion of Cu2SrSnS4 into Cu1.9SrSnS4 was found, which was probably due to changes in the defect structure. 相似文献
19.
The Rh2(OAc)4 catalyzed [3+2] cycloaddition of 4-diazo-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5(4H)-one with aromatic alkynes was studied, and this protocol can be efficiently applied to the synthesis of the novel CF3-substituted ring-fused furo[2,3-c]pyrazoles. 相似文献
20.
Mixed crystals of Li[Kx(NH4)1−x]SO4 have been obtained by evaporation from aqueous solution at 313 K using different molar ratios of mixtures of LiKSO4 and LiNH4SO4. The crystals were characterized by Raman scattering and single-crystal and powder X-ray diffraction. Two types of compound were obtained: Li[Kx(NH4)1−x]SO4 with x?0.94 and Li2KNH4(SO4)2. Different phases of Li[Kx(NH4)1−x]SO4 were yielded according to the molar ratio used in the preparation. The first phase is isostructural to the room-temperature phase of LiKSO4. The second phase is the enantiomorph of the first, which is not observed in pure LiKSO4, and the last is a disordered phase, which was also observed in LiKSO4, and can be assumed as a mixture of domains of two preceding phases. In the second type of compound with formula Li2KNH4(SO4)2, the room-temperature phase is hexagonal, symmetry space group P63 with cell-volume nine times that of LiKSO4. In this phase, some cavities are occupied by K+ ions only, and others are occupied by either K+ or NH4+ at random. Thermal analyses of both types of compounds were performed by DSC, ATD, TG and powder X-ray diffraction. The phase transition temperatures for Li[Kx(NH4)1−x]SO4x?0.94 were affected by the random presence of the ammonium ion in this disordered system. The high-temperature phase of Li2KNH4(SO4)2 is also hexagonal, space group P63/mmc with the cell a-parameter double that of LiKSO4. The phase transition is at 471.9 K. 相似文献