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Samia Yahyaoui Rached Ben Hassen Bruno Donnadieu Jean‐Claude Daran Abdelhamid Ben Salah 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):i109-i111
The title compound, namely octaaquaytterbium(III) aquanonachlorotricadmate(II) hexahydrate, [Yb(H2O)8][Cd3Cl9(H2O)]·6H2O, was prepared by evaporation at 278 K from an aqueous solution of the ternary system YbCl3–CdCl2–H2O and was characterized by elemental chemical analysis and by X‐ray powder and single‐crystal diffraction studies. The crystal structure can be viewed as being built from layers of double chains of CdCl6 and CdCl5(H2O) octahedra separated by antiprismatic [Yb(H2O)8]3+ cations. The stabilization of the structure is ensured by O—H⋯O and O—H⋯Cl hydrogen bonds. A comparison with the structures of SrCd2Cl6·8H2O and CeCd4Cl11·13H2O is presented. 相似文献
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Wang‐Ting Wu Feng‐Ying Chen Shui‐Yang He Huai‐Ming Hu Meng‐Lin Yang Yao‐Yu Wang 《中国化学》2006,24(5):711-713
The binuclear praseodymium(III) complex with N‐(1‐carboxyethylidene)‐salicylhydrazide (C10H10N2O4, H2L) was prepared in H2O‐C2H5OH mixed solution, and the crystal structure of [Pr2L2(HL)2(H2O)4]·3H2O·C6H6 was determined by X‐ray single crystal diffraction. The crystal complex crystallizes in the triclinic system with space group P‐1, and in the structure each Pr atom is 9‐coordinated by carboxyl O and acyl O and azomethine N atoms of two tridentate ligands to form two stable five‐membered rings sharing one side in keto‐mode and two water molecules. The coordination polyhedron around Pr3+ was described as a monocapped square antiprism geometry. In an individual molecule, four tridentate ligands were coordinated by two negative univalent (HL) and two bivalent forms (L) respectively. Two negative univalent ligands were coordinated via μ2‐bridging mode. 相似文献
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Qualitative rules governing carbon and bridge-hydrogen placement permit the prediction of the most stable isomeric structures for the various carboranes. Seventy-three isomeric boron hydride and carborane structures, from B(6)H(9)(-) to C(4)B(2)H(6), were computed at the ab initio MP2(fc)/6-31G level to determine their relative stabilities quantitatively. Specific architectural features, recognized to be unfavorable, were assigned "energy penalty" values that allow the projection of comprehensive thermodynamic stability values via a simple additivity procedure. These values match the ab initio results with surprising precision. Our study includes Siebert's nido-2,3,5-C(3)B(3)H(7) and Wrackmeyer's nido-2,4-C(2)B(4)H(8) nido-6 carboranes, which contain "unusual" CH-B-bridge hydrogens. 相似文献
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Reaction of anhydrous ytterbium trichlorides with 2 equiv.of cyclopentylindenyl lithium in THF solution,followed by removal of the solvent and crystallization of the porduct from diethyl ether,affords a crystal complex of the composition(C5H9C9H6)2Yb(μ-Cl)2Li(Et2O)2.Crystallographic analysis shows that the ytterbium coordinated by two cyclopentylindenly rings and lithium surrounded by two ether molecules are bridged by the two chlorine atoms and Yb,Li and two chlorine atoms form a plane. 相似文献
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无水YCl3与1-环戊烷基茚基锂以1/2的摩尔比在THF中反应合成了二(1-环戊烷基茚基)氯化钇(C5H9C9H6)2Y(μ-Cl)2Li(THF)2,产物用元素分析、红外光谱及XRD进行表征. 结果表明,其晶体属于正交晶系,Pna2(1)空间群,a =1.648 2(7) nm,b =1.877 2(8) nm,c =1.131 7(5) nm,V =3.501(3) nm3,Z=4,Dc=1.285 Mg/m3,最终的偏离因子R=0.068 3,Rw=0.114 3. 相似文献
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N. Boudjada 《无机化学与普通化学杂志》1981,477(6):225-228
Te(OH)6 · 2Na3P3O9 · 6H2O, is hexagonal (P63/m) with a = 11,67(1), c = 12,12(1) Å, Z = 2 and Dx = 2,225 g/cm3. Te(OH)6 · K3P3O9 · 2H2O, is monoklin (P21/c) with a = 19,61(5), b = 7,456(1), c = 14,84(6) Å, = 108,01(4), Z = 4 and Dx = 2,506 g/cm3. Both compounds are the first examples of phosphate tellurates in which the anion phosphate is condensed to the ring anion P3O9. As in phosphate tellurates already described the phosphate groups are independent of the TeO6 octahedra. 相似文献
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The first crystal structural report of a AgDTC complex (DTC-dialkyldithiocarbamate,R=n-butyl)presented in this paper shows that it is a hexanuclear species.The structural arrangement for the DDP(dialkyldithiophosphate)ligands is different from that of Cu6(DDP)6,but is the same as that of Ag6-[SSP(O-i-Pr)2]6. 相似文献
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Pierre-Franois Deschenaux Thomas Kallimopoulos Helen Stoeckli-Evans Andr Jacot-Guillarmod 《Helvetica chimica acta》1989,72(4):731-737
Enantiospecific Synthesis of (+)-(2R)- and (?)-(2S)-6-Ethyl-3,4-dihydro-2-methyl-4-oxo-2H-pyran-5-carboxylic Acid The two enantiomers (?)-(2S)- and (+)-(2R)-6-ethyl-3,4-dihydro-2-methyl-4-oxo-2H-pyran-5-carboxylic acid ((S)- and (R)- 7 ) have been synthesized from (+)-(3S) and (?)-(3R)-3-hydroxybutanoates, respectively (Scheme 1). By reduction and decarboxylation, the tetrahydro-2H-pyranols (2R, 4R, 6S)- and (2S, 4S, 6R)- 13 , respectively, were obtained with an enantiomeric excess of ≥ 93%. 相似文献
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McKee ML 《Inorganic chemistry》2001,40(22):5612-5619
Two pathways have been considered in the fluorination of CB(5)H(6)(-) and CB(9)H(10)(-) by HF. In the ionic HF fluorination pathway, the monocarborane anion cage is first protonated in a BBB face followed by H(2) elimination and fluoride anion addition. In the covalent HF fluorination pathway, HF is first coordinated through hydrogen to the BBB face. Next, the fluorine can add to either an axial or equatorial boron atom which opens the cage to a nido structure with an endo fluoride substituent. Endo to exo rearrangement occurs with a small activation barrier followed by H(2) elimination. In both pathways, fluorination at the equatorial boron position is predicted to have smaller activation barriers even though substitution at the axial position leads to the more stable products. 相似文献
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Nonasodium Bis(hexahydroxoaluminate) Trihydroxide Hexahydrate (Na9[Al(OH)6]2(OH)3 · 6H2O) – Crystal Structure, NMR Spectroscopy and Thermal Behaviour The crystal structure of the nonasodium bis(hexahydroxoaluminate) trihydroxide hexahydrate Na9[Al(OH)6]2(OH)3 · 6H2O (4.5 Na2O Al2O3 · 13.5 H2O) (up to now described as 3 Na2O · Al2O3 · 6H2O, 4Na2O · Al2O3 · 13 H2O and [3 Na2O · Al2O3 · 6H2O] [xNaOH · yH2O], respectively) was solved. The X-ray single crystal diffraction analysis (triclinic, space group P1 , a = 8.694(1) Å, b = 11.344(2) Å, c = 11.636(3) Å, α = 74.29(2)°, β = 87.43(2)°, γ = 70.66(2)°, Z = 2) results in a structure, consisting of monomeric [Al(OH)6]3? aluminate anions, which are connected by NaO6 octahedra groups. Furthermore the structure contains both, two hydroxide anions only surrounded by water of crystallization and OH groups of [Al(OH)6]3? aluminate anions and a hydroxide anion involved in three NaO6 coordination octahedra directly and moreover connected with a water molecule by hydrogen bonding. The results of 27Al and 23Na-MAS-NMR investigations, the thermal behaviour of the compound and possible relations between the crystal structure and the conditions of coordination in the corresponding sodium aluminate solution are discussed as well. 相似文献
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Reactions of a freshly prepared Zn(OH)2‐2x(CO3)x · yH2O precipitate, phenanthroline with azelaic and sebacic acid in CH3OH/H2O afforded [Zn(phen)(C9H15O4)2] ( 1 ) and [Zn2(phen)2(H2O)2(C10H16O4)2] · 3H2O ( 2 ), respectively. They were structurally characterized by X‐ray diffraction methods. Compound 1 consists of complex molecules [Zn(phen)(C9H15O4)2] in which the Zn atoms are tetrahedrally coordinated by two N atoms of one phen ligand and two O atoms of different monodentate hydrogen azelaato groups. Intermolecular C(alkyl)‐H···π interactions and the intermolecular C(aryl)‐H···O and O‐H···O hydrogen bonds are responsible for the supramolecular assembly of the [Zn(phen)(C9H15O4)2] complexes. Compound 2 is built up from crystal H2O molecules and the centrosymmetric binuclear [Zn2(phen)2(H2O)2(C10H16O4)2] complex, in which two [Zn(phen)(H2O)]2+ moieties are bridged by two sebacato ligands. Through the intermolecular C(alkyl)‐H···O hydrogen bonds and π‐π stacking interactions, the binuclear complex molecules are assembled into layers, between which the lattice H2O molecules are sandwiched. Crystal data: ( 1 ) C2/c (no. 15), a = 13.887(2), b = 9.790(2), c = 22.887(3)Å, β = 107.05(1)°, U = 2974.8(8)Å3, Z = 4; ( 2 ) P1¯ (no. 2), a = 8.414(1), b = 10.679(1), c = 14.076(2)Å, α = 106.52(1)°, β = 91.56(1)°, γ = 99.09(1)°, U = 1193.9(2)Å3, Z = 1. 相似文献