Synthese und Kristallstruktur von Hydronium-tris-ethylendiamin-cobalt(rhodium)-μ-trichloro-nonachlorotrirhenat(II)-chlorid,H3O[MEn3][Re3Cl12]Cl (M=Co,Rh)

Synthesis and Crystal Structure of Hydronium-tris-ethylenediamine-cobalt(rhodium)-μ-trichloro-nonachlorotrirhenate(III)-chloride, H₃O[MEn₃][Re₃Cl₁₂]Cl (M=Co, Rh) The chlorides H₃O[MEn₃][Re₃Cl₁₂]CI (M = Co, 1 ; Rh, 2 ) crystallize from hydrochloric acid solutions of ReCl₃ and MEn₃ · 3H₂O as deep red hexagonal columns. They are isotypic and crystallize with the hexagonal system (P6 , Z = 1; 1: a = 1010.87(3); c = 794.30(4) pm, R = 0.023, R_w = 0.016; 2: a = 1018.58(3); c = 794.74(4) pm, R = 0.026, R_w = 0.018). The anions [Re₃Cl₁₂]^3? are connected via H₃O₊ cation (C.N. 3). The large channels that run in the [001] direction contain, alternatively, the cations [MEn₃]³⁺ and the lonesome Cl^?-anions     

Darstellung und Kristallstruktur von LnAl3Br12 (Ln = La,Ce, Pr,Nd, Sm,Gd) und thermischer Abbau zu LnBr3

Preparation and Crystal Structure of LnAl₃Br₁₂ (Ln = La, Ce, Pr, Nd, Sm, Gd) and Thermal Decomposition to LnBr₃ LnAl₃Br₁₂ (Ln = La, Ce, Pr, Nd, Sm, Gd) was prepared in crystalline form for the first time. The crystal structures of LaAl₃Br₁₂, PrAl₃Br₁₂, and NdAl₃Br₁₂ were determined on single crystals by X-ray methods. The isotypic compounds crystallize with trigonal symmetry, space group P 3₁12, Z = 3. A structural comparison to lanthanoide chloroaluminates of equal composition is given and thermal decomposition of LnAl₃Br₁₂ (Ln = Nd) to the corresponding lanthanoide tribromide is described.     

Structural Characterization of the Chiral Skeleton Cluster RuCoMo (Co)_8(μ_3-Se ) C_5H_4C (O) C_6H_4C (O)OCH_3

1INTRoDUCTIoNIntenseinterestintransition-metalclusterscontinuesbecausetheyrepresentpos-sibleconceptualbridgesbetweenhomogeneousandheterogeneouscatalystsmoreoveralsobecausetheyrepresentsyntheticchallenges.TheuseofelementsofGroup16ofthePeriodicTableassingleatomligandsforclustergrowthandstabilizationofthemetalcorearenowwellestablished[1i.ThereisanincreasinginterestintheuseofSe-bridgrdclusters,manyofthereactionsofSe2Fe2(CO),andSe2Fe,(CO),havebeenreported"';however,therehasbeenverylittlewor…     

Synthesis and structure of neutral π-arene complex (η6-C6H5Me)U(AlCl4)3

A new neutral -arene complex of trivalent uranium, (⁶-C₆H₅Me)U(AlCl₄)₃ (1), was obtained by the reductive Freidel-Crafts reaction. The crystal structure of 1 was determined by single crystal X-ray diffraction analysis. The U atom in 1 is bound to the C₆H₅Me group by the ⁶ mechanism and is linked to the three AICl₄ groups through two g-CI bridges. The coordination of the U atom is a distorted pentagonal bipyramid in which the center of the arene ring is in one apical position, and the bridging Cl atoms occupy the other vertices.Translated from Izvestiva Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 469–472, February, 1996.     

Syntheses and structural characterizations of Fe_4S_4 cubane-like cluster compounds containing cycloalkylthiolate ligands

In a reaction system consisting of FeCl2,tetrathiometallate and cycloalkylthiolate,two Fe4S4 cubane-like cluster compounds were obtained with the following crystallographic data:(PhCH2NMe32[Fe4S4 (SC5H9)4](Ⅰ),monoclinic space group P21/c,a=1.6327(4),6=1.1229(3),c=2.802 5( 10) nm,β=94.63(2)°,Z=4,and R=0.074; (Et4N)2[Fe4S4(SC6H11)4](Ⅱ),tetragonal space group I42m,a=1.16705(9),b=1.167 06(2),c=2.063 26(5) nm,Z=2,Dabs=1.28 g/cm3,and R=0.078 The participation of cy-cloalkylthiolate ligand does not obviously arouse the change of the Fe4S4 core structure.Meanwhile,the influence of the cation on the structural symmetry of the Fe4S4 cluster dianion is also discussed.     

Hydrogen bonding in 2-hydroxy-benzhydrazide and 2-hydroxy-thiobenzhydrazide. Structural and spectroscopic study

Summary X-ray structural data are reported for 2-hydroxy-benzhydrazide(monoclinic; P2₁/n-C _2h ⁵ ;a=10.569(2) Å,b=11.264(2) Å,c=6.074(1) Å, =98.80(1)°;Z=4;R=0.054) and 2-hydroxy-thiobenzhydrazide (monoclinic; P2₁/n-C _2h ⁵ ;a=14.598(6) Å,b=5.975(2) Å,c=9.286(4) Å, =107.80(3)°;Z=4;R=0.044). In both compounds the phenolic OH groups are intramolecularly hydrogen bonded to the (thio)carbonyl oxygens and sulfurs, respectively; the basic intermolecular association patterns consist of closed six-membered hydrogen bonded dimers which are connected via N-H ... NH₂ hydrogen bonds. The spectral characteristics of the intramolecular O-H...O/S hydrogen bonds (solid state (OH)=2800/2700 cm^–1, CCl₄ solution (OH)=3035/3100 cm^–1, CDCl₃ solution (OH)=11.62/10.56 ppm) are similar to those of corresponding primary and secondary amides. The solid state IR spectra are consistent with hydrogen bonded NH groups and free NH₂ groups, the solution IR spectra indicate free NH₂ as well as free NH groups.

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Wasserstoffbrückenbindung in 2-Hydroxy-benzhydrazid und 2-Hydroxy-thiobenzhydrazid. Strukturelle und spektroskopische Untersuchungen

Zusammenfassung Es werden Röntgenstrukturdaten für 2-Hydroxy-benzhydrazid (monoklin; P2₁/n- C _2h ⁵ ;a=10.569(2) Å,b=11.264(2)Å,c=6.074(1)Å, =98.80(1)°;Z=4;R=0.054) und 2-Hydroxy-thiobenzhydrazid (monoklin; P2₁/n - C _2h ⁵ ;a=14.598(6)Å,b=5.975(2)Å,c=9.286(4)Å, =107.80(3)°;Z=4;R=0.044) berichtet. In beiden Verbindungen bilden die phenolischen OH-Gruppen intramolekulare Wasserstoffbrücken mit den Carbonyl-Sauerstoff-, bzw. den Thiocarbonyl-Schwefel-Atomen. Das intermolekulare Assoziationsmuster wird durch N-H...NH₂ Wasserstoffbrücken bestimmt, die jeweils zwei Moleküle über sechszählige Ringe zu Dimeren verbinden. Die IR- und NMR-spektroskopischen Charakteristika der intramolekularen O-H...O/S Wasserstoffbrücken (kristallin: (OH)=2800/2700 cm^–1, CCl₄-Lösungen: (OH)=3035/3100 cm^–1, CDCl₃-Lösungen: (OH)=11.62/10.56 ppm) sind sehr ähnlich zu denen entsprechender primärer und sekundärer Amide. Die Festkörper-IR-Spektren stehen in Einklang mit assoziierten NH- und freien NH₂-Gruppen, während die Lösungs-IR-Spektren auch auf das Vorliegen freier NH-Gruppen schließen lassen.

     

Ruthenium Cluster Chemistry with Ph2PC6H4-4-C≡CH

The new phosphines Ph₂PC₆H₄-4-CCR [R=SiMe₃ (1), H (2)] have been used to prepare Ru₃(CO)₉(Ph₂PC₆H₄-4-CCSiMe₃)₃ (4) and Ru(CCC₆H₄-4-PPh₂)(PPh₃)₂(-C₅H₅) (3), respectively, the latter with a pendent phosphine. Reaction of 4 with carbonate or fluoride affords Ru₃(CO)₉(Ph₂PC₆H₄-4-CCH)₃ (5) with pendent terminal alkynyl groups, the identity of which was confirmed by a structural study. Reaction of 5 with [Ru(NCMe)(PPh₃)₂(-C₅H₅)]PF₆ or reaction of Ru₃(CO)₁₂ with 3 gives Ru₃(CO)₉{(Ph₂PC₆H₄-4-CC)Ru(PPh₃)₂(-C₅H₅)}₃ (6). Complexes 3–6 have been studied by cyclic voltammetry. Proceeding from Ru₃(CO)₁₂ to 4 or 5 shifts the cluster-centred reduction to more negative potential and affords facile cluster-centred oxidation. Proceeding from 4/5 and 3 to 6 results in similarly-located cluster-centred reduction and peripheral ruthenium-centred oxidation, but results in a lack of observable cluster-centred oxidation. Crystal data for 5·C₆H₁₄: space group P¯1, a=12.760(1) Å, b=17.077(1) Å, c=17.924(2) Å, =108.656(5)°, =96.344(5)°, =93.523(5)°, V=3658.4(6) ų, Z=2, R=0.078, R_w=0.105 for 5008 reflections [I>2.00(I)].     

The Thermal Reaction of the Tris(μ-Hydrido)-Dodecacarbonyltrirhenium (o) Cluster with Triphenylphosphine and Triphenylphosphite

The thermal reaction between the tris(μ-hydrido)dodecacarbonyltrirhenium (o) cluster and triphenylphosphine or triphenylphosphite results in a trisubstituted rhenium cluster as the major product. The results of an X-ray structural analysis of H₃Re₂(CO)₉(PPh₃) are: Mr=1597.57, Monoclinic, P₂₁/n, a=15.598(1), b=9.530(2), c=41.685(3) Å, β=80.60(1)°, V=6113.(1) ų, Z=4, D_c=1.736 g/cm³, CuK_e, λ-1.54056 Å, μ-121.23 cm^?1, F(000)=3059.17, room temperature, R=0.049 for 7361 reflections with I≥2.5σ(I). The molecule has a triangular Re₂ core coordinated propellerwise by three PPh₃ ligands in the molecular plane with virtual C_3k symmetry.     

Synthesis and Crystal Structure of Bis(nitrate)- bis(N,N''''-dimethyl-N,N''''-dibenzenyl-urea)uranyl(Ⅱ)

1 INTRODUCTION Tri-butyl phosphate (TBP) has been widely used as the extraction reagent in U-Th fuel to separate uranium from thorium. But di-butyl phos- phate (DBP) and butyl phosphate (MBP), the radio- lytic products of TBP, exhibit some coordinated ability to the fission elements, such as Zr and Nb. The substitutes for TBP have being studied for several decades[1～4]. The physical and chemical properties of amides are similar to those of TBP and they selectively extract U(Ⅵ…     

Formation of sol-gel nanostructured mullite by additions of fluoride ion

Summary The subject of this study was to investigate the effect of fluoride ions addition on the temperature of sol gel mullite formation based on the hypotheses that the presence of fluoride ions can decrease the temperature of mullite formation (in respect to common 980°C, in sol-gel processing). Polymeric sols were prepared by mixing TEOS and aluminum nitrate nanohydrate and by adding fluoride ions (from 2 to 5 mass%). DTA, TG, XRD and SEM were used for characterisation of mullite gel and crystalline mullite. The experimental results confirmed that the addition of fluoride ions decrease the temperature of mullite formation up to 890°C for the fluorine concentration of 3.5 mass%. Experimental results showed that the temperature of mullite formation is not a simple function of the fluoride ion content. The mechanism of fluorine effect was discussed in terms of the gelling process, gel structure and the phase separation before the mullite formation.