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1.
19F NMR Spectroscopic Evidence and Calculation of the Statistical Formation of Mixed Cluster Anions [(Mo6Br Cl )F ]2?, n = 0 – 8 The complete system of the innersphere mixed clusters (Mo6BrCl)4+ is formed by exchange of innersphere bound Cli against outersphere bound Bra on tempering the solid [(Mo6Cl)Br] at 500°C for 16 h. After conversion with conc. HCl into (H3O)2[(Mo6BrCl)Cl] and precipitation of the outer Cla with AgBF4 in ethanol, treatment with tetrabutylammonium(TBA)fluoride yields (TBA)2 [(Mo6BrCl)F], a mixture of 22 different species. According to the sets of chemical equivalent fluorine atoms in total 55 19F nmr signals are expected, which are really observed in the high resolution 1D-19F-nmr spectrum. Using increments of chemical shifts, peak intensities and multiplet structures as well as the 2D-19F/19F-COSY spectrum the complete and unambiguous assignment of all resonances is achieved. From the measured integral intensities the distribution of the different compounds is determined, revealing statistical formation of the geometrical isomers.  相似文献   

2.
On Ordered Perovskites with Cationic Vacancies. XI. Compounds of Type A B B □1/4WVIO6 ? A BIIB □W O24 with AII, BII = Ba, Sr Depending on the ionic radii of the two and three valent cations in the perovskites of type ABB □1/4WVIO6 ?; ABIIB □WO24 order disorder phenomena are present. The results of the x-ray and vibrational spectroscopic investigations as well as the diffuse reflectance spectra and the visible photoluminescence are reported.  相似文献   

3.
Silaheterocycles. III. Synthesis and Reactivity of Di-tbutylneopentylsilaethene, Bu Si?CHCH2But The three di-tbutylvinylsilanes BuSi(X)CH?CH2 (X = H 5 , X = F 9 , X = Cl 22 ) are prepared by the reaction of their SiCl precursors with vinyl lithium. In the treatment with LiBut the first step is the generation of the α-lithio compound BuSi(X)CH(Li)CH2But, the following reactions are governed by the nature of the substituent X and the reaction conditions (solvent, concentration, temperature). For X = H 2,3-LiH elimination leads to BuSi(H)CH?CHBut ( 7 ), with X = F or Cl Si?C formation by 1,2-LiX elimination competes with intermolecular Si-C-coupling producing BuSi(H)CH(SiBuCH?CHBut)CH2But ( 13 ) as the main product. BuSi?CHCH2But ( 1 ) probably coordinates to LiBut and reacts to yield BuSiCH?CHBut ( 3 ) and 7 , forms tetrabutyl-dineopentyl-1,3-disilacyclobutane 2 by cyclodimerization and 13 by addition of BuSi(X)CH(Li)CH2But.  相似文献   

4.
19F NMR Spectroscopic Evidence and Calculation of the Statistical Formation of Mixed Cluster Anions [(Mo6I Cl )F ]2?, n = 0–7, and Preparation of (TBA)2[(Mo6I )F ] The octa-μ3-iodo-hexafluoro-hexamolybdate(2?)ion [(Mo6I)F]2? is prepared for the first time. The system of the 21 innersphere mixed clusters (Mo6ICl)4+, n = 0–7 is formed by exchange of innersphere bound Cli against outersphere bound Ia on tempering solid [(Mo6Cl)I] at 400°C. Prolonged tempering leads to increasing average n values of the mixture, which is converted into the tetrabutylammonium salt (TBA)2[(Mo6ICl)F]. Using increments of chemical shifts and integral peak intensities the 54 19F-nmr signals of the 21 species (compound n = 8 is absent) are assigned and confirmed by the 2 D-19F/19F-COSY spectrum. From the measured intensities the distribution of the different compounds is determined and proves significant deviation from statistical occupation, revealing the preference of isomers with iodine atoms occupying edges of the innersphere cube and discrimination of those sharing diagonals of the faces. Moreover all compounds with n = 3 and 4 are present overaverage in comparison to the others.  相似文献   

5.
On the Formation of Polysulphane Diphosphonates by the Reaction of Monothiophosphonate with Disulphane Diphosphonate In acid solution SPO reacts with S2P2O forming higher polysulphane diphosphonates. The formation of S3P2O and S4P2O is proved by evaluation of the double labelling with 35S? 32P after high paper electrophoresis.  相似文献   

6.
On the Crystal Structure of O MF (M = Sb, Ru, Pt, Au) OMF (M = Sb, Ru, Pt, Au) were obtained again, but for the first time investigated by X-ray methods. Colourless OSbF and the rubyred compounds ORuF and OPtF crystallize isostructural in space group Ia3 -Th7 (Nr. 206) with a = 1016(1) pm (Sb), a = 1002.6(9) pm (Ru) and a = 1003.6(9) pm (Pt), Z = 8. Yellow OAuF crystallizes trigonal-rhombohedric in space group R3 -D326 (Nr. 148) with a = 775.9(3) pm, c = 711.7(4) pm, Z = 3.  相似文献   

7.
Synthesis, Vibrational Spectra, and Crystal Structure of ( n ‐Bu4N)2[(W6Cl )F ] · 2 CH2Cl2 and 19F NMR Spectroscopic Evidence of the Mixed Cluster Anions [(W6Cl )F Cl ]2–, n = 1–6 The reaction of (n‐Bu4N)2[(W6Cl)Cl] with CF3COOH in dichloromethane gives intermediately a mixture of the cluster anions [(W6Cl)(CF3COO)Cl]2–, n = 1–6. By treatment with NH4F the outer sphere coordinated trifluoracetato ligands are easily substituted and the components of the series [(W6Cl)FCl], n = 1–6 are formed and characterized by their distinct 19F NMR chemical shifts. An X‐ray structure determination has been performed on a single crystal of (n‐Bu4N)2[(W6Cl)F] · 2 CH2Cl2 (orthorhombic, space group Pbca, a = 15.628(4), b = 17.656(3), c = 20.687(4) Å, Z = 4). The low temperatur IR (60 K) and Raman (20 K) spectra are assigned by normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constants are fd(WW) = 1.89, fd(WF) = 2.43 and fd(WCl) = 0.93 mdyn/Å.  相似文献   

8.
On Ordered Perovskites with Cationic Vacancies. X. Compounds of Type A B B □1/4MVIO6 ? A BIIB □M O24 with AII, BII = Ba, Sr, Ca and MVI = U, W Perovskites of type Ba8BIIB2III□UO24 show polymorphic phase transformations of order disorder type. An 1:1 ordered orthorhombic HT form is transformed into a higher ordered LT modification with a fourfold cell content (four formula units Ba8BIIB□U4O24), compared to cubic 1:1 ordered perovskites A2BMO6. In the series Ba8BaB□W4O24 and Sr8SrB□W4O24 different ordering phenomena are observed. In comparison with 1:1 ordered cubic perovskites A2BMO6, the cell contains eight formula units ABIIB□W4O24. The higher ordered cells with UVI and WVI are face centered, which has its origin in an ordering of cationic vacancies.  相似文献   

9.
Kinetic Calculations for the Formation of Chloro-Bromo-Iodo-Osmates(IV) Rate constants of formation and ligand exchange reactions of mixed hexahaloosmates(IV) of the type [OsClxBryI6?x?y]2?, x + y = 2?5, are computable taking into account the relative cis- (f = 1, f = 1.75, f ≈? 6) and trans-effects (f = 1, f = 6, f ≈? 103) of the ligands as well as statistic factors. Using this kinetic data concentration-time diagrams are calculated for reactions including several parallel and consecutive steps. They agree well with the experimentally determined distribution of products in the reaction mixtures. For the preparation of particular mixed ligand complexes the best way of synthesis and maximum yield can be precalculated.  相似文献   

10.
Preparation and Spectroscopic Characterization of the Cluster Anion [(Mo6Cl )(CF3COO) ]2? On heating of [(Mo6Cl)Cl]2? in dichloromethane with trifluoroacetic acid the new stable cluster anion [(Mo6Cl)(CF3COO)]2? is formed by elimination of HCl. The (Mo6Cl) unit remains unattacked. The 19F nmr spectrum exhibits a downfield shifted singulett as compared to free CF3COO? indicating the equivalence of all trifluoroacetate ligands, which unidentate coordination is deduced from characteristic i. r. frequencies of the carboxyl groups. The most intense i.r. band at 501 cm?1 is assigned to the antisymmetric Mo? Oa vibration, the most intense Raman line at 319 cm?1 to the breathing mode of the Cl cube.  相似文献   

11.
The preparation of MMoOSSe2 and MWOSSe2 (MI = Cs, Tl) is reported. The measured IR and electronic absorption spectra are discussed. It was found by X-ray studies that both cesium salts are crystallising in the space group D—Pnma with Z = 4 (For dimensions of the unit cell and density see Inhaltsübersicht).  相似文献   

12.
On Perovskites A B B WVIO6 Compounds of type ABBWVIO6 can be obtained with AII ? Ba; BI ? Li, Na and BIII ? La, Nd, Sm, Gd, Y, In, Sc just as with AII ? Sr, BI ? Li and BIII ? La, Nd, Sm, Gd, Y, In (all cubic ordered perovskites). For the cubic perovskites Sr2Na0,5La0,5WO6 and Sr2Na0,5Nd0,5WO6 additional superlattice reflections are observed (a ∽ 16.4 Å). The compounds Sr2Na0,5BWO6 crystallize with BIII ? Sm, Gd in a monoclinic and with BIII ? Y, In in a rhombic distorted perovskite lattice. For the perovskites with A = Sr — dependent on ionic radii of the B ions — two different lattice types are present.  相似文献   

13.
On Perovskites Ba2B B TeVIO6 Compounds of composition Ba2BBTeVIO6 with BI = Li, Na; BIII = La, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Yb, Y, In, Sc crystallize in a cubic 1:1 ordered perovskite structure. The vibrational spectroscopic investigations show, that more species of TeO6 octahedra are present in the lattice.  相似文献   

14.
Dibromomethylsulfoniumsalts — Preparation and Crystal Structure The salts CH3SBrA? (A? = SbCl, AsF) were prepared by various routes and characterized by their Ramanspectra. CH3SBrAsF crystallized in the monoclinic space group P21/c with a = 770,5(4) pm, b = 942,4(12) pm, c = 1329,3(14) pm, β = 100,28(6)°, Z = 4. Distances and bond angles in the cation are as expected.  相似文献   

15.
Reactions of dry THF/MeCN solutions of Ca[Re6SCl(Cla)6] with silylated derivatives E(SiMe3)2 (E = PhAs, PSiMe3, HN, O, S) and addition of trialkylphosphine PPr3 afford in high yields and at room temperature either the neutral clusters [Re6SX(PPr3)] ( 1 : X = As, 2 : X = P) or the ionic compounds [Re6SX(PPr3)]2+ · [Re6S6Cl8]2– ( 3 : X = NH, 4 : X = O, 5 : X = S). The compounds 1 – 5 were characterised by X‐ray crystal structure analysis. A di‐substitution reaction occurs on the {Re6SCl}4+ cluster core, where the two inner μ3‐chloro ligands Cli are substituted by X (X = As, P, NH, O, S) and all six terminal chloro ligands Cla are exchanged by terminal PPr3‐ligands.  相似文献   

16.
Magnetic interactions in some oxyfluoroferrites of spinel structure with the formula ZnxMe2?xO4?xFx (M = Fe, Co, Ni) Whereas the ferromagnetic spin arrangement of the B-cations is not modified by the Zn2+?Fe3+ substitution in the ZnFe[Fe2+Fe3+]O4?xFx (0 ≤ x ≤ 0,50) spinel, this same substitution leads to a spin canting in the ZnFe[Co2+Fe3+]O4?xFx and ZnFe[Ni2+Fe3+]O4?xFx (0 ≤ x ≤ 0,80) simples. The difference in the magnetic behaviors with regard to the AB and BB interactions can be explained on the basis of the magnetic exchange theory.  相似文献   

17.
On the Formation of Polysulphane Phosphonsulphonates by the Reaction of SPO with Polythionates and S2O with Disulphane Diphosphonate Polysulphane diphosphonates and polysulphane phosphonsulphonates are formed in the reaction of SPO and polysulphane disulphonates in acid solution. The polysulphane phosphonsulphonates are described here for the first time. The same products yielded when S2O reacts with S2P2O. The formation of these compounds depends on nucleophilic attack of the SPO on the sulfur chains of the starting materials, during which growth of the sulfur chains partly occurs.  相似文献   

18.
Specific electrical conductivities and activation energies of the molten binary systems RJ3–MeJ (R = La, Nd, Gd, Dy; Me = Na; K, Cs) have been investigated. In the mixtures with Me = K, Cs there are clear indications to species like RJ, RJ or R2J.  相似文献   

19.
Some tetracoordinated complexes having the formulae, [AgL4]X (L = Triphenyl-arsine; X = NO, ClO and BrO) and [AgL3X] (L = Triphenyl-arsine/phosphine; X = SCN? and NCO?) have been prepared and characterised by analyses, conductance, magnetic susceptibility and infra-red spectroscopy.  相似文献   

20.
Synthesis, Crystal Structures, and Vibrational Spectra of [(Ph3P)2N]2[(W6Cl )I ] · 2 Et2O · 2 CH2Cl2 and [(Ph3P)2N]2[(W6Cl )(NCS) ] · 2 CH2Cl2 By treatment of [(W6Cl)I]2– with (SCN)2 in dichloromethane at –20 °C the hexaisothiocyanato cluster anion [(W6Cl)(NCS)]2– is formed. X‐ray structure determinations have been performed on single crystals of [(Ph3P)2N]2[(W6Cl)I] · 2 CH2Cl2 · 2 Et2O ( 1 ) (triclinic, space group P1, a = 10.324(5), b = 14.908(3), c = 17.734(8) Å, α = 112.78(2)°, β = 99.13(3)°, γ = 92.02(3)°, Z = 1) and [(Ph3P)2N]2[(W6Cl)(NCS)] · 2 CH2Cl2 ( 2 ) (triclinic, space group P1, a = 11.115(2), b = 14.839(2), c = 17.036(3) Å, α = 104.46(1)°, β = 105.75(2)°, γ = 110.59(1)°, Z = 1). The thiocyanate ligands of 2 are bound exclusively via N atoms with W–N bond lengths of 2.091–2.107 Å, W–N–C angles of 173.1–176.9° and N–C–S angles of 178.1–179.3°. The vibrational spectra exhibit characteristic innerligand vibrations at 2067–2045 (νCN), 879–867 (νCS) and 490–482 (δNCS). Based on the molekular parameters of the X‐ray determination of 1 the vibrational spectra of the corresponding (n‐Bu4N) salt of 1 are assigned by normal coordinate analysis. The valence force constants are fd(WW) = 1.61, fd(WI) = 1.23 and fd(WCl) = 1.10 mdyn/Å.  相似文献   

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