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1.
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   

2.
Vibration spectra and force constants of the series O2PF — S2PF — S2P(CH3). The vibrational spectra of OSPF, S2PF, S2PF(CH3) and S2P(CN) are reported and discussed with O2PF and S2P(CH3). On the basis of a simplified valence-force-field the force constants are calculated and the bonding relations are discussed. In the ions, f PF is lower than in corresponding molecules. The ionic charge is distributed over nearly all atoms of the ions.  相似文献   

3.
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   

4.
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   

5.
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   

6.
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   

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.
The coordination polymers [(CuCN)2(μ-2 Mepyz)], [CuCN(μ-2 Mepyz)] and [CuCN(μ-4 Mepym)] ( 1 – 3 ) (2 Mepyz = 2-methylpyrazine; 4 Mepym = 4-methylpyrimidine) may be prepared by self-assembly in acetonitrile solution at 100 °C ( 1 , 3 ) or without solvent at 20 °C ( 2 ). All three contain [CuCN] chains that are bridged by the bidentate aromatic ligands into sheets in 1 and 3 D frameworks in 2 and 3 . Reaction of CuSCN with these heterocyclic diazines at 100 °C leads to formation of the lamellar coordination polymers [(CuSCN)(μ-2 Mepyz)] ( 4 ) and [CuSCN · (4 Mepym-κN1)] ( 5 ), which contain respectively [CuSCN] chains and trans-trans fused [CuSCN] sheets as substructures. The presence of an asymmetric substitution pattern in 2 Mepyz and 4 Mepym induces the adoption of a chiral structure by 2 and 5 (space groups P212121 and P1).  相似文献   

9.
On the Formation of Monoselenane and Monotellurane Disulphane-diphosphonate by the Reaction of SPO with Seleno and Telluropolythionates In the reaction of seleno- and telluropolythionates with SPO, SeS2P2O and TeS2P2O are formed and are described for the first time. Polysulfphane-diphosphonates, -disulphonates and -phosphonsulphonates occur as side and consecutive products. By evaluation of radiochemical double labelling with the nuclide pairs 35S? 32P and 35S? 75Se, it is possible to identify the products formed and obtain information about the reaction mechanism.  相似文献   

10.
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   

11.
Bimetallic and trimetallic compounds containing unsupported bonds of subgroup 4 metals (M = Ti, Zr, Hf) and Co were prepared by hydride elimination (A) from RM derivatives (R1 = PhCH2; RN; R2 = Me, Et)) and by salt elimination (B) from RMX (X = Cl, Br; R.1 = PhCH2, RN and R3O; R3= i-Pr, n-Bu)) by reaction with HCo(CO)4 and Na[Co(CO)4], respectively. Compounds RMCo(CO)4 with R1 = PhCH2, RM[Co(CO)4]2 R.1 = PhCH2, were prepared both by methods A and B, while (R3O)4-n Ti[Co(Co)4]n (n = 1, 2) compounds were obtained by reaction B. Several tertiary phosphine and phosphite derivatives of the former two types were obtained by substitution of a carbonyl group by PR ligand or by A type reaction of HCo(CO)3(PR with RM compounds.  相似文献   

12.
The crystal structure of the title compound has been determined from three dimensional x-ray data obtained by the multiple film method. The space group is P2l/n and the cell dimensions are: a = 14.90, b = 16.84, c = 8.38 Å; β = 93.5° Z = 4. The structure is formed by discrete Co (en) and Fe(CN) ions, both of which have an octahedral configuration. The Fe(CN) ions are approximately octahedrally surrounded by the Co (en) ions while arrangement of Fe (CN) ions around the Co(en) ions completely differs from an octahedron. The mean Fe? C and Co? C dustances are 1.91 and 2.01 Å, respectively. The water molecules do not play an important role in the structure and all distances between oxygen and other atoms indicate the presence of very weak hydrogen bonds. The salts M (en)3 Q(CN)6 · H2O, where M = Co and Cr and Q = Cr, Mn, Fe and Co, are all isomorphous.  相似文献   

13.
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   

14.
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   

15.
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   

16.
High and Low Spin Behaviour of Ni3+?Ions in Octahedral Coordination The compounds Cs2NaNiF6, Cs2KNiF6, Rb2KNiF6, K3NiF6, and Na3NiF6 were investigated by ligand field and EPR spectroscopy between 298 and 4,2 K. These fluorides ? with the exception of the first one – crystallise in the cubic elpasolite lattice or in distorted modifications of this structure type and contain the Ni3+ ions in the low spin configuration te. This configuration is stabilised versus the high spin alternative te by an appreciable Jahn-Teller splitting of the 2Eg-state of about 7000 cm?1. The NiF6-octahedra are tetragonally elongated, the distortion being dynamical at 298 K. In case of the cubic compound Rb2KNiF6 a transition to a tetragonal structure with c/a > 1 as a consequence of a ferrodistortive Jahn-Teller ordering is observed at lower temperatures. It is calculated from the anisotropic g-parameters, that the first excited quartet level 4A2g(4T1g ? te) has an energy which is about 1000 cm?1 higher than that of the 2A1g(2Eg ? te) groundstate. Spin-orbit interactions between the energetically neighboured 2A1g(2Eg) and 4A2g, 4Eg(4T1g) states lead to third order contributions to the g-factors, which are very sensitive with respect to the doublet-quartet separation. In the hexagonal compound Cs2NaNiF6 finally, in which half of the Ni3+ ions occupy octahedral sites connected by common corners as in the other fluorides, while the other half is located in octahedral sites with common faces, high and low spin Ni3+ ions are found side by side. Obviously the latter half of these Ni3+ ions is geometrically restricted with respect to a Jahn-Teller distortion and hence the high spin configuration energetically favoured.  相似文献   

17.
On Hexagonal Perovskites with Cationic Vacancies. XXIV. Rhombohedral 9 L Stacking Polytypes in the Systems Ba3W M □O9?x/2x?2 with MV = Nb, Ta In the system Ba3WNb□O9?x/2x/2 stacking polytypes of rhombohedral 9 L type (sequence (hhc)3; space group R3 m) can be prepared with ~1/3 ? × ? 2. For x = 2(Ba3Nb2□O8□) two modifications are formed. In the corresponding Ta system the phase with is reduced to a smaller region with x ? 1/3.  相似文献   

18.
Treatment of chlorination products of rare earths oxidesulphates with methanol yields chloride-sulphates MIIIClSO4 as residues. Thermal decomposition of chloride-sulphates yields oxide-sulphates MO2SO4; as intermediates, mixtures of the composition MO2SO4? M(SO4)3 are obtained.  相似文献   

19.
The reaction of MO (M = V, Re) with H2S investigated by spectrophotometry, indicated the existence of two new thioanions VO2S and ReOS. Their spectra are compared with known relationships in those of the thioanions of molybdenum and tungsten. A proposal for the electronic spectrum of VO3S3? is given.  相似文献   

20.
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   

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