Die Kristallstruktur von Perowskiten ANiIIMVIO6. II. Das Sr2NiWO6

The Crystal Structure of Perovskites A Ni^IIM^VIO₆. II. Sr₂NiWO₆ The results of an X-ray single crystal study of the perovskite Sr[Ni^IIW^VI]⁽⁶⁾O₆, ordered in the octahedral sites, are given. While Sr[Ni^IITe^VI]⁽⁶⁾O₆ crystallizes in a monoclinically deformed structure of the perovskite (elpasolite) type, showing a phase transition to a tetragonal lattice at 675 °K, Sr[Ni^IIW^VI]⁽⁶⁾O₆ is tetragonal already at 298°K (space group: C; a = b = 5.559 Å; c = 7.918 Å; Z = 2). The Ni? O distances found for the tungsten compound are nearly identical with those of the tellurium perovskite. In contradiction to crystal field theory very different values of the ligand field parameter Δ (ca. 25%) are observed for these two compounds however. Obviously this effect is caused by the rather different kind of bonding within the NiO₆ polyhedra in the two compounds. On the basis of the structural results the Ni? O-bonding in the two perovskites is discussed in dependence of the next nearest cationic environment.     

Darstellung,Kristallstrukturen und Schwingungsspektren von [OsBr(acac)(PPh3)] und [OsBr(acac)(AsPh3)]

Synthesis, Crystal Structures, and Vibrational Spectra of [OsBr(acac)(PPh₃)] and [OsBr(acac)(AsPh₃)] By reaction of tetrabromoacetylacetonatoosmate(IV) with PPh₃ or AsPh₃ in ethanol the complexes [OsBr(acac)(PPh₃)] ( 1 ) and [OsBr(acac)(AsPh₃)] ( 2 ) are formed, which are purified by chromatography on silica gel. X-ray structure determinations of single crystals of ( 1 ) (monoclinic, space group P 2₁/n, a = 13.035(2), b = 18.2640(14), c = 16.636(3) Å, β = 112.776(14)°, Z = 4) and ( 2 ) (monoclinic, space group P 2₁/c, a = 13.23(5), b = 18.35(2), c = 16.65(2) Å, β = 112.9(5)°, Z = 4) result in mean bond distances Os–P = 2.413, Os–As = 2.483, Os–Br = 2.488 and Os–O = 2.037 Å. The vibrational spectra (10 K) exhibit the inner ligand vibrations of the acac, PPh₃ and AsPh₃ groups with nearly constant frequencies and the stretching vibrations of OsP at 499–522, of OsAs at 330–339, of OsBr at 213–214 and of OsO in the range 460–694 cm^–1.     

Über hexagonale Perowskite mit Kationenfehlstellen. XIV Die rhomboedrischen 12 L-Stapelvarianten Ba2La2BII(W□O12)

On Hexagonal Perovskites with Cationic Vacancies. XIV. The Rhombohedral 12 L-Stacking Polytypes Ba₂La₂B^II(W □O₁₂) Rhombohedral 12 L-stacking polytypes with cationic vacancies of type Ba₂La₂B^II-(W□O₁₂) are reported for B^II = Mg, Zn (white), Ni(light brown) and Co(brown). They crystallize in the space group R3 m, sequences (3 )(1) ? (hhcc)₃. For B^II = Cu, as a consequence of the Jahn Teller effect, a triclinic distorted lattice is observed.     

Darstellung,Kristallstrukturen und Schwingungsspektren von [OsCl(acac)(EPh3)], E = P,As, Sb

Synthesis, Crystal Structures, and Vibrational Spectra of [OsCl(acac)(EPh₃)], E = P, As, Sb By reaction of tetrachloroacetylacetonatoosmate(IV) with PPh₃, AsPh₃ or SbPh₃ in ethanol the complexes [OsCl(acac)(EPh₃)], E = P, As, Sb are formed, which are purified by chromatography on silica gel. X-ray crystal structure determinations of the isotypic single crystals of [OsCl(acac)(EPh₃)] (monoclinic, space group P 2₁/c, Z = 4; E = P ( 1 ): a = 12.972(2), b = 18.255(2), c = 16.517(2) Å, β = 112.61(2)°; E = As ( 2 ): a = 13.173(5), b = 18.299(5), c = 16.429(5) Å, β = 112.346(5)°; E = Sb ( 3 ): a = 13.573(3), b = 18.520(3), c = 16.440(9) Å, β = 111.78(2)°) result in mean bond distances Os–P = 2.412, Os–As = 2.485, Os–Sb = 2.619, Os–Cl = 2.354 and Os–O = 2.032 Å. The IR spectra (10 K) exhibit the inner ligand vibrations of the acac and EPh₃ groups with nearly constant frequencies and the stretching vibrations of OsP at 500–524, of OsAs at 330–339, of OsSb at 271–278, of OsCl at 317–322 and of Os–O in the range 460–694 cm^–1.     

Bildung von Chelat-Liganden aus Pseudohalogenid und Pyrazol in der Koordinationssphäre von PdII und PtII

Formation of Chelate Ligands from Pseudohalide and Pyrazole in the Coordination Sphere of Pd^II and Pt^II New Pd^II and Pt^II complexes of the composition M(L · X)₂ were prepared (X = NCO^?), N(CN), C(CN), L = pyrazole (Pz), 3, 5-dimethylpyrazole (Dmpz) and studied applying IR spectroscopy. The complexes are obtained by nucleophilic addition of imine nitrogen from the pyrazole ring to the carbon from the pseudohalide anion. When the neutral ligand was Dmpz the reaction ran partially anly. With NCS^? and pz only the complex Cu(NCS)₂(Pz)₂ is yield.     

Ag2+ in trigonal-bipyramidaler Umgebung: Neue Fluoride mit zweiwertigem Silber: AgMMF20 (MII = Cd,Ca, Hg; MIV = Zr,Hf)

Ag²⁺ in Trigonal-Bipyramidal Surrounding New Fluorides with Divalent Silver AgM M F₂₀ (M^II = Cd, Ca, Hg; M^IV = Zr, Hf) The intensively green compounds AgMMMF₂₀ (M^II = Cd, Ca, Hg; M^IV = Zr, Hf) have been obtained for the first time as single crystals and investigated by X-ray methods. They crystallize in space group P6₃/m-C_6h² (Nr. 176) with

• a = 1052.0(2) pm, c = 828.6(2) pm (AgCd₃Zr₃F₂₀),
• a = 1048.0(2) pm, c = 832.6(3) pm (AgCd₃Hf₃F₂₀),
• a = 1059.4(2) pm, c = 841.0(3) pm (AgCa₃Zr₃F₂₀),
• a = 1053.7(2) pm, c = 830.6(3) pm (AgCa₃Hf₃F₂₀),
• a = 1058.9(3) pm, c = 832.6(4) pm (AgHg₃Zr₃F₂₀),
• a = 1056.9(2) pm, c = 833.0(3) pm (AgHg₃Hf₃F₂₀), Z = 2.

     

Die binuklearen Produkte der Umsetzung von Grignardreagenzien mit Acetylacetonaten der späten 3d-Elemente und ihre katalytische Wirkung bei der Kreuzkopplung

Binuclear Reaction Products of Grignard Compounds and Transition Metal Acetylacetonates - Catalysts of Cross Coupling In THF Grignard compounds react with transition metal acetylacetonates forming the binuclear complexes (THF)₂Mg(acac)₂M^IIX₂ (M^II ? Fe, Co, Ni; X ? Cl, Br). A characteristic component of these compounds is the octahedral moiety (THF)₂Mg(acac)₂. The coordination of two cis-positioned oxygen donors of this moiety to an M^IIX₂-group builds up a second (tetrahedral) coordination centre. The structure of the binuclear complexes and their vis-spectra are discussed in detail. The new compounds are cross coupling catalysts of acylhalides and Grignard reagents. Probably in the course of the catalytic process the acylhalides are activated at the unsaturated transition metal centre (increase of the coordination number), but the Grignard reagent at the magnesium centre (substitution of one of the weakly bound THF-ligands). This model also explains the different catalytic activity of (THF)₂Mg(acac)₂FeCl₂ and (THF)₂Mg(acac)₂NiBr₂.     

Amorphous Polyethylene by Tandem Action of Cobalt and Titanium Single‐Site Catalysts

Summary: A variety of branched polyethylenes, spanning from semicrystalline LLDPE to completely amorphous, rubbery PE, was obtained from ethylene by homogeneous tandem catalysis using combinations of CoCl₂(N) ( 1 ) (N = [1‐(6‐benzo[b]thiophen‐2‐yl‐pyridin‐2‐yl)‐ethylidlene)‐(2,6‐diisopropyl‐phenyl)‐amine) and [(η⁵‐C₅Me₄)SiMe₂(tBuN)]TiCl₂ ( 2 ) in the presence of MAO at 30 °C. The productivity reached a maximum of 4 570 kg PE (mol Ti · h)⁻¹ at χ_Co = 0.50, yielding a rubbery material with d₂₅ = 0.868 g · cm⁻³ and T_g = −55 °C.

Conversion of ethylene into branched polyethylene using Co^II iminopyridyl complex CoCl₂(N) ( 1 ) and TiCl₂[(η⁵‐C₅Me₄)SiMe₂(tBuN)] ( 2 ).     

Synthese und Struktur von MII[AuF4]2 (MII  Cd,Hg)

Synthesis and Structure of M^II[AuF₄]₂ (M^II ? Cd, Hg) Cd[AuF₄]₂ and the isotypic compound Hg[AuF₄]₂, both are yellow, crystallize tetragonal in the space-group P4/mcc-D (No. 124) with a = 575.0/575.6 pm, c = 1034.8/1042.3 pm and Z = 2. The single-crystals were obtained by solid-state reactions in goldtubes.     

Rb2Co3(H2O)2[B4P6O24(OH)2]: Ein Borophosphat mit ‐Tetraeder‐Anionenteilstruktur und Oktaeder‐Trimeren (CoO12(H2O)2)

Rb₂Co₃(H₂O)₂[B₄P₆O₂₄(OH)₂]: A Borophosphate with ‐Tetrahedral Anionic Partial Structure and Trimers of Octahedra (Co O₁₂(H₂O)₂) Rb₂Co₃(H₂O)₂[B₄P₆O₂₄(OH)₂] is formed under mild hydrothermal conditions (T = 165 °C) from mixtures of RbOH_(aq), CoCl₂, H₃BO₃, and H₃PO₄ (molar ratio 1 : 1 : 1 : 2). The crystal structure (orthorhombic system) was solved by X‐ray single crystal methods (space group Pbca, No. 61; R‐values (all data): R1 = 0.0699, wR2 = 0.0878): a = 950.1(1) pm, b = 1227.2(2) pm, c = 2007.4(2) pm; Z = 4. The anionic partial structure consists of tetrahedral [B₄P₆O₂₄(OH)₂^8–] layers, which contain three‐ and nine‐membered rings. Co^II is octahedrally coordinated by oxygen and oxygen and H₂O ligands, respectively (coordination octahedra CoO₆ and CoO₄(H₂O)₂). Three adjacent coordination octahedra are condensed via common edges to form trimeric units (CoO₁₂(H₂O)₂). The oxidation state +2 of cobalt was confirmed by magnetic measurements. The octahedral trimers are quasi‐isolated. No long‐range magnetic ordering occurs down to 2 K. Rb⁺ is disordered over three crystallographically independent sites within channels of the structure running parallel [010]; the coordination sphere of Rb⁺ is formed by nine oxygen species of the tetrahedral layers, one OH group and one H₂O molecule.     

Die Kristallstruktur von Perowskiten ANiIIMVIO6. I. Das Sr2[NiTe]O6

The structure of the perovskite compound Sr Ni^IITe^{VI (6)}O₆ (1:1 order in the octahedral sites) is described in detail. The obtained Ni? O distance (2.04 Å a_Te–O = 1.91 Å) together with that one within the corresponding tungsten perovskite (part II) will be analyzed quantitatively with respect to the connection between structure and ligand-field as well as EPR data. The comparison of this distance and the spectroscopic results of the tellurium perovskite with corresponding data of Ni^II-doped MgO however shows already now that an interpretation on the basis of an ionic model is impossible     

Über geordnete Perowskite mit Kationenfehlstellen. X. Verbindungen vom Typ ABB□1/4MVIO6 ≙ ABIIB□MO24 mit AII,BII = Ba,Sr, Ca und MVI = U,W

On Ordered Perovskites with Cationic Vacancies. X. Compounds of Type A B B □_1/4M^VIO₆ ? A B^IIB □M O₂₄ with A^II, B^II = Ba, Sr, Ca and M^VI = U, W Perovskites of type Ba₈B^IIB₂^III□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 Ba₈B^IIB□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 AB^IIB□W₄O₂₄. The higher ordered cells with U^VI and W^VI are face centered, which has its origin in an ordering of cationic vacancies.     

Metallorganische Verbindungen der Lanthanoide. 111. Synthese und Charakterisierung kationischer Metallocen-Komplexe der Lanthanoide. Röntgenstrukturanalyse von [CpYb(THF)2][BPh4]

Organometallic Compounds of the Lanthanoids. 111. Synthesis and Characterization of Cationic Metallocene Complexes of the Lanthanoides. X-Ray Crystal Structure of [Cp Yb(THF)₂][BPh₄] Cationic organolanthanoide compounds [(C₅H₄R)₂Sm(THF)₂][BPh₄] (R = ^tBu ( 1 ), SiMe₃ ( 2 )), [PyrSm(THF)][BPh₄] ( 3 ) (Pyr* = NC₄H₂^tBu₂-2,5), [CpLn(THF)₂][BPh₄] (Cp* = C₅Me₅; Ln = Y ( 4 ), Yb ( 5 )), and [(C₅Me₄Et)₂ Ln(THF)₂][BPh₄] (Ln = Y ( 6 ), Sm ( 7 )) have been synthesized by oxidation of the divalent metallocenes [(C₅H₄R)₂Sm(THF)₂] (R = ^tBu, SiMe₃), [PyrSm(THF)], [CpYb(THF), and [(C₅Me₄Et)₂Sm(THF)] with Ag[BPh₄] and by protolysis of the lanthanoide alkyls [CpYMe(THF)], [CpYbCH(SiMe₃)₂], and [(C₅Me₄Et)₂LnCH(SiMe₃)₂] (Ln = Y, Sm) by [NEt₃H][BPh₄]. The ¹H- and ¹³C-NMR spectra of the new compounds are discussed. 5 crystallizes in the space group P2₁/c with a = 10.604(7), b = 21.749(3), c = 19.124(4) Å, β = 96.47(4)°, Z = 4 and V = 4383(3) ų (R = 0.0291 for 8517 observed reflections with F_o ≥ 4σ (F_o).     

Kinetics and mechanism of acetylacetonate transfer from acetylacetonatomanganese(III) to iron(III) in acetonitrile catalysis and inhibition effects

The reaction between tris(acetylacetonato)magnanese(III) and hexa(N,N-dimethylformamide)iron(III) perchlorate in acetonitrile proceeds in two stages. The first stage corresponds to the reaction of pentacoordinated Fe(DMF) with Mn(acac)₃, and the rate-determining step of the second stage consists mainly in the elimination of a DMF ligand from Fe(DMF) to yield Fe(DMF) which reacts rapidly with the manganese complex. The formation of Fe(DMF) is catalyzed by Mn(acac)₃, this catalytic effect being decreased by manganese products. The rate-determining step for the formation of Fe(acac)₃ is the transfer of the first acetylacetonate to yield Fe(acac)²⁺. The final products of iron depend on the ratio of reactant concentrations. With Mn or Fe in excess, Fe(acac)₃ or Fe(acac)²⁺ are mainly produced.     

Über hexagonale Perowskite mit Kationenfehlstellen. XXVI. Ba12Ba2 2/3M 1/3□2O33□3 (MV = Nb,Ta) – die ersten Stapelvarianten eines rhomboedrischen 36 L-Typs

On Hexagonal Perovskites with Cationic Vacancies. XXVI. Ba₁₂Ba_{2 2/3}M _1/3□₂O₃₃□₃ (M^V = Nb, Ta) – the First Stacking Polytypes of a Rhombohedral 36 L-Type In the systems BaO? MO₅(M^V = Nb, Ta) for a Ba:M^V ratio of 2:1 polymorphism is observed. Here the low temperature modifications are described. They crystallize in a rhombohedral 36 L structure with three formula units Ba₁₂Ba_{2 2/3}M _1/3□₂O₃₃□₃ for the trigonal setting (M^V = Nb: a = 5.92₂ Å; c = 93.₂₅ Å; Ta: a = 5,92₂ Å; s = 93.4 Å).     

Selektive Darstellung zweifach diorganophosphido-verbrückter Metallatetrahedrane [Re2(MPR3)2(μ-PR2)2(CO)6] mit Re2M2-Metallgerüst (M = Au,Ag)

Selective Preparation of Twofold Diorganophosphido-bridged Metallatetrahedranes [Re₂(MPR₃)₂(μ-PR₂)₂(CO)₆] with Re₂M₂ Metal Core (M = Au, Ag) The reaction of the in situ prepared salt Li[Re₂(AuPR)(μ-PR₂)(CO)₇Cl] (R = R′ = Cy ( 1 a ), R = Cy, R′ = Ph ( 1 b ), R = Ph, R′ = Cy ( 1 c ), R = Ph, R′ = Et ( 1 d ), R = Ph, R′ = Ph ( 1 e )) with one equivalent HPR in methanolic solution at room temperature yields the neutral cluster complexes [Re₂(AuPR)(μ-PR₂)(CO)₇(ax-HPR) (R = R′ = R″ = Cy ( 2 a ), Ph ( 2 b ), R = R′ = Cy, R″ = Et ( 2 c ), R = Cy, R′ = R″ = Ph ( 2 d ), R = Cy, R′ = Ph, R″ = Et ( 2 e ), R = R″ = Ph, R′ = Et ( 2 f ), R = Ph, R′ = Cy, R″ = Et (2 g)). Photochemically induced these complexes react in the presence of the organic base DBU in THF solution to give the doubly phosphido bridged anions Li[Re₂(AuPR)(μ-PR₂)(μ-PR)(CO)₆], which were characterized as salts PPh₄[Re₂(AuPR)(μ-PR₂)(μ-PR)(CO)₆] (R = R′ = R″ = Ph ( 3 a ), R = R′ = Ph, R″ = Cy ( 3 b ), R = Ph, R′ = Cy, R″ = Et ( 3 c ), R = R″ = Ph, R′ = Et ( 3 d )). These precursor complexes 3 then react with one equivalent of ClMPR (M = Au, Ag) to doubly phosphido bridged metallatetrahedranes [Re₂(MPR₃)₂(μ-PR₂)(μ-PR)(CO)₆] (M = Au, R = R′ = R″ = Ph ( 4 a ), M = Au, R′ = Et, R = R″ = Ph ( 4 b ), M = Au, R = R′ = Ph, R″ = Cy ( 4 c ), M = Au, R = Cy, R′ = Ph, R″ = Et ( 4 d ), M = Ag, R = R′ = R″ = Ph ( 4 e )). All isolated cluster complexes were characterized and identified by the following analytical methods: NMR- (¹H, ³¹P) and ν(CO) IR-spectroscopy and, additionally, complexes 2 b , 4 a and 4 e by X-ray structure analysis.     

Synthesis of a Triamidoamine Nd2Cl2(μ5-O)Li3 Cluster

[Li(THF)₄][[NN]₂Nd₂Cl₂(μ₅-O)Li₃] ( 2 ) ([NN]^3– = ([Me₃SiNCH₂CH₂)₃N]^3–) was prepared by transmetallation of Li₃[NN] with anhydrous neodymium trichloride in THF. After recrystallization from diethylether/pentane (1 : 2) light blue crystals of 2 were obtained, which were characterized by single crystal X-ray diffraction. Space group: P2₁/n, Z = 4, lattice dimensions at 203 K: a = 1260.8(3), b = 3832.5(8), c = 1569.2(3) pm, β = 106.07(3)°, R₁ = 0.0541. In the anion of 2 a nearly trigonal bipyramidal [Nd₂Li₃(μ₅-O)]⁷⁺ unit is observed.     

Nitridsulfidchloride der Lanthanide: II. Der Formeltyp M6N3S4Cl (M = La?Nd)

Nitride Sulfide Chlorides of the Lanthanides. II. The Composition M₆N₃S₄Cl (M = La? Nd) The oxidation of the “light” lanthanides (M = La? Nd) with sulfur and NaN₃ in the presence of the chlorides MCl₃ yields chlorine-poor nitride sulfide chlorides with the composition M₆N₃S₄Cl when appropriate molar ratios of the reactants are used. Additional NaCl as a flux secures complete and fast reactions (7 d) at 850°C in evacuated silica vessels as well as single-crystalline products (red-brown needles). The crystal structure was determined from X-ray single crystal data for the limiting representatives La₆N₃S₄Cl (orthorhombic, Pnma (no. 62), Z = 4, a = 1159.7(4), b = 410.95(7), c = 2756.8(9)pm, R = 0.030, R_w = 0.027) and Nd₆N₃S₄Cl (a = 1137.1(3), b = 399.34(6), c = 2687.6(9)pm, R = 0.034, R_w = 0.033). Guinier powder data revealed the cerium and praseodymium analogues to be isotypic. The crystal structure exhibits two different chains of connected [NM₄] tetrahedra which are commensurate in translation. Six crystallographically different M³⁺ are present, two of them (M1 and M2) build up the chain [(N1)(M1) · (M2)]³⁺ together with (N1)^3? by cis-edge connection of tetrahedra. The four remainders (M3? M6) arrange as pairs [N₂M₆] of edge-shared [NM₄] tetrahedra with (N2)^3? and (N3)^3? which are further connected via four vertices to form the [(M5)(N-2){(M3)_(1+1)/(1+1)(M4)_(1+1)/(1+1))}^e(N3)(M6)]⁶⁺ double chain. Bundled along [010] like a closest packing of rods, both types of chains are held together by five crystallographically different but by X-ray diffraction indistinguishable anions S^2? (S1? S4) and Cl^? adjusting the charge balance in a molar ratio of 4:1.     

Herstellung von Fluorophosphaten,Difluorophosphaten, Fluorophsophonaten und Fluorophosphiten in fluoridhaltigen Harnstoffschmelzen

Preparation of Fluorophosphates, Difluorophosphates, Fluorophosphonates, and Fluorophosphites in Fluoride-containing Urea Melts Phosphoric acid, phosphonic acid, and organylphosphonic acid react on heating in fluoride-containing urea melts in high yields to fluorophosphates, MPHO₂F, organylfluorophosphonates, M¹RPO₂F, organylpolyfluorophosphonates, MR¹CX(PO₂F)₂, MN(CH₂PO₂F)₃, and phosphonoorganylfluorophosphonates, MR¹CX(PO₃)PO₂F (M¹ = K, NH₄; R = organic substituent; R¹ = H, organic substituent; X = OH, NH₂, NR₂). The reaction mechanism of the formation of fluorophosphate ions in fluoride containing urea melts is discussed.     

Einelektronen-Redox-Reaktionen von Octaphenyl[4]radialen: Erzeugung und ESR/ENDOR-Charakterisierung seines Radikal-Anions und Radikal-Kations

One-Electron Redox Reactions of Octaphenyl[4]radialene: Generation and ESR/ENDOR Characterisation of Its Radical Anion and Radical Cation The cyclovoltammograms of octaphenyl[4]radialene in DMF or THF at room temperature disclose each two quasireversible reduction and oxidation potentials at ?1.4 V/?1.7 V and +0.7 V/+0.9 V. Accordingly, both the radical anion and the radical cation can be generated: Ph₈C by K metal mirror reduction of a [2.2.2]cryptand containing THF solution, and Ph₈C by TI^3⊕(^?OOCCF₃)₃ oxidation in H₂CCl₂. Their ESR/ENDOR and General Triple spectra differ considerably in the number of resolved ¹H couplings (M^·?: 5 and M^·⊕: 3) as well as in their spectral widths (M^·?: a_1H 0.090 to 0.017 mT; M^·⊕: a_1H 0.066 to 0.023 mT) suggesting different changes in the D_2d structure of the neutral molecule on electron uptake or extrusion.