The Representation of Electrical Conductances for Polyvalent Electrolytes by the Quint-Viallard Conductivity Equation. Part 3. Unsymmetrical 3:1, 1:3, 3:2, 4:1, 1:4, 4:2, 2:4, 1:5 1:6 and 6:1 Type Electrolytes. Dilute Aqueous Solutions of Rare Earth Salts, Various Cyanides and other Salts

Electrical conductivities of dilute aqueous solutions for unsymmetrical electrolytes of the type 3:1, 1:3, 3:2, 4:1, 1:4, 4:2, 2:4, 1:5 1:6 and 6:1 are reexamined in the framework of the Quint-Viallard conductivity equations, in order to obtain a uniform representation of their conductivities. The molar and equivalent limiting conductances were evaluated with ion association constants, which were treated as adjustable parameters. The derived values were compared with corresponding results from the literature. The following electrolytes are considered: rare earth (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er) halides, perchlorides, nitrates and sulfates; hexamminecobalt and tris-ethylenediaminecobalt halides, perchlorides, nitrates and sulfates; [Ni₂(trien)₃]Cl₄, [Pt(pn)₃]Cl₄, [Co₂(trien)₃]Cl₆; cyanides K₃[Fe(CN)₆], K₃[Co(CN)₆], M₃[W(CN)₈] with M=Na, K, Rb, Cs; Ca₂[Fe(CN)₆], K₄[Fe(CN)₆], K₄[Mo(CN)₈], K₄[W(CN)₈], K₄[Ru(CN)₈], (Me₄N)₄[Fe(CN)₆], (Pr₄N)₄[Fe(CN)₆], K₄[Mo(CN)₈], (Me₄N)₄[Mo(CN)₈], (Et₄N)₄[Mo(CN)₈] and (Pr₄N)₄[Mo(CN)₈]; phosphates Na₄P₂O₇, Na₄P₄O₁₂, Na₅P₃O₁₀, Na₆P₆O₁₈ and (Me₄N)₄P₄O₁₂.     

Übergangsmetall-methylen-komplexe: LIV. Eine ruthenium-ruthenium-doppelbindung: Synthese und methylen-addition

The first organometallic compound containing a reactive multiple bond between the ruthenium atoms has been synthesized by nitrosylation of a carbonylmetal precursor. Treatment of [(η⁵-C₅H₅)Ru(CO)₂]₂ (1) with nitrogen monoxide in n-decane at 170°C gives the black, air-stable nitrosyl derivative [(η₅ -C₅H₅)Ru(μ-NO)]₂ (2) in 75–80% yield. The composition of this molecule as well as the subsequent addition of a bridging methylene group with formation of (μ-CH₂)[η⁵C₅H₅)Ru(NO)]₂ (3a) shows that a metal—metal double bond is present in compound 2; this molecule is thus isostructural with the known iron analogue [(η⁵-C₅H₅)Fe(μ-NO)]₂.     

Dijodamin: Acylderivate

By reaction of N,N-dibromocarboxamides with iodine the following N,N-diiodocarboxamides were prepared for the first time: HCONI₂, CH₃CONI₂, CH₃CH₂CONI₂, ClCH₂CONI₂, and C₆H₅CONI₂. The intensely coloured compounds are unexpectedly thermally stable in the solide state. They are, however, very unstable in solution. N,N-Diiodobenzamide is shown to decompose by thermal dissociation to iodine and benzoyl nitrene.On the grounds of their low solubility, high thermal stability and spectroscopic studies, a polymeric structure is proposed for the cristalline compounds. The new compound type is compared with the known N,N-dibromo- and N-monoiodo-carboxamides, and with N,N-diiodoamines.     

Pentafluorethylschwefeltrifluorid: Synthese und Reaktionen

Pentafluorethyl Sulfurtrifluoride: Synthesis and Reactions By oxidation of (C₂F₅S?)₂ ( 1 ) with AgF₂ at 0°C a mixture of C₂F₅SF₃ ( 2 ) and C₂F₅SF₅ ( 3 ) besides C₂F₅S(O)F ( 4 ) is formed. With elemental fluorine only 3 is isolated, an intermediate in this reaction is (C₂F₅SF₄?)₂ ( 5 ). At ?40 to ?30°C the mixture of 2, 3 and 4 was reacted with TASF and AsF₅, to give TAS⁺ C₂F₅SF₄^? ( 6 ), TAS⁺ C₂F₅S(O)F₂^? ( 7 ) and C₂F₅SF₂⁺AsF₆^? ( 8 ), respectively. While 6 and 7 decompose rapidly in solution even at low temperatures, of thermally stable 8 the solid state structure was determined by x-ray diffraction.     

Phosphaacetylenehexacarbonyldicobalt complexes: new cluster lewis bases

The reaction of RCCl₂ PCl₂ (R = CH₃, C₆ H₅, (CH₃)₃ Si) with dicobalt octacarbonyl in THF at ?78°C gave the new (RCP)Co₂(CO)₅ complexes, which contain the CPCo₂ cluster unit, as air-sensitive red oils. The complex with R = CH₃ reacted with (OC)₅M-THF to give the corresponding M(CO)₅ (M = Cr, W) adducts and the complex with R = C₆H₅ could be acetylated in the para position with CH₃ C(O)Cl/AlCl₃.     

Chloromethylsilane functionalised dendrimers: synthesis and reactivity

Tetraallylsilane was functionalised using (chloromethyl)dimethylsilane to give the first generation chloromethyl terminated dendrimer 1. The resulting dendrimer was successfully reacted with K[CpM(CO)₂] (Cp=η⁵-C₅H₅; M=Fe, Ru) to give Si[(CH₂)₃SiMe₂CH₂MCp(CO)₂]₄ functionalised dendrimers in satisfactory yield. Reaction of dendrimer 1 with NaI in acetone gave the -SiMe₂CH₂I functionalised dendrimer, while reactions of 1 with K[CpM(CO)₃] (M=Mo, W, Re), Li[C₅Me₄H], Na[C₅Me₄H], the cobaloxime nucleophile or tert-BuLi were not successful.     

π-Olefin-iridium-komplexe : IV. Umsetzungen von chloro-dien-iridium-verbindungen mit lithiumorganylen

The complexes [(1,3-C₆H₈)₂IrR] and [(1,3-C₇H₁₀)₂IrR] (R = CH₃, C₆H₅) are obtained by reaction of the corresponding chloro compounds with RLi. Interaction of [Ir(COD)Cl]₂ (COD = 1,5-cyclooctadiene) with CH₃Li in the presence of 1,3-cyclohexadiene or isoprene yields [(COD)(1,3-C₆H₈IrCH₃] and [(COD)(C₅H₈IrCH₃], respectively. The products of the reaction of chlorodicyclodieneiridium with n-C₄H₉Li depend on the ring size of the cyclodiene ligands; with 1,3-cyclohexadiene [(1,3-C₆H₈)₂IrH] is formed while with 1,3-cycloheptadiene [(1,3-C₇H₁₀)(C₇H₉)Ir] is obtained together with [(1,3-C₇H₁₀)₃Ir₂(μ-H)₂]. Chemical and spectroscopic properties of the new compounds are discussed.     

Tetraphenylbismuth aroxides: Synthesis and structure

Tetraphenylbismuth aroxides Ph4BiOAr (Ar = C₆H₃Cl₂-2,6, C₆H₂(Br₂-2,6)(t-Bu)-4, C₆H₂(Br₂-2,6)(NO₂)-4 · 1/2C₆H₆, C₆H₃(NO₂)₂-2,4, C₆H₂(NO₂)₃-2,4,6) were synthesized in the yield up to 90% by the reaction of pentaphenylbismuth with phenols and triphenylbismuth diaroxides and studied by X-ray diffraction. The Bi atoms of tetraphenylbismuth aroxides have a distorted trigonal-bipyramidal coordination with the axial O atom of the aroxide group. The axial angles CBiO vary from 171.7(2)° to 179.3(3)°. The distances Bi-O change in the interval 2.453(2)–2.925(7) Å depending on the nature of substituents in the aromatic ring of the phenol residue. The increasing distance Bi-O in the series of compounds under study correlates with the tendency of the BiC₄ fragment to form the tetrahedral configuration.     

Übergangsmetall—methylen-komplexe: LXI. Übergangsmetall—vinyliden-komplexe: Neuartige synthese aus diazoalken-vorstufen

The diazoolefines of composition N₂CCR₂ (R/R = CH₃/CH₃ and(-CH₂-)₅) are suitable precursors of the corresponding vinylidene ligands CCR₂. Thus, treatment of the RhRh complex [(η⁵-C₅Me₅)Rh(μ-CO)]₂ (1) with the N-nitrosourethanes 2a and 2b, resp., in the presence of lithium t-butoxide yields the otherwise inaccessible μ-vinylidene complexes (μ-CCR₂)[(η⁵-C₅Me₅)Rh(CO)]₂ (R = CH₃ (3a), R,R = (-CH₂-)₅ (3b)). The analogous cobalt compound (μ-CCMe₂)[(η⁵-C₅Me₅)Co(CO)]₂ (5a) is obtained similarly. This procedure extends the well-documented diazoalkane method for the synthesis of μ-alkylidene complexes to the less stable diazoalkenes. A single-crystal X-ray diffraction study of the dimethylvinylidene derivative 3a shows the CMe₂ ligand to adopt an almost symmetrically metal-bridging position (d(RhC) 197.8(1) and 204.3(1) pm), with a rhodium-rhodium single bond completing a three-membered Rh₂C-metallacycle (d(RhRh) 268.4(0) pm) analogous with cyclopropane.     

Ethylene/propylene copolymers with vanadium-based catalysts: Cocatalyst effect

Ethylene/propylene copolymers were obtained with vanadium-based catalysts. Different aluminium alkyls were employed as cocatalyst: Al(C₂H₅)₂Cl/promoter, Al(i-C₄H₉)₃, Al(n-C₆H₁₃)₃. and Al(n-C₈H₁₇)₃. The influence of the cocatalyst on the molecular weight, the molecular weight distribution and the microstructure of the copolymers was investigated through GPC, DSC, ¹³C–NMR analysis and fractionation. AIR₃ afforded a polymerization activity that was much higher with respect to Al(C₂H₅)₂Cl/nBPCC, but with the latter cocatalyst system copolymers were obtained with a more homogeneous distribution of the monomers and the absence of crystallinity. A comparison with ethylene/propylene copolymers obtained with a V(Acac)₃/Al(C₂H₅)₂Cl/promoter and with a high-yield Ti-based catalyst is also presented.     

Dibromamin: Alkylderivate

The N,N-dibrominated amines easily can be prepared by reaction of the corresponding amines with heterocyclic N-bromo imides. Some properties and reactions are given. As just reported they show a thermal instability. Only three compounds could be prepared in pure critalline state: CH₃NBr₂ (until now just known as a solution), Br₂NCH₂CH₂NBr₂ and (CH₃)₃CNBr₂. The last one shows a superior stability and was investigated more exactly. According to: $$(CH_3 )_3 CNBr_2 + (CH_3 )_3 CNH_2 \rightleftarrows 2 (CH_3 )_3 CNHBr$$ for the first time a cristalline N-monobromomonoalkylamine was prepared. Comparison with the acyl derivatives of dibromoamine shows a partly differing behaviour of the alkyl derivatives, which is explained by differences in the polarisation of the N?Br bonding.     

Mehrfachbindungen zwischen hauptgruppenelementen und übergangsmetallen: IV. Chrom-schwefel- und chrom-selen-bindungen: Knüpfung,umwandlungsreaktionen und alkylidenaddition

New dinuclear chromium—sulfur complexes containing one or two sulfur atoms are formed upon reaction of the ionic complex K[(η⁵-C₅Me₅)Cr(CO)₃] (Me = CH₃; 1) with trithiazyl trichloride at temperatures below ambient. The μ(η¹ :η²)-disulfur complex 2a of composition (η⁵-C₅Me₅)₂Cr₂(CO)₅S₂ undergoes concomitant CO-elimination and desulfurization on heating or in the presence of triphenylphosphine; the CrSCr-complex (η⁵-C₅Me₅)₂Cr₂(CO)₄S (2c) is formed in these cases. When diazomethane is treated with 2a, a novel μ,η²-thio- formaldehyde complex (2d) results, again following CO- and S-extrusion. While the triple-bonded CrSCr-skeleton present in 2c does not allow alkylidene additions, such reactions, which proceed cleanly, are observed with the corresponding μ⁵-seleno derivative (η⁵-C₅H₅)₂Cr₂(CO)₄Se (4) synthesized from Na[(η⁵-C₅H₅)Cr(CO)₃] and sodium selenite in the presence of hydrochloric acid.     

Ternäre Thallium-Indium-Sulfide: Eine Zusammenfassung

Ternary Thallium Indium Sulfides: A Summary Combined thermal and X-Ray analyses in the ternary system Thallium—Indium—Sulfur show, that the two binary sections Tl₂S? In₂S₃ and TlS? InS contain ternary compounds with unique crystal structures. The chemical formulas of these ternary solids are TlIn₅S₈, TlIn₃S₅, TlInS₂ and Tl₃InS₃ for the section Tl₂S? In₂S₃ and TlIn₅S₆ as well as Tl₃In₅S₈ (metastable high temperature phase) for the section TlS? InS respectively. With TlIn₅S₇ an additional ternary solid could be detected, which is located outside the two sections. It is derived from the binary mixed valence compound In₆S₇ by complete substitution of In⁺ by Tl⁺. The following ionic formulations make the mixed valence character of the ternary Thallium—Indium-Sulfides reasonable: TlIn₅S₈ = Tl⁺(In³⁺)₅(S^2?)₈, TlIn₃S₅ = Tl⁺ (In³⁺)₃(S^2?)₅, TlInS₂ = Tl⁺In³⁺(S^2?)₂, Tl₃InS₃ = (Tl⁺)₃In³⁺ · (S^2?)₃, TlIn₅S₆ = Tl⁺([In₂]⁴⁺)₂In³⁺ (S^2?)₆, Tl₃In₅S₈ = 4 × [(Tl⁺)_0,75 · (In⁺)_0,25In³⁺(S^2?)₂], TlIn₅S₇ = Tl⁺[In₂]⁴⁺ (In³⁺)₃(S^2?)₇. All compounds contain Tl⁺-ions in a characteristic “lone pair coordination” of S^2? ions. Indium atoms however occur with the oxidation numbers +2 (formal, In₂ dumb bells with covalent In? In bonding) and +3 (with In³⁺ in tetrahedral and octahedral coordination of S^2?). Chemical preparation, crystal chemistry and general properties of the ternary solids are discussed, summarized and compared to each other.     

Aminoderivate hydrierter Oligosilane: Darstellung,Charakterisierung und Eigenschaften

Summary Amino derivatives of linear and branched tri- und tetrasilanes R₂N-H₂Si(SiH₂)SiH₂-NR₂ H₃SiSiHNR₂SiHNR₂SiH₃, R₂N-H₂SiSiH₂SiH₂SiH₂-NR₂ und (R₂N-H₂Si)₂SiHSiH(SiH₂-NR₂)₂ with R = Et, SiMe₃ are formed by the reaction of the corresponding bromooligosilanes with suitable amines or alkali metal amides. Product distribution and yields are strongly influenced by the nucleophilicity of the amino reagent and by the structure of the SiSi-backbone. The structures proposed for the aminopolysilanes thus prepared are proved by²⁹Si-,¹H-NMR-and MS-investigations.

     

Silicium-stickstoff-fluorverbidungen: V. Darstellung neuer silylaminofluorsilane

Compounds of the composition RR′SiFNR″Si(CH₃)₃ (R = H, F, CH₃, C₂H₅, C₃H₇, C₂H₃, C₆H₅, C(CH₃)₃; R = F, CH₃, C₆H₅; R″ = CH₃, C(CH₃)₃, Si(CH₃)₃) are obtained by the reaction of silicontetrafluoride or organo-substituted silicon-fluorides with the lithium salts of alkylsilylamines in a molar ratio of $\text{1}\text{1}$. The disubstituted compounds RSiF(NR′Si(CH₃)₃)₂ (R = H, F, CH₃, C₂H₃, C₆H₅; R′ = CH₃, C(CH₃)₃) result when the reactants are in a $\text{1}\text{2}$ molar-ratio. Likewise the unsymmetrical siliconfluorsilylamines of the formulae F₂Si(NRSi(CH₃)₃) (NR′Si(CH₃)₃) (R = CH₃, R′ = C(CH₃)₃), as well as the trisubstituted compounds FSi(NCH₃Si(CH₃)₃)₃ and FSi(NCH₃Si(CH₃)₃)₂(N(Si(CH₃)₃)₂) were made. By reacting phenyltrifluorsilane with dialkylamines ($\text{1}\text{2}$) C₆H₅SiF₂NR₂(R = CH₃, C₂H₅) was obtained. The IR-, mass-, ¹H and ¹⁹F NMR spectra of the above-mentioned compounds are reported.     

Phosphin-stabilisierte carbonylnitrosylvanadium-verbindungen: Darstellung und spektroskopische eigenschaften

Numerous new complexes of the type V(CO)₅_n(NO)L_n, have been prepared either by nitrosylation of [V(CO)₆_nL_n]^?(n  2, 3) with NOX (X  Cl, BF₄) and [Co(NO)₂Br]₂, resp., or by reaction of L with “V(CO)₅NO” generated in situ. The compounds comprise n  1: L  PPh₃, PMe₂H, P(OMe)₃ and Ph₂PCH_2?PPh₂ (dppm); n  2: L₂2  2 PMe₂H, 2 PMe₃, 2 P(OMe)₃, dppm, Ph₂P(CH₂)_2?PPh₂, Ph₂P(CH₂)₃,PPh₂, Me₂P(CH₂)₂PMe₂, Ph₂As(CH₂)₂AsPh₂, o_?C₆H₄(AsMe₂)₂ (diars) and o_?C₆H₄(AsPh₂)PPh₂; n  3: L₃  1.5 diars and CH₃C(CH₂PPh₂)₃. IR (CO and NO stretching region) and ⁵¹V NMR spectra are discussed; for n  2 and 3, the positions of the arsine and phosphine ligands relative to NO are either cis for all the ligand functions (arsines) or cis/trans.     

Titrations with extractive end-points: The dichromate titration

A method for the titration of iron(II) with K₂Cr₂O₇ in coloured solutions is reported, using the extraction of Cr₂O₇^-2 ions as (Ph₃MeAs)₂Cr₂O₇ at the end-point. The method is applicable to titration with $\text{N}\text{10}$ K₂Cr₂O₇ in the presence of normally interfering coloured cations in molar concentrations up to 50 times that of the iron (II). The method may be used to estimate iron in ferrous alloys, usually without separation from the other metals present. A stable dichromate, (Ph₃MeAs)₂Cr₂O₇ has been isolated.     

BIFEVOX Composites: Manufacture and Characterization

Design of composites is a way to improve the quality of solid electrolytes. By mechanically mixing and annealing substituted bismuth vanadate with nanosized aluminum, bismuth, and zirconium binary oxides, we obtained heterogeneous materials Bi₄V_1.7Fe_0.3O_{11 – δ}/xAl₂O₃, Bi₄V_1.7Fe_0.3O_{11 – δ}/xBi₂O₃, and Bi₄V_1.7Fe_0.3O_{11 – δ}/xYSZ. The investigation tools were X-ray powder diffraction and electron microscopy with energy-dispersive microanalysis. The composition of materials was studied, the non-interaction of components was elucidated in the aluminum oxide and zirconium oxide composite series, and a nonuniform distribution of nanopowder particles across the surfaces and cleaves of sinters was discovered. The bismuth atoms from bismuth oxide were shown to be capable of incorporating into the Bi₄Fe_0.3V_1.7O_{11 – δ} structure. The charge transport characteristics of the materials were studied by impedance spectroscopy. No changes were observed in logσ–10³/T trends in composites with various binary oxides and various oxide contents. An increase in binary oxide concentration was shown to give rise to an insignificant decay in electrical conductivity.     

Nitrosyl Rhenium Complexes: Thiocyanato Derivatives

Fusion of K₂[Re(NO)Cl₅] with KSCN produces the ion [Re(NO)(SCN)₅]^2? which has been isolated as free acid and K⁺, Na⁺, NMe₄⁺, Pb²⁺, Hg²⁺, phen H⁺ and dipyH⁺ salts. A salt of composition Hg₂[Re(NO)(SCN)₇] has also been prepared. The species [Re(NO)Cl(SCN)₄]^2? has been obtained from the reaction of H₂[Re(NO)(SCN)₅] with HCl in aqueous medium and its NMe₄⁺ salt has been isolated. Hydrated Re(NO)Cl₃ reacts with KSCN in aqueous medium to produce the ion [Re(NO)Cl₂(SCN)₃]^2? which has been isolated as its phenH⁺ and dipyH⁺ salts. The complexes have been characterized through elemental analyses, spectral (u.v., vis., i.r.) properties, magnetic and conductance data. The structures of all those compounds have been proposed.     

Supramolecular cluster catalysis: facts and problems

By checking the chemistry underlying the concept of “supramolecular cluster catalysis” we identified two major errors in our publications related to this topic, which are essentially due to contamination problems. (1) The conversion of the “closed” cluster cation [H₃Ru₃(C₆H₆)(C₆Me₆)₂(O)]⁺ (1) into the “open” cluster cation [H₂Ru₃(C₆H₆)(C₆Me₆)₂(O)(OH)]⁺ (2), which we had ascribed to a reaction with water in the presence of ethylbenzene is simply an oxidation reaction which occurs in the presence of air. (2) The higher catalytic activity observed with ethylbenzene, which we had erroneously attributed to the “open” cluster cation [H₂Ru₃(C₆H₆)(C₆Me₆)₂(O)(OH)]⁺ (2), was due to the formation of RuO₂ · nH₂O, caused by a hydroperoxide contamination present in ethylbenzene.