Synthese,Strukturuntersuchung und Reaktionen Phosphansubstituierter Derivate von Fe3(CO)9(μ3-CF)2

Syntheses, Structure Determination and Reactions of Phosphine Substituted Derivatives of Fe₃(CO)₉(μ₃-CF)₂ Photolysis of Fe₃(CO)₉(μ₃-CF)₂ 1 in the presence of acetonitrile 2a or benzoenitrile 2b results in the substitution of a single carbonyl ligand by a nitrile ligand yielding Fe₃(CO)₈(CH₃CN)(μ₃-CF)₂ 3a and Fe₃(CO)₈(C₆H₅CN)(μ₃-CF)₂ 3b, respectively. The acetonitrile ligand in 3a can be easily replaced by trimethyl-phosphine 4a or triphenylphosphine 4b . The monosubstituted compounds Fe₃(CO)₈(PR₃)(μ₃-CF)₂5, R = CH₃ a, R = C₆H₅, b are obtained as major products besides a small amount of the disubsituted products Fe₃(CO)₇(PR₃)₂(μ₃-CF)₂ 6. The structure of 5a has been elucidated by a single crystal X-ray structure determination. Thermal ligand substitution in 1, however, results in the formation of a mixture of mono-, disubstituted, and trisubstituted products, in which 6b is the major product for diphenylphosphine. 5a reacts with ethyne 7 forming a phosphine substituted diferra-allyl-cluster Fe₃(CO)₇(PR₃)(μ₃-CF)(μ₃? CF? CH? CH) 8. The structure of one isomere of 8 has been determinated by X-ray crystallography.     

New Perspectives in Polyoxometalate Chemistry by isolation of compounds containing very large moieties as transferable building blocks: (NMe4)5[As2Mo8V4AsO40] · 3H2O, (NH4)21[H3Mo57V6(NO)6O183(H2O)18] · 65 H2O, (NH2Me2)18(NH4)6[Mo57V6(NO)6O183(H2O)18] · 14 H2O,and (NH4)12[Mo36(NO)4O108(H2O)16] · 33 H2O

The compounds (NMe₄)₅[As₂Mo₈V₄AsO₄₀] · 3 H₂O 2a , (NH₄)₂₁[H₃Mo₅₇V₆(NO)₆O₁₈₃(H₂O)₁₈] · 65 H₂O 3a , (NH₂Me₂)₁₈(NH₄)₆[Mo₅₇V₆(NO)₆O₁₈₃(H₂O)₁₈] · 14 H₂O 3b and (NH₄)₁₂[Mo₃₆(NO)₄O₁₀₈(H₂O)₁₆] · 33 H₂O 4a ( 3a and 4a were not correctly reported in the literature regarding to their composition, structures and the oxidation states of the metal centres) which contain large isolated anionic species, have been prepared (among them 3a, 3b , and 4a in rather high yield) and characterized by complete crystal structure analysis as well as IR/Raman, UV/VIS/NIR, ESR spectroscopy and magnetic susceptibility measurements, redox titrations, bond valence sum calculations, elemental analyses and thermogravimetric studies. Perspectives for polyoxometalate chemistry referring to the synthesis of “extremely” large nanoscaled species are discussed, together with the occurrence of a large transferable {Mo₁₇} building block in the compounds 3a, 3b and 4a which also exists in the corresponding iron compound Na₃(NH₄)₁₂[H₁₅Mo₅₇Fe₆(NO)₆O₁₈₃(H₂O)₁₈] · 76 H₂O 7a .     

Reactions of DI-η5-cyclopentadienyltricarbonyltriphenylphosphinediiron; an improved synthesis of the cyclopentadienylcarbonyliron tetramer

The compound (C₅H₅)₂Fe₂(CO)₃PPh₃, previously obtained by the photolysis of (C₅H₅)₂Fe₂(CO)₄ with PPh₃, may also be obtained by reflluxing these same reactants in benzene. The compound was isolated in pure form by means of low temperature column chromatography. It is unstable in solution in the absence of added PPh₃. Solid samples also are unstable over long periods of time. Decomposition in solution is complete within one hour at 80° yielding a mixture of (C₅H₅)₂Fe₂(CO)₄ and (C₅H₅)₄Fe₄(CO)₄. This reaction is suppressed by excess PPh₃. Heating a mixture of (C₅H₅)₂Fe₂(CO)₃PPh₃ and P(OEt)₃ gives a nearly quantitative yield of (C₅H₅)₂Fe₂(CO)₃P(OEt)₃. Refluxing a xylene solution of (C₅H₅)₂Fe₂(CO)₄ containing a slight molarr excess of PPh₃ for 7 h results in the isolation of (C₅H₅)₄Fe₄(CO)₄ in 56% yield, making this reaction by far the most convenient method for the preparation, in gram quantities, of this transition metal cluster.     

Acyl and α-Ketoacyl Complexes of Pt(II) with Weak Donor Ligands

Treatment of trans-Pt(COCOPh)(Cl)(PPh₃)₂ (1a) with AgBF₄in THF led to the formation of a metastatic complex trans-[Pt(COCOPh)(THF)(PPh₃)₂](BF₄) (2) which readily underwent ligand substitution to give a cationic aqua complex trans-[Pt(COCOPh)(OH₂)(PPh₃)₂](BF₄) (5a). Complex 5a has been characterized spectroscopically and crystallographically. Analogous reaction of trans-Pt(COCOOMe)(Cl)(PPh₃)₂ (1b) with Ag(CF₃SO₃) in dried CH₂C1₂ was found first to yield a methoxyoxalyl triflato complextrans-Pt(COCOOMe)(OTf)(PPh₃)₂ (6). Attempts to crystallize the triflato product in CH₂-cl₂hexane under ambient conditions also afforded an aqua complex of the triflate salt f/wu-[Pt(COCOOMe)(OH₂)(PPhj)₂](CF₃SO₃) (5b). Complex 5a in a noncoordinating solvent such as CH₂C1₂ or CHCl₃ suffered spontaneous decarbonylation to form first cis-[Pt(COPh)(CO)(PPh₃)₂l(BF₄) (3a) then the thermodynamically stable isomer trans-[Pt(COPh)(CO)(PPh₃)₂](BF₄) (3b). Crystallization of complex 3b under ambient conditions resulted in an aqua benzoyl complex trans-[Pt(COPh)(OH₂)(PPh₃)₂](BF₄) (7). The replacement of the H_2O ligand in complex 7 by CO was done simply by bubbling CO into the solution of 7. The single crystal structures of 5b and 7 have been determined by X-ray diffraction. The distances of the Pt-O bonds in 5a, 5b, and 7 support that the aqua ligand is a weak donor in such cationic aquaorganoplatinum(lI) complexes, in agreement with their lability to the substitution reactions.     

Zur Struktur und Reaktivität des Diammoniumhexafluoromanganats(IV)

About the Structure and Reactivity of Diammonium Hexafluoromanganate(IV) Electrolytic oxidation of an aqueous suspension of MnF₂ containing NH₄F, and subsequent crystallization in 40% HF yields yellow crystals of (NH₄)₂MnF₆. It crystallizes in the hexagonal K₂MnF₆ type structure with the space group P6₃mc and a = 5.903; c = 9.565 Å; Z = 2. With in situ powder diffraction studies it is shown, that (NH₄)₂MnF₆ is gradually reduced in a NH₃ atmosphere between 30 and 230 °C to afford (NH₄)₃MnF₆, (NH₄)₂MnF₅, and finally NH₄MnF₃. (NH₄)₃MnF₆, thereby, forms a hitherto unknown cubic (a = 9.082 Å) high temperature modification with the cryolite type structure. Under N₂ the thermal decomposition of (NH₄)₂MnF₆ proceeds via NH₄MnF₄ to yield MnF₂.     

Exploring the Reactivity of B-Connected Carboranylphosphines in Frustrated Lewis Pair Chemistry: A New Frame for a Classic System

The primary phosphines MesPH₂ and tBuPH₂ react with 9-iodo-m-carborane yielding B9-connected secondary carboranylphosphines 1,7-H₂C₂B₁₀H₉-9-PHR (R=2,4,6-Me₃C₆H₂ (Mes; 1 a ), tBu ( 1 b )). Addition of tris(pentafluorophenyl)borane (BCF) to 1 a , b resulted in the zwitterionic compounds 1,7-H₂C₂B₁₀H₉-9-PHR(p-C₆F₄)BF(C₆F₅)₂ ( 2 a , b ) through nucleophilic para substitution of a C₆F₅ ring followed by fluoride transfer to boron. Further reaction with Me₂SiHCl prompted a H−F exchange yielding the zwitterionic compounds 1,7-H₂C₂B₁₀H₉-9-PHR(p-C₆F₄)BH(C₆F₅)₂ ( 3 a , b ). The reaction of 2 a , b with one equivalent of R'MgBr (R’=Me, Ph) gave the extremely water-sensitive frustrated Lewis pairs 1,7-H₂C₂B₁₀H₉-9-PR(p-C₆F₄)B(C₆F₅)₂ ( 4 a , b ). Hydrolysis of the B−C₆F₄ bond in 4 a , b gave the first tertiary B-carboranyl phosphines with three distinct substituents, 1,7-H₂C₂B₁₀H₉-9-PR(p-C₆F₄H) ( 5 a , b ). Deprotonation of the zwitterionic compounds 2 a , b and 3 a , b formed anionic phosphines [1,7-H₂C₂B₁₀H₉-9-PR(p-C₆F₄)BX(C₆F₅)₂]⁻[DMSOH]⁺ (R=Mes, X=F ( 6 a ), R=tBu, X=F ( 6 b ); R=Mes, X=H ( 7 a ), R=tBu, X=H ( 7 b )). Reaction of 2 a , b with an excess of Grignard reagents resulted in the addition of R’ at the boron atom yielding the anions [1,7-H₂C₂B₁₀H₉-9-PR(p-C₆F₄)BR’(C₆F₅)₂]⁻ (R=Mes, R’=Me ( 8 a ), R=tBu, R’=Me ( 8 b ); R=Mes, R’=Ph ( 9 a ), R=tBu, R’=Ph ( 9 b )) with [MgBr(Et₂O)_n]⁺ as counterion. The ability of the zwitterionic compounds 3 a , b to hydrogenate imines as well as the Brønsted acidity of 3 a were investigated.     

Synthesis and Ionic Conductivity of Lithium-conducting Titanium Phosphate Solid Electrolytes

Solid electrolytes were synthesized in the systems Li₂O-Al₂O₃-TiO₂-P₂O₅ and Li₂O-Al₂O₃-TiO₂-P₂O₅-H₂O-H₂O₂. Their ionic conductivities were studied and compared. The possibility of obtaining a film of Li_{1 . 3}Al_{0 . 3}Ti_{1 . 7}(PO₄)₃ solid electrolyte on a sapphire substrate from an aqueous peroxide solution of a precursor was analyzed.     

Preparation and characterization of M(CH3)5 (M = Nb or Ta) and Ta(CH2C6H5)5 and evidence for decomposition by α-hydrogen atom abstraction

The preparations of Nb(CH₃)₅, Ta(CH₃)₅, and Ta(CH₂C₆H₅)₅ are reported in detail. The M(CH₃)₅ complexes decompose autocatalytically to give 3.4 ± 0.1 mol of methane and a non-hyclrolyzable residue with approximate composition MC_1–5H while Ta(CH₂C₆H₅)₅ decomposes in a non-autocatalytic manner to give ca. 2.6 mol of toluene per Ta. Decomposition of Nb(CD₃)₅ gave 96% CD₄ in diethyl ether while the toluene produced on decomposition of Ta(CD₂C₆H₅)₅ was at least 90%-d₃. An observed kinetic deuterium isotope effect of 2–3 in each case is evidence that an α-CH(D) bond is broken in a slow step of the decomposition. It is postulated that M(CH₃)₅ and Ta(CH₂C₆H₅)₅ decompose primarily by α-hydrogen atom abstraction though almost certainly in a complex, possibly intermolecular fashion in the case of M(CH₃)₅. In neither case (R = CH₃ or CH₂C₆H₅) was there evidence for significant homolytic cleavage of the metalcarbon bond to give free alkyl radicals.     

Piperazine Functionalization of C70 for Incorporation into Supramolecular Assemblies

The photochemical reaction of piperazine with C₇₀ produces a mono‐adduct (N(CH₂CH₂)₂NC₇₀) in high yield (67 %) along with three bis‐adducts. These piperazine adducts can combine with various Lewis acids to form crystalline supramolecular aggregates suitable for X‐ray diffraction. The structure of the mono‐adduct was determined from examination of the adduct I₂N(CH₂CH₂)₂NI₂C₇₀ that was formed by reaction of N(CH₂CH₂)₂NC₇₀ with I₂. Crystals of polymeric {Rh₂(O₂CCF₃)₄N(CH₂CH₂)₂NC₇₀}_n?nC₆H₆ that formed from reaction of the mono‐adduct with Rh₂(O₂CCF₃)₄ contain a sinusoidal strand of alternating molecules of N(CH₂CH₂)₂NC₇₀ and Rh₂(O₂CCF₃)₄ connected through Rh?N bonds. Silver nitrate reacts with N(CH₂CH₂)₂NC₇₀ to form black crystals of {(Ag(NO₃))₄(N(CH₂CH₂)₂NC₇₀)₄}_n?7nCH₂Cl₂ that contain parallel, nearly linear chains of alternating (N(CH₂CH₂)₂NC₇₀ molecules and silver ions. Four of these {Ag(NO₃)N(CH₂CH₂)₂NC₇₀}_n chains adopt a structure that resembles a columnar micelle with the ionic silver nitrate portion in the center and the nearly non‐polar C₇₀ cages encircling that core. Of the three bis‐adducts, one was definitively identified through crystallization in the presence of I₂ as ¹²{N(CH₂CH₂)₂N}₂C₇₀ with addends on opposite poles of the C₇₀ cage and a structure with C_2v symmetry. In ¹²{I₂N(CH₂CH₂)₂N}₂C₇₀, individual ¹²{I₂N(CH₂CH₂)₂N}₂C₇₀ units are further connected by secondary I2???N2 interactions to form chains that occur in layers within the crystal. Halogen bond formation between a Lewis base such as a tertiary amine and I₂ is suggested as a method to produce ordered crystals with complex supramolecular structures from substances that are otherwise difficult to crystallize.     

[(Ph3Sn)3VO4]·CH3CN und [(Ph3Sn)3VO4]·2 DMF,Triphenylzinnvanadate mit neuartigen Kettenstrukturen

[(Ph₃Sn)₃VO₄]·CH₃CN and [(Ph₃Sn)₃VO₄]·2 DMF, Triphenyltin Vanadates with Novel Chain Structures The reaction of Na₃VO₄ with Ph₃SnCl in a water/CH₂Cl₂ mixture leads to the formation of [(Ph₃Sn)₃VO₄] ( 1 ). Recrystallization of 1 from toluene/CH₃CN gives pale yellow crystals of [(Ph₃Sn)₃VO₄]·CH₃CN ( 2 ). 2 crystallizes as coordination polymer which consists of infinite chains composed of corner‐sharing VO₄ tetrahedra and Ph₃SnO₂ trigonal bipyramides. Additionally the VO₄ groups are connected to two terminal SnPh₃‐Groups containing tin atoms in a tetrahedral environment. [(Ph₃Sn)₃VO₄]·2 DMF ( 3 ) which is obtained from Na₃VO₄ and Ph₃SnCl in a water/DMF mixture contains a polymeric chain structure similar to 2 and additionally one of the terminal SnPh₃ groups is coordinated to a DMF solvent molecule.     

Novel Cu–Te Clusters Synthesised from tBuTeSiMe3: [Cu18Te6(TetBu)6(PPh2Et)7], [Cu19Te6(TetBu)7(PEt3)8], [Cu27Te15(PiPr2Me)12] and [Cu58Te32(PtBu2nBu)14]

The reactions of CuCl and tBuTeSiMe₃ in the presence of phosphine ligands result in the formation of four new Cu/Te cluster complexes, [Cu₁₈Te₆(TetBu)₆(PPh₂Et)₇], [Cu₁₉Te₆(TetBu)₇(PEt₃)₈], [Cu₂₇Te₁₅(PiPr₂Me)₁₂] and [Cu₅₈Te₃₂(PtBu₂ nBu)₁₄], which have been structurally characterized by single crystal structural analysis. The former two clusters show a layer-type tellurium frameworks in which the copper atoms are asymmetrically spread. The latter two clusters possess a tellurium framework in a body-centered Te₁₄-Frank-Kasper polyhedron or a Te₂₈ polyhedron with four interstitial tellurium atoms and belong to mixed-valence Cu/Te compounds.     

Synthesis and structural analysis of nonstoichiometric ternary fulleride K 1.5 Ba 0.25 CsC 60

The existence of cation-vacancy sites in fullerides might lead to long-range ordering and generate a new vacancy-ordered superstructure. The purpose of this work is to search whether or not long-range ordering of vacant tetrahedral sites, namely superstructure emerges in nonstoichiometric K _1.5 Ba _0.25 CsC ₆₀ fulleride. Therefore, K _1.5 Ba _0.25 CsC ₆₀ with cation-vacancy sites is synthesized using a precursor method to avoid inadequate stoichiometry control and formation of impurity phases within the target composition. For this purpose, first, phase-pure K ₆ C ₆₀ , Ba ₆ C ₆₀ and Cs ₆ C ₆₀ precursors are synthesized. Stoichiometric quantities of these precursors are used for further reaction with C ₆₀ to afford K _1.5 Ba _0.25 CsC ₆₀ . Rietveld analysis of the high-resolution synchrotron X-ray powder diffraction data of the precursors and K _1.5 Ba _0.25 CsC ₆₀ confirms that K ₆ C ₆₀ , Ba ₆ C ₆₀ and Cs ₆ C ₆₀ are single-phase and they crystallize in a body-centered-cubic structure ( Im 3) as reported in the literature. The analysis also shows that K _1.5 Ba _0.25 CsC ₆₀ phase can be perfectly modeled using a face-centered cubic structure. No new peaks appear which could have implied the appearance of a superstructure. This suggests that there is no long-range ordered arrangement of vacant tetrahedral sites in K _1.5 Ba _0.25 CsC ₆₀ .     

Linking Chiral Clusters with Molybdate Building Blocks: From Homochiral Helical Supramolecular Arrays to Coordination Helices

The synthesis of four new oxo‐centered Fe clusters ( 1 a – c , 2 ) of the form [Fe^III₃(μ₃‐O)(CH₂=CHCOO)₆] with acrylate as the bridging ligand gives rise to potentially intrinsically chiral oxo‐centered {M₃} trimers that show a tendency to spontaneously resolve upon crystallization. For instance, 1 a , [Fe^III₃(μ₃‐O)(CH₂=CHCOO)₆‐(H₂O)₃]⁺, crystallizes in the chiral space group P3₁ as a chloride salt. Crystallization of 1 b , [Fe₃(μ₃‐O)(C₂H₃CO₂)₆(H₂O)₃]NO₃?4.5H₂O, from aqueous solution followed by recrystallization from acetonitrile also gives rise to spontaneous resolution to yield the homochiral salt [Fe₃(μ₃‐O)(C₂H₃CO₂)₆‐(H₂O)₃]NO₃?CH₃CN of 1 c (space group P2₁2₁2₁). Furthermore, the reaction of 1 a with hexamolybdate in acetonitrile gives the helical coordination polymer {[(Fe₃(μ₃‐O)L₆(H₂O))(MoO₄)‐(Fe₃(μ₃‐O)L₆(H₂O)₂)]?2CH₃CN?H₂O}_∞ 2 (L: H₂C?CHCOO), which crystallizes in the space group P2₁. The nature of the ligand geometry allows the formation of atropisomers in both the discrete ( 1 a – c ) and linked {Fe₃} clusters ( 2 ), which is described along with a magnetic analysis of 1 a and 2 .     

The dimerization of diphenyl(cyclopentadienyl)phosphine ligands by Diels-Alder addition

Reaction of diphenyl(cyclopentadienyl)phosphine, 1, with [PdCl₂(PhCN)₂], [PtCl₂(SMe₂)₂] or [M(CO)₄(norbornadiene)], where M = Mo or W, gave the complexes [PdCl₂{(Ph₂P)₂C₁₀H₁₀}], [PtCl₂{(Ph₂P)₂C₁₀H₁₀}] or [M(CO)₄{(Ph₂P)₂C₁₀H₁₀}] respectively, in which the ligand underwent dimerization by Diels-Alder addition. The reaction occurs in a very selective way and this is rationalized in terms of a template effect, in which two ligands 1 in mutually cis positions undergo the Diels-Alder reaction. In contrast, the complex [Fe(CO)₄(Ph₂PC₅H₅)] is stable to Diels-Alder addition. The structures of the complexes were deduced by ¹H, ¹³C and ³¹P NMR spectroscopy. The major product contains a six-membered chelate ring while a minor product, formed in the palladium and platinum systems only, contains a five-membered chelate ring.     

New cyclic phosphonium salts derived from the reaction of phosphine-aldehydes with acid

Various cyclic phosphonium structures are formed in high yield by the deprotection of unstable phosphine-aldehydes in acidic solution. When there is a methylene spacer between the phosphine and the aldehyde, a phosphonium ion [PHR₂CH₂CH(OEt)₂]Br₂, R=iPrOH, Et is obtained. Reaction of these phosphonium salts with water produces the dimers [-PR₂CH₂CH(OH)-]₂[Br]₂ R = iPr, Et. When there is an ethylene spacer as in PPh₂CH₂CH₂CH(OCH₂CH₂O), a remarkable tetramer with a 16-membered ring [-PPh₂CH₂CH₂CH (OH)-]₄[Cl]₄ forms as one diastereomer in hydrochloric acid solution. Reaction of HCl with the protected phosphine-aldehyde with a propylene spacer (PPh₂CH₂CH₂CH₂CH(OCH₂CH₂O)) results in the formation of the monomeric phosphonium salt [-PPh₂ CH₂CH₂CH₂CH(OH)-]Cl with a 5-membered ring. Solid state structures of different ring types were determined using X-ray diffraction experiment.     

As12Se44—: ein neuartiges Selenoarsenatanion mit einem Polyarsenkäfig in der Verbindung [Co(NH3)6]2As12Se4 · 12 NH3

As₁₂Se₄^4—: a New Selenoarsenate Anion with a Polyarsenic Cage in the Compound [Co(NH₃)₆]₂As₁₂Se₄ · 12 NH₃ Orange coloured crystals of [Co(NH₃)₆]₂As₁₂Se₄ · 12 NH₃ were prepared by the reduction of As₄Se₄ with a solution of sodium in liquid ammonia and subsequent precipitation with CoBr₂. The X‐ray structure determination shows them to contain the selenoarsenate anion As₁₂Se₄^4—, which consists of a central As₁₂‐cage with four exo‐bonded, formally negatively charged Se atoms. The structure of the As₁₂‐cage is equivalent to the main polyphosphorus building unit of a known organopolyphosphane and of tubular P₁₂ in the compound (CuI)₃P₁₂.     

Reduction of the titanium niobium oxides. I. TiNb2O7 and Ti2Nb10O29

Reduction of the titanium-niobium oxides follows a common pattern. TiO₂ is eliminated, to form a new phase richer in titanium than the original compound, and Nb(iv) replaces Ti(iv) in the original block structure, which is thereby enriched in niobium. With TiNb₂O₇, the second phase is a TiO₂NbO₂ solid solution, with the rutile structure, initially with a high titanium content, in equilibrium with a solid solution of composition Me₃O₇, isostructural with TiNb₂O₇. At log p_O2 (atm) about ?9.0 this reaches the limiting composition Ti_0.72Nb_2.28O₇, in equilibrium with Ti_0.56Nb_0.44O₂. The Me₃O₇ block structure then transforms into the Me₁₂O₂₉ block structure (Ti₂Nb₁₀O₂₉Nb₁₂O₂₉ solid solution), which rapidly increases in niobium content as reduction continues. Reduction of Ti₂Nb₁₀O₂₉ at oxygen fugacities above log p_O2 (atm) = ?9.0 forms the Me₃O₇ phase as the titanium-rich phase. At log p_O2 = ?9.0, and a composition about Ti_1.6Nb_10.4O₂₉, the rutile solid solution takes over as second phase. The niobium/titanium ratio in both phases rises as reduction proceeds, and the last vestiges of the Me₁₂O₂₉ phase, in equilibrium with the final product, Ti_0.17Nb_0.67O₂, are almost denuded of titanium.     

Synthesis,structure, and properties of compounds containing both octahedral rhenium cluster cations and anions

The compound [{Re₆S₈}(3,5-Me₂pzH)₆]₂[{Re₆S₈}Br₆]?9H₂O?4EtOH containing a cluster cation and a cluster anion in a 2: 1 ratio was synthesized by mixing an ethanol solution of the rhenium cluster complex [{Re₆S₈}(3,5-Me₂pzH)₆]Br₂?2(3,5-Me₂pzH) (pzH is pyrazole) with an aqueous solution of Cs₄[{Re₆S₈}Br₆]?2H₂O. The resulting compound was characterized by a combination of physicochemical methods. In particular, luminescence properties were studied and compared with those of the parent cluster complexes. A crystal suitable for single-crystal X-ray diffraction was obtained by layering these solutions. According to single-crystal X-ray diffraction analysis, this compound is composed of a cluster cation and a cluster anion (in a ratio of 1: 1) and also of Zundel cations (H₅O₂ ⁺) and solvate water molecules and is described by the formula (H₅O₂)₂[{Re₆S₈}(3,5-Me₂pzH)₆][{Re₆S₈}Br₆]?4H₂O.     

Thiochloroarsenate(III): Darstellung,Schwingungsspektren und Kristallstrukturen von PPh4[As2SCl5] und (PPh4)2[As2SCl6] · C2H4Cl2

Thiochloroarsenates (III): Preparation, Vibrational Spectra, and Crystal Structures of PPh₄[As₂SCl₅] and (PPh₄)₂[As₂SCl₆] · C₂H₄Cl₂ PPh₄[As₂SCl₅] can be obtained from As₂S₃ + PPh₄Cl with HCl in CH₂Cl₂ or 1,2-C₂H₄Cl₂. It reacts with a second mole of PPh₄Cl to yield (PPh₄)₂[As₂SCl₆]. The latter also is formed by the reaction of As₂S₅ + 2 PPh₄Cl with HCl, a second product being (PPh₄)₂[As₂Cl₈]. The i.r. and Raman spectra of the title compounds are reported. Their crystal structures were determined by X-ray diffraction. Crystal data: PPh₄[As₂SCl₅], monoclinic, space group P2₁/n, a = 1175.8, b = 1508.0, c = 1593.4 pm, β = 96.22°, Z = 4; (PPh₄)₂[As₂SCl₆] · C₂H₄Cl₂, triclinic, P1, a = 1166.3, b = 1188.2, c = 2044.6 pm, α = 95.47, β = 97.53, γ = 111.05°, Z = 2. Including the lone electron pairs, the coordination of the As atoms in the [As₂SCl₅]⁻ ion is distorted trigonal-bipyramidal with the S, one Cl atom, and an electron pair in equatorial positions; the two bipyramids around the two As atoms share a common edge. The As atoms in the [As₂SCl₆]²⁻ ion have a distorted octahedral coordination, the two octahedra share a common face; the lone electron pairs are in the trans positions to the S atom.     

Bildung siliciumorganischer Verbindungen. 70 [1]. Reaktionen Si-fluorierter 1,3,5-Trisilapentane mit CH3MgCl und LiCH3

Formation of Organosilicon Compounds. 70. Reactions of Si-fluorinated 1,3,5-Trisilapentanes with CH₃MgCl and LiCH₃ F₃Si? CCl₂? SiF₂? CH₂? SiF₃ 3 reacts with meMgCl. (me = Ch₃ starting with a Si-methylation and not with a C-metallation as in the corresponding Si- and C-chlorinated compounds, e. g. (Cl₃Si? CCl₂)₂SiCl₂ [2]. A CCl-hydrogenation is observed too, which in the case of F₃Si? CCl₂? SiF₂? CHCl? SiF₃ 4 gives meS₃Si? CCl₂? Sime₂? CH₂? Sime₃. (F₃Si? CCl₂)_{2 5} reacts with meMgCl to form preferentially 1,2-Disilapropanes by cleaving a Si? Cbond. The isolation of F₃Si? CCl₂H and meF₂Si? CCl₂? SiF₂me allows to locate the bond where 5 is cleaved at the beginning of the reaction. With meLi 5 reacts to form mainly me₃Si? C?C? Sime₃, showing that in the reaction of meLi, being a stronger reagent than meMgCl, and 5 a C-metallation occurs, following the same mechanism as in the reaction with (Cl₃Si? CCl₂)₂)SiCl₂ [2]. The reaction conditions for the synthesis of Si-fluroinated and C-chlorinated 1,3,5-Trisilapentanes in a 0.1 mol scale are reported. N.m.r. data of all investigated compounds are tabulated.