Synthesen und Kristallstrukturen neuer selenidoverbrückter Ruthenium-Clusterverbindungen

Syntheses and Crystal Structures of New Selenido-bridged Ruthenium Clusters The reaction of Se(SiMe₃)₂ with [RuCl₂(PPh₃)₃], or a mixture of [RuCl₂(PPh₃)₃] and alkylphosphines leads to the formation of selenido-bridged ruthenium clusters. In this publication the compounds [Ru₆Se₈(PPh₃)₆] ( 1 ), [Ru₆Se₈(PEt₃)₆] ( 2 ) und[Ru₆Se₈(PⁿPr₃)₆] ( 3 ) are described.The compounds 1-3 contain Ru₆¹⁶⁺ cluster cores with Ru²⁺ and Ru³⁺ centers. The structures of these compounds were elucidated by single crystal X-ray structural analyses.     

Syntheses,structures, and optical properties of heteroselenometallic W–Se–Ag polymer compounds {[Et4N][(μ-WSe4)Ag]}n and {[Ln(Me2SO)8][(μ3-WSe4)3Ag3]}n (Ln = Pr,Er)

The one-dimensional linear polymer W–Se–Ag compound {[Et₄N][(μ-WSe₄)Ag]}_n (1) was obtained from the reaction of [Et₄N]₂[WSe₄] and AgNO₃ in a mixed solvent, MeCN/DMF (1:10). Treatment of a solution of 1 in Me₂SO with Ln(NO₃)₃ · 6H₂O resulted in the formation of a helical chain polymer compound {[Ln(Me₂SO)₈][(μ₃-WSe₄)₃Ag₃]}_n (Ln = Pr 2, Er 3). The solid-state structures of the three polymer compounds 1, 2, and 3 have been established by X-ray crystallography. The third-order non-linear optical properties of the linear polymer compound 1 were determined by z-scan techniques with 7 ns pulses at 532 nm.     

Metallorganische Verbindungen der Lanthanoide. 113. [(tert-Butylcyclopentadienyl)(cyclopentadienyl)dimethylsilan]-Komplexe ausgewählter Lanthanoide

Organometallic Compounds of the Lanthanides. 113. [(tert-Butylcyclopentadienyl)(cyclopentadienyl)dimethylsilane] Complexes of selected Lanthanides The reaction of [Me₂Si(C₅H₄)(tBuC₅H₃)]Li₂ with LnCl₃ (Ln = Y, Nd, Sm, Lu) in THF results in the formation of the chiral, dimeric complexes [Me₂Si(C₅H₄)(tBuC₅H₃)]Ln(μ-Cl)₂Li(THF)(Et₂O) [Ln = Y ( 1 ), Nd ( 2 ), Sm ( 3 ), Lu ( 4 )]. The ¹H-, ¹³C-NMR- and the mass spectra of the new compounds as well as the X-ray crystal structures of 2 a and 3 a were discussed.     

Preparation and reactivity of the heterobimetallic ReIr face-shared bioctahedral compounds Cp*Ir(μ-Cl)3Re(CO)3 and Cp*Ir(μ-SC6H4Me-4)3Re(CO)3: X-ray diffraction structures and redox behavior

Thermolysis of the dinuclear compound [Cp*IrCl₂]₂ (1) with ClRe(CO)₅ (2) leads to the formation of the confacial bioctahedral compound Cp*Ir(μ-Cl)₃Re(CO)₃ (3) in high yield. Whereas the substitution of the chloride ligands in 3 is observed on treatment with excess p-methylbenzenethiol to furnish the sulfido-bridged compound Cp*Ir(μ-SC₆H₄Me-4)₃Re(CO)₃ (4), 3 undergoes fragmentation upon reaction with tertiary phosphines [PPh₃ and P(OMe)₃] to furnish the mononuclear compounds Cp*IrCl₂P and fac-ClRe(CO)₃P₂. Both 3 and 4 have been isolated and fully characterized in solution by IR and ¹H NMR spectroscopies, and their solid-state structures have been established by X-ray crystallography. The redox properties of 3 and 4 have been explored by cyclic voltammetry, and the results are discussed relative to extended Hückel MO calculations.     

Synthesis of neutral and cationic monocyclopentadienyl alkyl niobium and tantalum complexes

Compound [NbCp′Me₄] (Cp′ = η⁵-C₅H₄SiMe₃, 1) reacted with several ROH compounds (R = tBu, SiiPr₃, 2,6-Me₂C₆H₃) to give the derivatives [NbCp′Me₃(OR)] (R = tBu 2a, SiiPr₃2b, 2,6-Me₂C₆H₃2c). The diaryloxo tantalum compound [TaCp^∗Me₂(OR)₂] (Cp^∗ = η⁵-C₅Me₅, R = 2,6-Me₂C₆H₃3) was obtained by reaction of [TaCp^∗Cl₂Me₂] with 2 equiv of LiOR (R = 2,6-Me₂C₆H₃). Abstraction of one methyl group from these neutral compounds 1-3 with the Lewis acids E(C₆F₅)₃ (E = B, Al) gave the ionic derivatives [NbCp′Me₂X][MeE(C₆F₅)₃] (X = Me 4-E. X = OR; R = SiiPr₃5b-E, 2,6-Me₂C₆H₃5c-E. E = B, Al) and [TaCp^∗Me(OR)₂][MeE(C₆F₅)₃] (R = 2,6-Me₂C₆H₃6-E; E = B, Al). Polymerization of MMA with the aryloxoniobium compound 2c and Al(C₆F₅)₃ gave syndiotactic PMMA in a low yield, whereas the tetramethylniobium compound 1 and the diaryloxotantalum derivative 3 were inactive.     

Synthesis and characterization of new strontium 4-carboxyphenylphosphonates

Several new strontium 4-carboxyphenylphosphonates, i.e., two modifications of Sr(HOOCC₆H₄PO₃H)₂, SrH(OOCC₆H₄PO₃)·H₂O, Sr₃(OOCC₆H₄PO₃)₂·4H₂O and Sr₃(OOCC₆H₄PO₃)₂·5.7H₂O were prepared and characterized by elemental analysis, thermogravimetry, X-ray powder diffraction and infrared spectroscopy. It was found that the compositions of these compounds depend on the acidity of the reaction medium. In addition, the presented compounds are interconvertible in dependence on pH. The position of the acid hydrogen atom in SrH(OOCC₆H₄PO₃)·H₂O was determined from the IR spectra of the studied compounds.The structure of the β modification of Sr(HOOCC₆H₄PO₃H)₂ was solved from its X-ray powder diffraction pattern using an ab initio method (the FOX program) with subsequent Rietveld refinement in the FULLPROF program. The compound is monoclinic, with the space group P2₁/c (No. 14), a=49.88(2), b=7.867(2), c=5.602(3) Å, β=128.68(2)°, and Z=4. It has a one-dimensional structure with an inorganic part built of SrO₈ distorted tetragonal antiprisms.     

Organoelement compounds in the electrochemical synthesis of fluoroorganics

Electrochemical generation of organic anion-radicals in the presence of fluoroorganosilanes causes the chain addition reaction. Adducts of CFCl₂SiMe₃, CFClCFSiMe₃ and CF₃SiMe₃ with benzaldehyde were obtained with conversion efficiency up to 8000%.Electroreduction of bis-(trifluoromethyl)mercury (II) was established to be the route for the intermediate formation of trifluoromethyl anion, which was trapped by the reactions with benzaldehyde, Me₃SiCl and bromobenzonitrile.The use of salen Ni(II) complex as mediator allows the electrochemical reduction of polyfluoroalkylchlorides at the potentials more than 1 V higher than their reduction potentials.     

Halogenid‐Ionen als Katalysator: Metallzentrierte C–C‐Bindungsknüpfung ausgehend von Acetontril

Halide Ions as Catalyst: Metalcentered C–C Bond Formation Proceeded from Acetonitril AlMe₃ reacts at 20 ?C in acetonitrile to the complex [Me₃Al(NCMe)] ( 1 ). By addition of cesium halides (X^– = F^–, Cl^–, Br^–) a trimerisation to the heterocycle [Me₂Al{HNC(Me)}₂C(CN)] ( 2 ) has been observed. The reaction might be carried out under catalytic conditions (1–2 mol% CsX). The gallium complex [Me₂Ga{HNC(Me)}₂ · C(CN)] ( 3 ), generated under similar reaction conditions, can be converted to the silylated compound [Me₂Ga{Me₃SiNC(Me)}₂C(CN)] ( 4 ) by successive treatment with two equivalents n‐butyllithium and Me₃SiCl. 3 reacts under hydrolysis conditions (1 M hydrochloric acid) to the iminium salt [{H₂NC(Me)}₂C(CN)]Cl ( 5 ). A mixture of H₂O, Ph₂PCl and 3 in THF/toluene leads in a unusual conversion to the diphospane derivative [Ph₂P–P(O)(Me₂GaCl)] ( 6 ). 1 , 2 , 4 , 5 and 6 have been characterized by NMR, IR and MS techniques. X‐ray structure analyses were performed with 1 , 2 , 4 and 6 · 0.5 toluene. According this 1 possesses an almost linear axis AlNCC [Al1–N1–C3: 179,5(2)?; N1–C3–C4: 179,7(4)?]. 2 is an AlN₂C₃ six‐membered heterocycle with two iminium fuctions. One N–H group is responsible for a intermolecular chain‐formation through hydrogen bridges to an adjacent nitrile group along the direction [010]. The basic structural motif of the heterocycle 3 has been maintained after silylation to 4 . In 6 · 0.5 toluene an unit Me₂GaCl, originated from 3 , is coordinated to the oxygen atom of the diphosphane oxide Ph₂P–P(O)Ph₂.     

Darstellung,Eigenschaften und Kristallstruktur von RuSn6[(Al1/3–xSi3x/4)O4]2 (0 ≤ x ≤ 1/3) – einem Oxid mit isolierten RuSn6‐Oktaedern

Preparation, Properties, and Crystal Structure of RuSn₆[(Al_1/3–xSi_3x/4)O₄]₂ (0 ≤ x ≤ 1/3) – an Oxide with isolated RuSn₆ Octahedra RuSn₆[(Al_1/3–xSi_3x/4)O₄]₂ is obtained by the solid state reaction of RuO₂, SnO₂, Sn, and Si in an Al₂O₃‐crucible at 1273 to 1373 K. The compound is cubic with the space group Fm 3 m (a = 9.941(1) Å, Z = 4, R₁ = 0.0277, wR₂ = 0.0619), a semiconductor and stable in air. Results of Mößbauer measurements as well as bond length‐bond strength calculations justify the ionic formulation Ru²⁺Sn₆²⁺[(Al_1/3–x³⁺Si_3x/4⁴⁺)O₄^2–]₂. The central motif of the crystal structure are separated RuSn₆‐octahedrea. These are interconnected by oxygen atoms, arranged tetrahedrely above the surfaces of the RuSn₆‐octahedrea and partialy filled with Al and Si, respectively. Because of these features the compound can be considered as a variant of the crystal structure type of pentlandite.     

[PbAsSiiPr3]6 — the First Structurally Characterized Compound with Chemical Bonds between Lead and Arsenic

The compound [PbAsSiiPr₃]₆ ( 1 ) could be obtained by the reaction of PbCl₂ with iPr₃SiAs(SiMe₃)₂ in THF at 0 °C. Central structural motif is a hexagonal prism built by six lead and six arsenic atoms. The average Pb—As bond length is 281 pm. The cluster crystallizes in the monoclinic space group C2/c, the lattice constants are: a = 4460.8(9) b = 2296.6(5), c = 2734.4(6) pm, β = 117.57(3)°. The thermogravimetric analysis in vacuum shows the tendecy of 1 to decompose under formation of elementary lead and volatile arsenic compounds.     

Zwei- und dreikernige Komplexe des WS42– mit Tricarbonylrhenium(I)- und -mangan(I)-Fragmenten: Struktur,Spektroskopie und Elektrochemie

Di- and Trinuclear Complexes of WS₄^2– with Tricarbonylrhenium(I) and -manganese(I) Fragments: Structure, Spectroscopy, and Electrochemistry The reaction of (NEt₄)₂WS₄ with two equivalents of M(CO)₅(O₃SCF₃), M = Mn or Re, in acetonitrile yielded the crystallographically characterized neutral compounds [(CH₃CN)(OC)₃M(μ-S₂WS₂)M(CO)₃(NCCH₃)]. The individual molecules are chiral and contain WS₄ and MS₂(CO)₃(CH₃CN) moieties in approximately tetrahedral and octahedral configurations, respectively. Vibrational and electronic absorption spectra are in agreement with the crystal structure, comparable results were obtained for trinuclear complexes [(L)(OC)₃Re(μ-S₂WS₂)Re(CO)₃(L)](NEt₄)₂, L = Cl^– or CN^–, and for the dinuclear systems [(WS₄)Re(CO)₃(CH₃CN)](NEt₄) and [(WS₄)Re(CO)₃Cl](NEt₄)₂. Electrochemical processes are irreversible due to the lability of acetonitrile or chloride ligands in corresponding complexes, however, the cyanide compound [(NC)(OC)₃Re(μ-S₂WS₂)Re(CO)₃(CN)]^2– showed reversible one-electron reduction to a first tetrathiotungstate(V) species as detected by UV/Vis/IR spectroelectrochemistry.     

Untersuchungen zur Sb–Sb‐Bindungsknüpfung in der Koordinationssphäre von Übergangsmetallen

Investigations of Sb–Sb Bond Formation Reactions in the Coordination Sphere of Transition Metals The reaction of SbCl₃ with various transition metal metalates of the type K[ML_n] [ML_n = Ni(CO)Cp*, Fe(CO)Cp′, Co(CO)₄; Cp* = η⁵‐C₅Me₅, Cp′ = η⁵‐C₅H₄Me] in the presence of [Cr(CO)₅thf] have been studied. With K[Ni(CO)Cp*] and K[Fe(CO)₂Cp′] the trigonal‐pyramidal complexes [(μ₃‐Sb){Ni(CO)Cp*}₃] ( 1 ) and [(μ₃‐Sb){Fe · (CO)₂Cp′}₃] ( 2 ), respectively, are obtained. The reaction with K[Co(CO)₄] leads to the tetrahedral cluster [Co₃(CO)₉(μ₃‐Sb{Cr(CO)₅})] ( 3 ) and the butterfly cluster [Co₂(CO)₆(μ‐SbCl)(μ‐SbCl{Cr(CO)₅})] ( 4 ). All products are characterised by X‐ray crystal structure determination. In contrast to the corresponding [(CO)₅CrPCl₃] system forming P–P bonds, starting from SbCl₃/[Cr(CO)₅thf] does not cause a Sb–Sb bond formation.     

Effect of chain length on the formation of intramolecular and intermolecular products: Reaction of diols with cyclotriphosphazene

The reactions of cyclotriphosphazene, N₃P₃Cl₆ (1), in a 1:1.2 stoichiometry with the sodium derivative of seven diols [ethane- (2a), 1,3-propane- (2b), 1,4-butane- (2c), 1,5-pentane- (2d), 1,6-hexane- (2e), 1,8-octane- (2f) and 1,10-decane- (2g) diol] in THF solution at room temperature have been used to investigate the effect of chain length on the formation of reaction products. Although no new products were found for the reaction of 1 with diols 2a-c compared to those in the literature using other bases and solution conditions, the reactions of 1 with the diols 2d-g gave six different types of products, whose structures have been characterized by elemental analysis, mass spectrometry, ¹H and ³¹P NMR spectroscopy; ansa compounds N₃P₃Cl₄[O(CH₂)_nO], (5d-5g); single-bridged compounds N₃P₃Cl₅[O(CH₂)_nO]N₃P₃Cl₅(6d-6f); double-bridged compounds N₃P₃Cl₄[O(CH₂)_nO]₂N₃P₃Cl₄ (7d-7g, syn and anti) and triple-bridged compounds, N₃P₃Cl₃[O(CH₂)_nO]₃N₃P₃Cl₃ (8d-f). Where suitable single crystals were obtained, X-ray crystallographic studies confirmed the structures of two ansa compounds (5d and 5f), one single-bridged compound (6e), and five double-bridged compounds (meso-anti for 7d, 7e, 7f and meso-syn for 7d and 7f). ³¹P NMR measurements of the reaction mixtures were used to quantify the formation of products for the reactions 1 with all the diols, 2a-g; it is found that, with increasing chain length of the diol, there is a decrease in the products formed by intramolecular reactions (spiro and ansa derivatives) and a concomitant increase in the amounts of products formed by intermolecular reactions (single-, double- and triple-bridged derivatives) of cyclophosphazene.     

Preparation of Acyclic and Heterocyclic Tellurathianitrogen Compounds: Contributions to a Better Understanding of Complex Reaction Pathways

Reactions between Cl₃S₃N₃ and TeCl₄ provide [S₄N₃⁺][Te₂Cl₉^‐] and [ ][TeCl₅^‐], the latter molecule, for the first time in SN‐chemistry, contains a five membered ring with three nitrogen atoms linked to each other. The course of this unusual reaction is discussed and both structures are proved by X‐ray structure determinations. New routes to the known cages (XTeNSN)₃N (X = F, Cl) result from the decomposition of X₂Te(NSN)₂TeX₂ in tetrahydrofuran. In the presence of MCl₃ (M = Ga, Al, Fe) besides (ClTeNSN)₃N�2THF also [MCl₂(THF)₄⁺][TeCl₅�THF^‐] could be isolated proving that TeCl₄ is an additional product in this decomposition process. The crystal structures for (ClTeNSN)₃N�2THF and [Cl₂Al(THF)₄⁺]‐[TeCl₅�THF^‐] are determined. The reaction steps for this complicated unforeseen decomposition, based on known reactions and substances, are discussed. Strong Lewis‐acids such as AlF₃ or AsF₅ form with F₂Te(NSN)₂TeF₂ mono‐ and tetrafold positively charged cations respectively. Metathetical reactions between F₂Te(NSN)_2‐TeF₂ and (CH₃)₃SiR provide R(F)Te(NSN)₂Te(F)R [R = CF₃C(O)O‐ and CF₃SO₂O‐]. When R₂Te(NSO)₂ is treated with TeF₄ the already mentioned compounds and F₃TeR are formed. The reaction of TeCl₄ with R₂Te(NSO)₂ gives Cl₃TeR and unsubstituted Cl₆Te₂N₂S ( 1 ). The condensation of TeX₄ with [(CH₃)₃SiNSN]₂S provides the corresponding tellurium containing eight membered rings X₂Te(NSN)₂S (X = F, Cl).     

New PF3 and Carbonyl Chemistry of Tantalum

Reduction of [TaCl₅] by six equivalents of alkali metal naphthalenide in 1,2-dimethoxyethane at −60°C followed by treatment with gaseous PF₃ provides the first homoleptic phosphane complex containing tantalum in the −1 oxidation state, [Ta(PF₃)₆]⁻. This can be protonated by concentrated sulfuric acid to yield the previously unknown highly acidic and volatile hydride [HTa(PF₃)₆]. An improved normal-pressure synthesis of [Ta(CO)₆]⁻ is described. Reduction of the latter species by sodium in liquid ammonia gives the carbonyl trianion [Ta(CO)₅]³⁻ which undergoes monoprotonation and stannylation to form [HTa(CO)₅]²⁻ and [Ph₃SnTa(CO)₅]²⁻, respectively. The hydride is a useful precursor to [(Ph₃PAu)₃Ta(CO)₅], the only known gold cluster of tantalum.     

Hypervalence in germanium compounds containing the tetracylic moiety {S(C6H3S)2O}Ge via O···Ge transannular interactions: A structural study

Treatment of R_nGeCl_4−n with {S(C₆H₃SH)₂O} (1) afforded the stable phenoxathiin-4,6-dithiolate compounds [{S(C₆H₃S)₂O}GeR₂] [n = 2; R = Et (2), Ph (3)] and [{S(C₆H₃S)₂O}GeRCl] [n = 1; R = Et (4), Ph (5)]. Treatment of GeCl₄ with 1 in benzene afforded the dichloro compound [{S(C₆H₃S)₂O}GeCl₂] (8) at 7 °C. Bromo compounds [{S(C₆H₃S)₂O}GeRBr] [R = Et (6), Ph (7)] and [{S(C₆H₃S)₂O}GeBr₂] (9) were synthesized by halogen exchange from the appropriate chloro derivative using KBr/HBr. X-ray structure determinations of diorganyl dithiolate compounds 2 and 3 revealed that germanium atom is contained in a boat–chair-shaped eight-membered central ring and displays a tetrahedral geometry. In contrast, compounds 4–6 display a boat–boat-shaped central ring with a significant intramolecular transannular O···Ge interaction. The geometry of the pentacoordinate Ge atom in these last complexes may be described as distorted trigonal bipyramidal with a 62–65% distortion displacement.     

Reactions of cyclochlorotriphosphazatriene with 2-mercaptoethanol. Calorimetric and spectroscopic investigations of the derived products

Abstract

The reactions of hexachlorocyclotriphosphazatriene, N₃P₃Cl₆ (1) with 2-mercaptoethanol, 2-HS-CH₂-CH₂-OH (2), in (1:1, 1:2 and 1:3) mole ratios, in excess of NaH, in THF and diethylether solutions yield a total of 6 novel products: one mono spiro, N₃P₃Cl₄[O-CH₂-CH₂-S] (3); one mono-substituted open chain, N₃P₃Cl₅[S-CH₂-CH₂-OH] (4); one dispiro, N₃P₃Cl₂[O-CH₂-CH₂-S]₂ (5); one tri-substituted open chain, N₃P₃Cl₃[S-CH₂-CH₂-OH]₃ (6); one tris-spiro, N₃P₃[O-CH₂-CH₂-S]₃ (7) and one disubstituted open chain, N₃P₃Cl₄[S-CH₂-CH₂-OH]₂ (8) derivatives. The spiro products (3, 5 and 7) are formed as the major products in this system and all of the synthesized compounds are found to be stable at room temperature. The structures of the derived compounds were elucidated by elemental analysis, TLC-MS, ³¹P and ¹H NMR spectral data. For evaluation of melting behavior of derivatives (6) and (7), thermal transition peaks and their corresponding enthalpies were determined via DSC technique.     

Preparation and Crystal Structures of Ternary Rare Earth Osmium Gallides LnOsGa3 (Ln = Gd—Tm) and LnOsGa3 (Ln = La—Nd)

The title compounds were prepared from the elemental components at high temperatures. The compounds LnOsGa₃ crystallize with the cubic TmRuGa₃ type structure which was refined from four‐circle X‐ray diffractometer data of TbOsGa₃: Pm3¯m, Z = 3, a = 640.8(1) pm, R = 0.014 for 173 structure factors and 10 variable parameters. The other gallides crystallize with a new structure type which was determined from single‐crystal X‐ray data of CeOsGa₄: Pmma, Z = 6, a = 963.9(2) pm, b = 880.1(1) pm, c = 767.0(1) pm, R = 0.030 for 744 F values and 56 variables. The structure may be considered as consisting of two kinds of alternating layers, although bonding within and between the layers is of similar strength. One kind of layers (A) is slightly puckered, two‐dimensionally infinite, hexagonal close packed, with the composition OsGa₃; the other kind of layers (B) is planar with the composition CeGa. The structure is closely related to that of Y₂Co₃Ga₉ where the corresponding layers have the compositions Co₃Ga₆ (A) and Y₂Ga₃ (B).     

A Convenient,Selective Synthesis of Bis[2,4‐bis(trifluoromethyl)phenyl]phosphane Derivatives Starting from 1,3‐Bis(trifluoromethyl)benzene

The reaction of the sterically shielded phosphane derivative, dichlorodiethylaminophosphane, Cl₂PNEt₂, with an excess of a mixture of 2,6‐bis(trifluoromethyl) and 2,4‐bis(trifluoromethyl)phenyl lithium gives bis[2,4‐bis(trifluoromethyl)phenyl]diethylaminophosphane, [2,4‐(CF₃)₂C₆H₃]₂PNEt₂, in 72 % yield as a colourless solid, while 2,6‐bis(trifluoromethyl)phenyl lithium remains unchanged in solution. The amino derivative crystallizes in the monoclinic space group P2₁/c (a 869.2(1), b 1857.4(1), c 1357.6(1) pm, β 100.57(4)°, Z = 4). Treatment of [2,4‐(CF₃)₂C₆H₃]₂PNEt₂ in CHCl₃ solution with conc. HCl allows the synthesis of [2,4‐(CF₃)₂C₆H₃)]₂PCl. [2,4‐(CF₃)₂C₆H₃]₂PCl reacts with H₂O in THF solution with quantitative formation of the corresponding secondary phosphane oxide. To obtain bis[2,4‐bis(trifluoromethyl)phenyl]phosphinic acid, [2,4‐(CF₃)₂C₆H₃]₂P(O)OH, quantitatively, a CHCl₃ solution of [2,4‐(CF₃)₂C₆H₃]₂P(O)H, has to be stirred in an NO₂ atmosphere. The phosphinic acid crystallizes is the triclinic space group (a 754.2(1), b 927.6(2), c 1305.5(2) pm, α 85.11(2)°, β 75.45(1)°, γ 79.99(2)°, Z = 2). From the reaction of the phosphinic acid with either elemental sodium or with cyanide salts, the corresponding phosphinate salts are obtained in an almost quantitatively yield.     

Reactions of Bromine Fluoride Dioxide,BrO2F,for the Generation of the Mixed‐Valent Bromine Oxygen Cations Br3O4+ and Br3O6+

A reliable synthesis of unstable and highly reactive BrO₂F is reported. This compound can be converted into BrO₂⁺SbF₆^?, BrO₂⁺AsF₆^?_, and BrO₂⁺AsF₆^??2 BrO₂F. The latter decomposes into mixed‐valent Br₃O₄?Br₂⁺AsF₆^? with five‐, three‐, one‐, and zero‐valent bromine. BrO₂⁺ H(SO₃CF₃)₂^? is formed with HSO₃CF₃. Excess BrO₂F yields mixed‐valent Br₃O₆⁺OSO₃CF₃^? with five‐ and three‐valent bromine. Reactions of BrO₂F and MoF₅ in SO₂ClF or CH₂ClF result in Cl₂BrO₆⁺Mo₃O₃F₁₃^?. The reaction of BrO₂F with (CF₃CO)₂O and NO₂ produces O₂Br‐O‐CO‐CF₃ and the known NO₂⁺Br(ONO₂)₂^?. All of these compounds are thermodynamically unstable.