Darstellung und elektrochemisches Verhalten von [Nb(OTeF5)6]− und [Ta(OTeF5)6]−-Komplexen

Preparation and Electrochemistry of [Nb(OTeF₅)₆]^? and [Ta(OTeF₅)₆]^? Complexes Nb(OTeF₅)₅ and Ta(OTeF₅)₅ react with Cs[OTeF₅], [Et₄N][OTeF₅], and [(n-Bu)₄N][OTeF₅] to the corresponding Cs[M(OTeF₅)₆], [Et₄N][M(OTeF₅)₆], and [(n-Bu)₄N][M(OTeF₅)₆] complexes, (M = Nb, Ta). The electrochemical reduction of the niobium complex occurs in CH₂Cl₂ at ?0,69 V and in acetonitrile at ?0,60 V (vs. SCE). The tantalum complex is reduced in CH₂Cl₂ at ?1,52 V and in acetonitrile at ?1,42 V (vs. SCE).     

Reactions of Chalcogen Oxide Chlorides EOCl2 (E = S,Se) with Group 5 Metal Chlorides

The tantalum derivative TaCl₅(SOCl₂), thermally unstable above 290 K, was prepared from Ta₂Cl₁₀ and SOCl₂ and studied by X‐ray crystallography at 180 K. Tantalum atom is octahedrally coordinated by five chlorides at Ta–Cl distances comprised between 2.32 and 2.36 Å and by the oxygen atom of SOCl₂ at the Ta–O distance of 2.34 Å. No evidence for the existence of an analogous compound of niobium(V) has been obtained. The halides of Group 5, M₂Cl₁₀, M = Nb, Ta, react with SeOCl₂ to give the solid adducts MCl₅(SeOCl₂) stable at room temperature. The reaction of NbCl₅(SeOCl₂) with SOCl₂ affords [SeCl₃][NbCl₆] which contains trigonal‐pyramidal (SeCl₃)⁺ cations with Se–Cl distances of 2.13–2.16 Å and octahedral [NbCl₆]^– anions (Nb–Cl: 2.27–2.45 Å). A distorted octahedral coordination around the selenium atom is achieved by additional interactions [Se…Cl, 2.81–2.98 Å] between selenium and the [NbCl₆]^– anion.     

Synthesis,Properties, and Application of Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4]−

Weakly coordinating anions (WCAs) are important for academic reasons as well as for technical applications. Tetrakis(pentafluoroethyl)gallate, [Ga(C₂F₅)₄]^?, a new WCA, is accessible by treatment of [GaCl₃(dmap)] (dmap=4‐dimethylaminopyridine) with LiC₂F₅. The anion [Ga(C₂F₅)₄]^? proved to be reluctant towards deterioration by aqueous hydrochloric acid or lithium hydroxide. Various salts of [Ga(C₂F₅)₄]^? were synthesized with cations such as [PPh₄]⁺, [CPh₃]⁺, [(O₂H₅)₂(OH₂)₂]²⁺, and [Li(dec)₂]⁺ (dec=diethyl carbonate). Thermolysis of [(O₂H₅)₂(OH₂)₂][Ga(C₂F₅)₄]₂ gives rise to a dihydrate of tris(pentafluoroethyl)gallane, [Ga(C₂F₅)₃(OH₂)₂]. All products were characterized by NMR and IR spectroscopy, mass spectrometry, X‐ray diffraction, and elemental analysis. Furthermore, an outlook for the application of [Li(dec)₂][Ga(C₂F₅)₄] as a conducting salt in lithium‐ion batteries is presented.     

Neue amido‐ und imidoverbrückte Kupferkomplexe – Synthesen und Strukturen von [{Li(OEt2)}2][Cu(NPh2)3], [ClCuN(SnMe3)3], [{CuN(SnMe3)2}4], [Cu16(NH2tBu)12Cl16], [{CuNHtBu}8], [Li(dme)3][Cu6(NHMes)3(NMes)2], [PPh3(C6H4)CuNHMes], [{[Li(dme)][Cu(NHMes)(NHPh)]}2] und [{Li(dme)3}3][Li(dme)2][Cu12(NPh)8]

New Amido and Imido Bridged Complexes of Copper – Syntheses and Structures of [{Li(OEt₂)}₂][Cu(NPh₂)₃], [ClCuN(SnMe₃)₃], [{CuN(SnMe₃)₂}₄], [Cu₁₆(NH₂^tBu)₁₂Cl₁₆], [{CuNH^tBu}₈], [Li(dme)₃][Cu₆(NHMes)₃(NMes)₂], [PPh₃(C₆H₄)CuNHMes], [{[Li(dme)][Cu(NHMes)(NHPh)]}₂], and [{Li(dme)₃}₃][Li(dme)₂][Cu₁₂(NPh)₈] The reactions of stannylated and lithiated amines with coppersalts (halogenides, thiocyanates) lead to amido and imido bridged complexes which contain one to twelve metal atoms. [{Li(OEt₂)}₂][Cu(NPh₂)₃] ( 1 ) results from the reaction of CuCl with LiNPh₂ in the presence of trimethylphosphine. With N(SnMe₃)₃, CuCl reacts to the donor‐acceptor complex [ClCuN(SnMe₃)₃] ( 2 ) that is transformed into the tetrameric complex [{CuN(SnMe₃)₂}₄] ( 3 ) by thermolysis. 3 can also be obtained by the reaction of LiN(SnMe₃)₂ with Cu(SCN)₂. While terminally bound in 1 , the amido ligand is μ₂‐bridging between copper atoms in compound 3 . The influence of the alkyl amide's leaving group can be seen from a comparison of the reactivity of Me₃SnNH^tBu and LiNH^tBu, respectively. With Me₃SnNH^tBu, CuCl₂ forms the polymeric compound [Cu₁₆(NH₂^tBu)₁₂Cl₁₆] ( 4 ) whereas in the case of LiNH^tBu with both CuCl and CuSCN, the complex [{CuNH^tBu}₈] ( 5 ) is obtained. The latter contains two planar Cu₄N₄‐rings similar to those in 3 . If a mesityl group is introduced at the lithium amide, different products are accessible. Both, CuBr and CuSCN, lead to the formation of [Li(dme)₃][Cu₆(NHMes)₃(NMes)₂] ( 6 ) whose anion consists of a prismatic copper core with μ₂‐bridging amido and μ₃‐bridging imido ligands. In the presence of PPh₄Cl, a mixture of Cu(SCN)₂ and LiNHMes enables an ortho‐metallation reaction that produces [PPh₃(C₆H₄)CuNHMes] ( 7 ). From the reaction of CuSCN with LiNHMes and LiNHPh either the dimeric complex [{[Li(dme)][Cu(NHMes)(NHPh)]}₂] ( 8 ) or the cluster [{Li(dme)₃}₃][Li(dme)₂][Cu₁₂(NPh)₈] ( 9 ) results. The anion in 9 exhibits a cubo‐octahedron of copper atoms μ₃‐bridged by (NPh)^2–‐ligands. The solid state structures of compounds 1 – 9 have been determined by single crystal X‐ray diffraction.     

Komplexe der Alkalimetalltetraphenylborate mit makrocyclischen Kronenethern

Complexes of the Alkali Metal Tetraphenylborates with Macrocyclic Crown Ethers Alkali metal tetraphenylborates, MB(C₆H₅)₄ (M = Li to Cs), react in tetrahydrofuran with macrocyclic crown ethers to give complexes of the general formula MB(C₆H₅)₄(crown)_m(THF)_n. Suitable single crystals for X‐ray structure analysis were grown from a solvent mixture of tetrahydrofuran and n‐hexane. The salt like complexes [Li(12‐crown‐4)(thf)][B(C₆H₅)₄] ( 1 ), [Na(15‐crown‐5)(thf)][B(C₆H₅)₄] ( 2 ), and [Cs(18‐crown‐6)₂][B(C₆H₅)₄] · THF ( 6 ), the mononuclear molecular complexes [KB(C₆H₅)₄(18‐crown‐6)(thf)] ( 3 ), [RbB(C₆H₅)₄(18‐crown‐6)] ( 4 ), and [CsB(C₆H₅)₄(18‐crown‐6)] · THF ( 5 ), and the compound [CsB(C₆H₅)₄(18‐crown‐6)]₂[Cs(18‐crown‐6)₂][B(C₆H₅)₄] ( 7 ), which contains a binuclear molecule ([CsB(C₆H₅)₄(18‐crown‐6)]₂) beside a [Cs(18‐crown‐6)₂]⁺ cation and a [B(C₆H₅)₄]^? anion, are described. All compounds are charactarized by infrared spectra, elemental analysis, NMR‐spectroscopy, and X‐ray single crystal structure analysis.     

Copper(II) and Cadmium(II) Complexes Based on N,N‐Bis(3, 5‐dimethyl‐2‐hydroxybenzyl)‐N‐(2‐pyridylmethyl)amine Ligand: Syntheses,Structures, Magnetic,and Luminescent Properties

The reaction of the aryl‐oxide ligand H₂L [H₂L = N,N‐bis(3, 5‐dimethyl‐2‐hydroxybenzyl)‐N‐(2‐pyridylmethyl)amine] with CuSO₄ · 5H₂O, CuCl₂ · 2H₂O, CuBr₂, CdCl₂ · 2.5H₂O, and Cd(OAc)₂ · 2H₂O, respectively, under hydrothermal conditions gave the complexes [Cu(H₂L¹)₂] · SO₄ · 3CH₃OH ( 1 ), [Cu₂(H₂L²)₂Cl₄] ( 2 ), [Cu₂(H₂L²)₂Br₄] ( 3 ), [Cd₂(HL)₂Cl₂] ( 4 ), and [Cd₂(L)₂(CH₃COOH)₂] · H₂L ( 5 ), where H₂L¹ [H₂L¹ = 2, 4‐dimethyl‐6‐((pyridin‐2‐ylmethylamino)methyl)phenol] and H₂L² [H₂L² = 2‐(2, 4‐dimethyl‐6‐((pyridin‐2‐ylmethylamino)methyl)phenoxy)‐4, 6‐dimethylphenol] were derived from the solvothermal in situ metal/ligand reactions. These complexes were characterized by IR spectroscopy, elementary analysis, and X‐ray diffraction. A low‐temperature magnetic susceptibility measurement for the solid sample of 2 revealed antiferromagnetic interactions between two central copper(II) atoms. The emission property studies for complexes 4 and 5 indicated strong luminescence emission.     

Kronenetherkomplexe von Blei(II). Die Kristallstrukturen von [PbCl(18-Krone-6)][SbCl6], [Pb(18-Krone-6)(CH3CN)3][SbCl6]2, and [Pb(15-Krone-5)2][SbCl6]2

Crown Ether Complexes of Lead(II). The Crystal Structures of [PbCl(18-Krone-6)][SbCl₆], [Pb(18-Krone-6)(CH₃CN)₃][SbCl₆]₂ und [Pb(15-Krone-5)₂][SbCl₆]₂ . [PbCl(18-crown-6)][SbCl₆] has been prepared in low yield besides [Pb(CH₃)₂(18-crown-6)][SbCl₆]₂ by the reaction of Pb(CH₃)₂Cl₂ with antimony pentachloride in acetonitrile solution in the presence of 18-crown-6, forming pale-yellow crystals. The other two title compounds are formed as colourless crystals by the reaction of PbCl₂ with antimony pentachloride in acetonitrile solutions in the presence of 18-crown-6 and 15-crown-5, respectively. The complexes were characterized by IR spectroscopy and by crystal structure determinations. [PbCl(18-crown-6)][SbCl₆]: Space group P2₁/c, Z = 8, 5 003 observed unique reflections, R = 0.046. Lattice dimensions at - 80°C: a = 1 386.9; b = 1 642.7; c = 2 172.1 pm, β = 92.95°. The lead atom in the cation [PbCl(18-crown-6)]⁺ is surrounded in an almost hexagonal-planar construction by the six oxygen atoms of the crown ether and an axially oriented Cl atom. [Pb(18-crown-6)(CH₃CN)₃][SbCl₆]₂: Space group P1 , Z = 2, 6 128 observed unique reflections, R = 0.076. Lattice dimensions at - 70°C: a = 1 228.0; b = 1 422.9; c = 1 463.2 pm, α = 69.08°; β = 65.71°; γ = 64.51°. In the cation [Pb(18-crown-6)(CH₃CN)₃]²⁺ the lead atom is coordinated by the six oxygen atoms of the crown ether and by the three nitrogen atoms of the acetonitrile molecules. The structure determination is restricted by disorder. [Pb( 15-crown-5)₂][SbCI₆]₂: Space group P6₃/m, Z = 6, 5 857 observed unique reflections, R = 0.059. Lattice dimensions at -70°C: a = b = 2 198.5; c = 1499.4 pm, α = β = 90°, γ = 120°. In the cation [Pb(l5-crown-5)₂]² the lead atom is sandwich-like coordinated by the ten oxygen atoms of the two crown ether molecules. The structure determination is restricted by disorder.     

The first compound with an unusual type of anion, [Li(SR)2]–: bis­(μ2‐aqua‐d2)tetra­kis(aqua‐d2)dilithium(I) bis­[bis­(tri‐tert‐butoxy­silanethiol­ato‐κ2O,S)lithate(I)] dihydrate‐d2

The title complex, [Li₂(D₂O)₆][Li(C₉H₂₇SSiO₃)₂]₂·2D₂O, is the first compound with an S—M bond (M = alkali metal) within an unusual type of lithate anion, [Li(SR)₂]⁻ {where R is Si[OC(CH₃)₃]₃}. There is a centre of symmetry located in the middle of the Li₂O₂ ring of the cation. All Li atoms are four‐coordinate, with LiO₄ (cations) and LiO₂S₂ (anions) cores. The singly charged [Li(SR)₂]⁻ anions are well separated from the doubly charged [Li₂(D₂O)₆]²⁺ cations; the distance between Li atoms from differently charged ions is greater than 5 Å. Both ion types are held within an extended network of O—D⋯O and O—D⋯S hydrogen bonds.     

Strukturen zweifach metallierter Derivate von 3, 3‐Dimethyl‐1, 5‐bis(trimethylsilyl)‐1, 5‐diaza‐pentan mit Lithium und Aluminium sowie zweier Donor‐substituierter Digallane

Structural Characterization of Bis(metallated) Derivatives of 3, 3‐Dimethyl‐1, 5‐bis(trimethylsilyl)‐1, 5‐diaza‐pentane with Lithium and Aluminum and of two Donor‐substituted Digallanes The diaminopropane derivative Me₂C[CH₂N(H)SiMe₃]₂ is metallated with n‐butyllithium and lithium tetrahydridoaluminate to obtain Me₂C[CH₂N(Li)SiMe₃]₂ and Me₂C[CH₂N(Li)SiMe₃][CH₂N(AlH₂)SiMe₃], respectively. Both compounds exhibit a central eight‐membered ring, Li₄N₄ or Li₂Al₂N₄. Me₂C[CH₂N(Li)SiMe₃]₂ reacts with Ga₂Cl₄ · 2dioxane under formation of the corresponding tetra(amino)digallane. This is monomeric, in contrast to a dimeric tetraalkoxy‐substituted digallane, Ga₄O^tBu₈. All compounds were characterized by single crystal X‐ray crystallography.     

Long‐Lived Radical Cation Salts Obtained by Interaction of Monocyclic Arenes with Niobium and Tantalum Pentahalides at Room Temperature: EPR and DFT Studies

The 1:3 reactions of the alkoxy arenes 1,4‐(MeO)₂C₆H₄ and 1,4‐F₂‐2,5‐(MeO)₂C₆H₂ with TaF₅ in chloroform at 40–50 °C resulted in formation in about 35 % yield of the long‐lived radical cation salts [1,4‐(MeO)₂C₆H₄][Ta₂F₁₁] ( 2 a ) and [1,4‐F₂‐2,5‐(MeO)₂C₆H₂][Ta₂F₁₁] ( 2 b ), respectively. The non‐alkoxy‐substituted [arene][M₂X₁₁] [M=Ta, X=F: arene=C₆H₅Me ( 2 c ), 1,4‐C₆H₄Me₂ ( 2 d ), C₆H₅F ( 2 e ), C₆H₅NO₂ ( 2 f ); M=Nb, X=F: arene=C₆H₅Me ( 4 a ), 1,4‐C₆H₄Me₂ ( 4 b ), C₆H₅F ( 4 c ), C₆H₅NO₂ ( 4 d ); M=Ta, X=Cl: arene=1,4‐C₆H₄Me₂ ( 5 )] were obtained from the 3:1 reactions of MX₅ with the appropriate arene in chloroform at temperatures in the range 40–90 °C. Compounds 2 – 5 were detected by EPR spectroscopy (in CHCl₃) at room temperature, and their gas‐phase structures were optimized by DFT calculations. Formation of the M^IV species [MX₄(NCMe)₂] [M=Ta, X=F ( 3 a ); M=Nb, X=F ( 3 b ); M=Ta, X=Cl ( 3 c )] was ascertained by EPR spectroscopy on solutions obtained by treatment of the reaction mixtures with acetonitrile. Non‐selective reactions occurred upon combination of 1,4‐F₂‐2,5‐(MeO)₂C₆H₂ with AgNbF₆ (in CH₂Cl₂) and 1,4‐(MeO)₂C₆H₄ with SbF₅.     

Zum Koordinationsverhalten der Phenylhydrazonpropandinitrile: Darstellung und strukturelle Charakterisierung von Silber(I)‐Komplexen

On the Coordination Behaviour of Phenylhydrazonepropanedinitriles: Preparation and Structural Characterization of Silver(I) Complexes The preparation of novel silver(I) complexes with anions of phenylhydrazonepropanedinitriles [XC₆H₄NNC(CN)₂]^— (X = H or NO₂) is described. The structures of the following complex compounds are determined by X‐ray diffraction on single crystals: [Ag{O₂NC₆H₄NNC(CN)₂}] ( 2 ), [Ag{C₆H₅NNC(CN)₂}(PPh₃)] · CH₂Cl₂ ( 3 · CH₂Cl₂), [Ag{C₆H₅NNC(CN)₂}(PPh₃)₂] · 0, 5 CH₂Cl₂ ( 4 · 0, 5 CH₂Cl₂) and [Ag(PPh₃)₄][C₆H₅NNC(CN)₂] ( 5 ). In these complexes a variety of coordination modes of the phenylhydrazonepropanedinitrile anions are observed. In 3 and 4 the phenylhydrazonide anion is coordinated via the hydrazone nitrogen atom N(2). 2 shows the structure of a coordination polymer, where the phenylhydrazone coordinates as a tridentate ligand through both nitrile nitrogen atoms and the hydrazone nitrogen atom N(2). In 5 appears a free, non coordinated phenylhydrazonide anion.     

The Cocrystallization of the Cubic [Ta6Br12(H2O)6][CuBr2X2]·10H2O and Triclinic [Ta6Br12(H2O)6]X2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O (X = Cl,Br, NO3) Phases with the Coexistence of [Ta6Br12]2+ and [Ta6Br12]4+ in the Latter

Cubic [Ta₆Br₁₂(H₂O)₆][CuBr₂X₂]·10H₂O and triclinic [Ta₆Br₁₂(H₂O)₆]X₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O (X = Cl, Br, NO₃) cocrystallize in aqueous solutions of [Ta₆Br₁₂]²⁺ in the presence of Cu²⁺ ions. The crystal structures of [Ta₆Br₁₂(H₂O)₆]Cl₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O ( 1 ) and [Ta₆Br₁₂(H₂O)₆]Br₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O ( 3 )have been solved in the triclinic space group P&1macr; (No. 2). Crystal data: 1 , a = 9.3264(2) Å, b = 9.8272(2) Å, c = 19.0158(4) Å, α = 80.931(1)?, β = 81.772(2)?, γ = 80.691(1)?; 3 , a = 9.3399(2) Å, b = 9.8796(2) Å, c = 19.0494(4) Å; α = 81.037(1)?, β = 81.808(1)?, γ = 80.736(1)?. 1 and 3 consist of two octahedral differently charged cluster entities, [Ta₆Br₁₂]²⁺ in the [Ta₆Br₁₂(H₂O)₆]²⁺ cation and [Ta₆Br₁₂]⁴⁺ in trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]. Average bond distances in the [Ta₆Br₁₂(H₂O)₆]²⁺ cations: 1 , Ta‐Ta, 2.9243 Å; Ta‐Brⁱ , 2.607 Å; Ta‐O, 2.23 Å; 3 , Ta‐Ta, 2.9162 Å; Ta‐Brⁱ , 2.603 Å; Ta‐O, 2.24 Å. Average bond distances in trans‐[Ta₆‐Br₁₂(OH)₄(H₂O)₂]: 1 , Ta‐Ta, 3.0133 Å; Ta‐Brⁱ, 2.586 Å; Ta‐O(OH), 2.14 Å; Ta‐O(H₂O), 2.258(9) Å; 3 , Ta‐Ta, 3.0113 Å; Ta‐Brⁱ, 2.580 Å; Ta‐O(OH), 2.11 Å; Ta‐O(H₂O), 2.23(1) Å. The crystal packing results in short O···O contacts along the c axes. Under the same experimental conditions, [Ta₆Cl₁₂]²⁺ oxidized to [Ta₆Cl₁₂]⁴⁺ , whereas [Nb₆X₁₂]²⁺ clusters were not affected by the Cu²⁺ ion.     

Die Reaktionen von M[BF4] (M = Li,K) und (C2H5)2O·BF3 mit (CH3)3SiCN. Bildung von M[BFx>(CN)4—x] (M = Li,K; x = 1, 2) und (CH3)3SiNCBFx(CN)3—x, (x = 0, 1)

The Reactions of M[BF₄] (M = Li, K) and (C₂H₅)₂O·BF₃ with (CH₃)₃SiCN. Formation of M[BF_x(CN)_4—x] (M = Li, K; x = 1, 2) and (CH₃)₃SiNCBF_x(CN)_3—x, (x = 0, 1) The reaction of M[BF₄] (M = Li, K) with (CH₃)₃SiCN leads selectively, depending on the reaction time and temperature, to the mixed cyanofluoroborates M[BF_x(CN)_4—x] (x = 1, 2; M = Li, K). By using (C₂H₅)₂O·BF₃ the synthesis yields the compounds (CH₃)₃SiNCBF_x(CN)_3—x x = 0, 1. The products are characterized by vibrational and NMR‐spectroscopy, as well as by X‐ray diffraction of single‐crystals: Li[BF₂(CN)₂]·2Me₃SiCN Cmc2₁, a = 24.0851(5), b = 12.8829(3), c = 18.9139(5) Å V = 5868.7(2) ų, Z = 12, R₁ = 4.7%; K[BF₂(CN)₂] P4₁2₁2, a = 13.1596(3), c = 38.4183(8) Å, V = 6653.1(3) ų, Z = 48, R₁ = 2.5%; K[BF(CN)₃] P1¯, a = 6.519(1), b = 7.319(1), c = 7.633(2) Å, α = 68.02(3), β = 74.70(3), γ = 89.09(3)°, V = 324.3(1) ų, Z = 2, R₁ = 3.6%; Me₃SiNCBF(CN)₂ Pbca, a = 9.1838(6), b = 13.3094(8), c = 16.840(1) Å, V = 2058.4(2) ų, Z = 8, R₁ = 4.4%     

Die Oxochlorotantalate (PPh4)2[Ta2OCl9]2 · 2 CH2Cl2, (PPh4)2[Ta2OCl10] · 2 CH3CN und (K-18-Krone-6)4[Ta4O6Cl12] · 12 CH2Cl2

The Oxochlorotantalates (PPh₄)₂[Ta₂OCl₉]₂ · 2 CH₂Cl₂, (PPh₄)₂[Ta₂OCl₁₀] · 2 CH₃CN, and (K-18-crown-6)₄[Ta₄O₆Cl₁₂] · 12 CH₂Cl₂ (K-18-crown-6)₄[Ta₄O₆Cl₁₂] · 12 CH₂Cl₂ was obtained from a reaction of tantalum pentachloride, K₂S₅ and 18-crwon-6 in dichlormethane. According to its crystal structure analysis it is tetragonal (space group I 4 2d) and contains [Ta₄O₆Cl₁₂]^4– ions that have an adamantane-like Ta₄O₆ skeleton. Each K⁺ ion is coordinated by the oxygen atoms of the crown ether molecule from one side and with three Cl atoms of one [Ta₄O₆Cl₁₂]^4– ion from the opposite side. (PPh₄)₂[Ta₂OCl₁₀] · 2 CH₃CN was a product from PPh₄Cl and TaCl₅ in acetonitrile in the presence of Na₂S₄. Its crystals are monoclinic (space group P2₁/c) and contain centrosymmetric [Ta₂OCl₁₀]^2– ions having a linear Ta–O–Ta grouping with short bonds (Ta–O 189 pm). TaCl₅ and H₂S formed a solid substance (TaSCl₃) from which a small amount of (PPh₄)₂[Ta₂OCl₉]₂ · 2 CH₂Cl₂ was obtained by the reaction with PPh₄Cl in CH₂Cl₂. The anions in the monoclinic crystals (space group P2₁/n) consist of two Ta₂OCl₉^– units which are joined by chloro bridges; each Ta₂OCl₉^– unit has a nearly linear Ta–O–Ta group with differing bond lengths (179 and 202 pm). The oxygen in the compounds probably was introduced by traces of water in the crown ether, acetonitrile or H₂S, respectively.     

Triamidoamine–Uranium(IV)‐Stabilized Terminal Parent Phosphide and Phosphinidene Complexes

Reaction of [U(Tren^TIPS)(THF)][BPh₄] ( 1 ; Tren^TIPS=N{CH₂CH₂NSi(iPr)₃}₃) with NaPH₂ afforded the novel f‐block terminal parent phosphide complex [U(Tren^TIPS)(PH₂)] ( 2 ; U–P=2.883(2) Å). Treatment of 2 with one equivalent of KCH₂C₆H₅ and two equivalents of benzo‐15‐crown‐5 ether (B15C5) afforded the unprecedented metal‐stabilized terminal parent phosphinidene complex [U(Tren^TIPS)(PH)][K(B15C5)₂] ( 4 ; U?P=2.613(2) Å). DFT calculations reveal a polarized‐covalent U?P bond with a Mayer bond order of 1.92.     

Titanium(IV) Cations with Trigonal Monopyramidal Geometry: Unusual Lewis Acids Supported by a Triaryl Triamidoamine Ligand

Protonolysis of the titanium alkyl complex [Ti(CH₂SiMe₃)(Xy-N₃N)] (Xy-N₃N=[{(3,5-Me₂C₆H₃)NCH₂CH₂}₃N]³⁻) supported by a triamidoamine ligand, with [NEt₃H][B(3,5-Cl₂C₆H₃)₄] or [PhNMe₂H][B(C₆F₅)₄] afforded the cations [Ti(Xy-N₃N)][A] (A⁻=[B(3,5-Cl₂C₆H₃)₄]⁻ ( 1[B(Ar^Cl)₄] ; B(Ar^Cl)₄=tetrakis(3,5-dichlorophenyl)borate); A⁻=[B(C₆F₅)₄]⁻ ( 1[B(Ar^F)₄] ; B(Ar^F)₄=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate). These Lewis acidic cations were reacted with coordinating solvents to afford the cations [Ti(L)(Xy-N₃N)][B(C₆F₅)₄] ( 2-L ; L=Et₂O, pyridine and THF). XRD analysis revealed a trigonal monopyramidal (TMP) geometry for the tetracoordinate cations in 1[B(Ar^X)₄] and trigonal bipyramidal (TBP) geometry for the pentacoordinate cations in 2-L . Variable-temperature NMR spectroscopy showed a dynamic equilibrium for 2-Et₂O in solution, involving the dissociation of Et₂O. Coordination to the titanium(IV) center activated the THF molecule, which, in the presence of NEt₃, underwent ring-opening to give the titanium alkoxide [Ti(O(CH₂)₄NEt₃)(Xy-N₃N)][B(3,5-Cl₂C₆H₃)₄] ( 3 ). Hydride abstraction from C_β,eq of the triamidoamine ligand arm in [Ti(CH₂SiMe₃)(Xy-N₃N)] or [Ti(NMe₂)(Xy-N₃N)] with [Ph₃C][B(3,5-Cl₂C₆H₃)₄] led to the diamidoamine–imine complex [Ti(R){(Xy-N=CHCH₂)(Xy-NCH₂CH₂)₂N}][B(3,5-Cl₂C₆H₃)₄] (R=CH₂SiMe₃ ( 4 a ); R=NMe₂ ( 4 b )). Hydride addition to 4 b with [Li(THF)][HBPh₃] gave [Ti(NMe₂)(Xy-N₃N)], whereas KH deprotonated further to give [Ti(NMe₂){(Xy-NCH=CH)(Xy-NCH₂CH₂)₂N}] ( 5 ). XRD on single crystals of 3 and 4 b confirmed the proposed structures.     

Bis­[bis­(di­phenyl­phosphino­methyl)­phenyl­phosphine]­di­chloro­tetra­gold(I) bis­[chloro­tris­(penta­fluoro­phenyl)­aurate(III)]

The cation of the title compound, [Au₄(PPh₂CH₂PPhCH₂PPh₂)₂Cl₂][Au(C₆F₅)₃Cl]₂ or [Au₄Cl₂(C₃₂H₂₉P₃)₂][AuCl(C₆F₅)₃]₂, displays a rhomboidal geometry for the Au atoms, with short Au?Au distances of 3.104 (2) and 3.185 (1) Å; the linear coordination at the Au^I atoms is distorted: P—Au—P 164.7 (2)° and P—Au—Cl 170.67 (11)°. The anion shows the expected square‐planar geometry at Au^III, with the Au atom 0.022 (5) Å out of the plane of the four donor atoms.     

Oxygen-Bridged Ga2(Et)3(OTeF5)3 and the Weakly Coordinating Anions [Ga(Et)(OTeF5)3]− and [Ga(OTeF5)4]−

Salts of the weakly coordinating anions [Ga(OTeF₅)₄]⁻ as well as [Ga(Et)(OTeF₅)₃]⁻ and the neutral Ga₂(Et)₃(OTeF₅)₃ were synthesized and characterized by spectroscopic methods and single-crystal X-ray diffraction. Ga₂(Et)₃(OTeF₅)₃ was formed by treating GaEt₃ with pentafluoroorthotelluric acid (HOTeF₅) and reacted with PPh₄Cl and CPh₃Cl to [PPh₄][Ga(Et)(OTeF₅)₃] and [CPh₃][Ga(Et)(OTeF₅)₃]. In contrast, Ag[Ga(OTeF₅)₄] was prepared from AgOTeF₅ and GaCl₃ and was used as a versatile starting material for further reactions. Starting with Ag[Ga(OTeF₅)₄] the substrates [PPh₄][Ga(OTeF₅)₄] and [CPh₃][Ga(OTeF₅)₄] were formed from PPh₄Cl and CPh₃Cl.     

Neue Kupfer(I,II)-Verbindungen

New Copper(I, II) Compounds Complexes of the type [Cu^II(N∩N)₂][Cu^ICl_1+x]_2x (N∩N = en, pn, 2-amino picoline) are prepared from Cu(N∩N)₂Cl₂ and copper(I) chloride. [Cu^II(enac)][Cu^ICl₂]₂ — a complex with a macrocyclic cation — is obtained, by the reaction of Cuen₂Cl₂ in aqueous acetone. Diacetyl monoxime partially reduces copper(II) of Cu(NSMe)₂Cl₂ and in this way causes the formation of [Cu(NSMe)_2][CuCl₃] (NSMe = β-aminoethyl methylsulfide). On the other hand a template reaction of this oxime with Cu(NSMe)₂ (ClO₄)₂ produces Cu^II(ONNSMe)(ClO₄) (HONNSMe?CH₃C(NOH)C(NCH₂CH₂SCH₃)CH₃), which shows a reduced paramagnetism. Basing on magnetic behaviour, i. r. and vis spectra the structure of the new compounds is discussed.     

The Arene‐Stabilized η5‐Pentamethylcyclopentadienyl Arsenic Dication [(η5‐Cp*)As(toluene)]2+

Double chloride abstraction of Cp*AsCl₂ gives the dicationic arsenic species [(η⁵‐Cp*)As(tol)][B(C₆F₅)₄]₂ ( 2 ) (tol=toluene). This species is shown to exhibit Lewis super acidity by the Gutmann–Beckett test and by fluoride abstraction from [NBu₄][SbF₆]. Species 2 participates in the FLP activation of THF affording [(η²‐Cp*)AsO(CH₂)₄(THF)][B(C₆F₅)₄]₂ ( 5 ). The reaction of 2 with PMe₃ or dppe generates [(Me₃P)₂As][B(C₆F₅)₄] ( 6 ) and [(σ‐Cp*)PMe₃][B(C₆F₅)₄] ( 7 ), or [(dppe)As][B(C₆F₅)₄] ( 8 ) and [(dppe)(σ‐Cp*)₂][B(C₆F₅)₄]₂ ( 9 ), respectively, through a facile cleavage of C?As bonds, thus showcasing unusual reactivity of this unique As‐containing compound.