Synthese und Kristallstrukturen von [Li(thf)4]2[Bi4I14(thf)2], [Li(thf)4]4[Bi5I19] und (Ph4P)4[Bi6I22]

Synthesis and Crystal Structure of [Li(thf)₄]₂[Bi₄I₁₄(thf)₂], [Li(thf)₄]₄[Bi₅I₁₉], and (Ph₄P)₄[Bi₆I₂₂] Solutions of BiI₃ in THF or methanol react with MI (M = Li, Na) to form polynuclear iodo complexes of bismuth. The syntheses and results of X-ray structure analyses of compounds [Li(thf)₄]₂[Bi₄I₁₄(thf)₂], [Li(thf)₄]₄[Bi₅I₁₉], [Na(thf)₆]₄[Bi₆I₂₂] and (Ph₄P)₄[Bi₆I₂₂] are described. The anions of these compounds consist of edge-sharing BiI₆ and BiI₅(thf) octahedra. The Bi atoms lie in a plane and are coordinated by bridging and terminal I atoms and by THF ligands in a distorted octahedral fashion. [Li(thf)₄]₂[Bi₄I₁₄(thf)₂]: Space group P1 (No. 2), a = 1 159.9(6), b = 1 364.6(7), c = 1 426.5(7) pm, α = 114.05(3), β = 90.01(3), γ = 100.62(3)°. [Li(thf)₄]₄[Bi₅I₁₉]: Space group P2₁/n (No. 14), a = 1 653.0(9), b = 4 350(4), c = 1 836.3(13) pm, β = 114.70(4)°. [Na(thf)₆]₄[Bi₆I₂₂]: Space group P2₁/n (No. 14), a = 1 636.4(3), b = 2 926.7(7), c = 1 845.8(4) pm, β = 111.42(2)°. (Ph₄P)₄[Bi₆I₂₂]: Space group P1 (No. 2), a = 1 368.6(7), b = 1 508.1(9), c = 1 684.9(8) pm, α = 98.28(4), β = 95.13(4), γ = 109.48(4)°.     

The first observation of the [Cp3Mn]- anion; structures of hexagonal [(eta 2-Cp)3MnK.1.5thf] and ion-separated [(eta 2-Cp)3Mn]2[Mg(thf)6].2thf

Hexagonal [(eta 2-Cp)3MnK.1.5thf] 1 and ion-separated [(eta 2-Cp)3Mn]2[Mg(thf)6].2thf 2 are obtained from reactions of CpK and Cp2Mg, respectively, with manganocene, Cp2Mn; they are the first complexes to be structurally characterised containing the [Cp3Mn]- anion.     

Syntheses and Molecular Structures of [(thf)4Li] [{(thf)Li}M(C4H8)3] (M = Zr,Hf) and Their Solution Behavior

The reaction of MCl₄(thf)₂ (M = Zr, Hf) with 1,4-dilitiobutane in diethyl ether at –25 °C or at 0 °C with a molar ratio of 1 : 3 yields the homoleptic “ate” complexes [(thf)₄Li] [{(thf)Li}M(C₄H₈)₃] 1 - Zr (M = Zr) and 1 - Hf (M = Hf). The crystalline compounds form ion lattices with solvent-separated [(thf)₄Li]⁺ cations and [{(thf)Li}M(C₄H₈)₃]^– anions. The NMR spectra at –20 °C show magnetic equivalence of the M–CH₂ and of the β-CH₂ groups of the butane-1,4-diide ligands on the NMR time scale. Analogous reactions of MCl₄(thf)₂ with 1,4-dilithiobutane with a molar ratio of 1 : 2 proceed unclear. However, single crystals of [Li(thf)₄] [HfCl₅(thf)] ( 2 ) can be isolated with the hafnium atom in a distorted octahedral coordination sphere of five chloro and one thf ligand. NMR spectra allow to elucidate the time-dependent degradation of 1-Hf and 1-Zr in THF and toluene at 25 °C via THF cleavage. Addition of tmeda to a solution of 1-Zr allows the isolation of intermediately formed [{(tmeda)Li}₂Zr(nBu)₂(C₄H₈)₂] ( 3 ).     

Synthese und Struktur eines Molybdän–Gadolinium-Heterometall-Komplexes Die Struktur von [Li(thf)4]2[Cp2MoSGdBr4(thf)]2

Synthesis and structure of a Molybdenum–Gadolinium Heterometallic Complex. The Structure of [Li(thf)₄]₂[Cp₂MoSGdBr₄(thf)]₂ [Cp₂MoHLi] reacts in THF with S and GdBr₃ to yield the tetranuclear heterobimetallic complex [Li(thf)₄]₂[Cp₂MoSGdBr₄(thf)]₂. The bonding situation and the structure of this compound were characterized by X-ray structure analysis (space group P1 (No. 2), Z = 1, a = 10.845(2) Å, b = 12.166(2) Å, c = 15.881(2) Å, α = 101.74(2)°, β = 97.62(2)°, γ = 103.97(2)°). Each S atom of the central Mo₂S₂-ring is coordinated by a GdBr₄(thf) fragment. Additionally each Mo atom is connected to two Cp ligands. This leads to a tetrahedral coordination of the Mo atoms and a octahedral coordination of the Gd ions.     

Synthesis and structural analysis of the polymetallated alkali calixarenes [M4(p-tert-butylcalix[4]arene-4H)(thf)x]2.n THF (M=Li,K; n=6 or 1; x=4 or 5) and [Li2(p-tert-butylcalix[4]arene-2H)(H2O)(mu-H2O)(thf)].3 THF

To study the structures and reactivities of alkali metallated intermediates of calix[4]arenes, three compounds were isolated: [Li(4)(p-tert-butylcalix[4]arene-4H)(thf)(4)](2).6 THF (1), [Li(2)(p-tert-butylcalix[4]arene-2H)(H(2)O)(mu-H(2)O)(thf)].3 THF (2), and [K(4)(p-tert-butylcalix[4]arene-4H)(thf)(5)](2).THF (3). The structure of 1 is shown to be dependent on the coordinating solvent. Partial hydrolysis of 1 leads to the formation of 2. The potassium compound 3 features a different structure to that of 1, due to a higher coordination number as well as stronger cation-pi-bonding interactions.     

Encapsulation of Chloride-water cluster anion [Cl6(H2O)8]6- in a cage structure based [Cu(DMAP)4]2+ aggregation

A well chloride?water cluster [Cl₆(H₂O)₈]^6? in the complex [Cu₃(DMAP)₁₂Cl₆?8H₂O] (DMAP = N,N’-dimethyl p-aminopyridine) has been investigated structurally in the solid state. The chloride-water cluster [Cl₆(H₂O)₈]^6? is stabilized and orderly arranged by hydrogen bonds which display high symmetry. Six hosts [Cu(DMAP)₄]²⁺ cationic form a cage-like aggregation, and chloride-water [Cl₆(H₂O)₈]^6? cluster located in the cage. Cl^? anion play an important role to connect cubane-like (H₂O)₈ water cluster forming [Cl₆(H₂O)₈]^6? cluster, and on the other hand, to connect cage-like [Cu(DMAP)₄]²⁺ cationic aggregation by means of ionic electrostatic interaction and long-range coordinate bond interaction. The formation of such a cluster anion may be available for insight into the nature of hydration of chloride in H₂O.     

The unexpected formation of a lithium-enolate from bis2-[(dimethylamino)methyl]phenyl copper lithium. X-ray structure of Li4[OC(CH2)C6H4CH2NMe2-2]4

Attempted crystallization of the bis(aryl)lithium cuprate, Cu₂Li₂(C₆H₄CH₂-NMe₂-2)₄, from diethyl ether/pentane afforded in according to an X-ray diffraction analysis appeared to be the lithium enolate, Li₄[OC(=CH₂)C₆H₄CH₂NMe₂-2]₄. This consists of a central Li₄O₄ cube with intramolecular LiN coordination of the CH₂NMe₂ substituent. This enolate, which has also been prepared via an independent route, is the first example of a structurally characterized lithium enolate and contains Li centres that are intramolecularly coordinated.     

Zur Reaktion von Makrozyklen mit Lanthanoiden. II. Die Strukturen von [K(thf)3]2[(C22H28N4)2Sm2] · 4THF und [(C22H22N4)Co] · DME

On the Reaction of Macrocycles with Lanthanoids. II. The Crystal Structures of [K(thf)₃]₂[(C₂₂H₂₈N₄)₂Sm₂] · 4 THF and [(C₂₂H₂₂N₄)Co] · DME In a complicated redox reaction [(TMTAA)K₂] and [SmI₂(thf)₂] form the polynuclear metal complex [K(thf)₃]₂[(TMTAT)₂Sm₂]. This complex crystallizes with four molecules THF per formula unit and its structure was determined by single crystal X-ray investigation (spacegroup P2₁/c (No. 14), z = 4, a = 998.0(2) pm, = b = 2618.3(6) pm, c = 1619.4(3) pm, β = 96.52(2)°). In the dimeric unit [(TMTAT)₂Sm₂]^2? the Sm³⁺ ions are bonded to the four N atoms of the macrocyclic ligand and one C₆H₄ ring of the second ligand is attached η⁶ like to one metal ion. Additionally two [K(thf)₃]⁺ fragments are bonded to this central unit, and therefor coordination number seven results for the K⁺ ion. [TMTAA]^2? is not reduced by [Cp₂Co] in a similar reaction. The monomeric paramagnetic complex [(TMTAA)Co] (μ_eff = 2,76 μ_B) is formed instead. The structure reveils a square planar coordination of the Co atom by the four N atoms of the TMTAA ligand (spacegroup C2/c (No. 15), z = 4, a = 1945.1(4) pm, b = 1165.6(2) pm, c = 1144.7(2) pm, β = 116.38(1)°).     

Ligand exchange reaction between an alkylzinc primary amide and a dialkylmagnesium compound: crystal structures of [(thf)MeMg-mu-N(H)SiiPr3]2 and (tmeda)Mg[N(H)SiiPr3]2

The reaction of alkylzinc triisopropylsilylamide with dialkylmagnesium leads to a ligand exchange. Besides the starting materials, heteroleptic alkylmagnesium triisopropylsilylamide and homoleptic magnesium bis(triisopropylsilylamide) are detected by NMR spectroscopy. After the addition of 1,2-bis(dimethylamino)ethane (TMEDA) to the reaction mixture, (tmeda)Mg[N(H)SiiPr3]2 (1) precipitates as colorless cuboids (C24H60MgN4Si2, a = 2269.6(2), b = 1029.58(5), c = 1593.2(1) pm, beta = 120.826(8) degrees , monoclinic, C2/c, Z = 4). The amide nitrogen atoms are coordinated planarily with strongly widened Mg-N-Si bond angles of 139.2(1) degrees . The metalation of triisopropylsilylamine with dimethylmagnesium in THF yields quantitatively heteroleptic [(thf)MeMg-N(H)SiiPr3]2 (2) which crystallizes as colorless needles (C28H66Mg2N2O2Si2, a = 1982.4(2), b = 2034.1(1), c = 907.22(6) pm, beta = 95.021(9), monoclinic, P2(1)/n, Z = 4). Because of the bridging position of the triisopropylsilylamide anion, the tetracoordinate nitrogen atoms show rather long Mg-N bond lengths of 210.7 pm (average value).     

Synthesis and structures of the [benzamidinato]3- complexes Li3(tmeda)(L1)]2 and [Li(thf)4][Li5(L2)(OEt2)2] [L1 = N(SiMe3)C(Ph)N(SiMe3) and L2 = N(SiMe3)C(C6H4-4)NPh

Reduction at ambient temperature of each of the lithium benzamidinates [Li(L(1))(tmeda)] or [{Li(L(2))(OEt(2))(2)}(2)] with four equivalents of lithium metal in diethyl ether or thf furnished the brown crystalline [Li(3)(L(1))(tmeda)] (1) or [Li(thf)(4)][Li(5)(L(2))(2)(OEt(2))(2)] (2), respectively. Their structures show that in each the [N(R(1))C(R(3))NR(2)](3-) moiety has the three negative charges largely localised on each of N, N' and R = Aryl); a consequence is that the "aromatic" 2,3- and 5,6-CC bonds of R(3) approximate to being double bonds. Multinuclear NMR spectra in C(6)D(6) and C(7)D(8) show that 1 and 2 exhibit dynamic behaviour. [The following abbreviations are used: L(1) = N(SiMe(3))C(Ph)N(SiMe(3)); L(2) = N(SiMe(3))C(C(6)H(4)Me-4)N(Ph); tmeda = (Me(2)NCH(2)-)(2); thf = tetrahydrofuran.] This reduction is further supported by a DFT analysis.     

(MeLi)4(dem)1.5]infinity] and [(thf)3Li3M3[(NtBu)3S--how to reduce aggregation of parent methyllithium

Organolithium compounds play the leading role among the organometallic reagents in synthesis and in industrial processes. Up to date industrial application of methyllithium is limited because it is only soluble in diethyl ether, which amplifies various hazards in large-scale processes. However, most reactions require polar solvents like diethyl ether or THF to disassemble parent organolithium oligomers. If classical bidentate donor solvents like TMEDA (TMEDA= N,N,N',N'tetramethyl-1,2-ethanediamine) or DME (DME=1,2-dimethoxyethane) are added to methyllithium, tetrameric units are linked to form polymeric arrays that suffer from reduced reactivity and/or solubility. In this paper we present two different approaches to tune methyllithium aggregation. In [[(MeLi)4(dem)1,5)infinity] (1; DEM = EtOCH2OEt, diethoxymethane) a polymeric architecture is maintained that forms microporous soluble aggregates as a result of the rigid bite of the methylene-bridged bidentate donor base DEM. Wide channels of 720 pm in diameter in the structure maintain full solubility as they are coated with lipophilic ethyl groups and filled with solvent. In compound 1 the long-range Li3CH3...Li interactions found in solid [[(MeLi)4]infinity] are maintained. A different approach was successful in the disassembly of the tetrameric architecture of [((MeLi)4]infinity]. In the reaction of dilithium triazasulfite both the parent [(MeLi)4] tetramer and the [[Li2[(NtBu)3S]]2] dimer disintegrate and recombine to give an MeLi monomer stabilized in the adduct complex [(thf)3Li3Me-[(NtBu)3S]] (2). One side of the Li3 triangle, often found in organolithium chemistry, is shielded by the tripodal triazasulfite, while the other face is mu3-capped by the methanide anion. This Li3 structural motif is also present in organolithium tetramers and hexamers. All single-crystal structures have been confirmed through solid-state NMR experiments to be the same as in the bulk powder material.     

Solution and solid-state structure of the anion [Ag(2)[closo-CB(11)H(12)](4)](2-)

Addition of the carbene 1,3-dimesitylimidazol-2-ylidene (IMes) to a toluene solution of Ag[closo-CB(11)H(12)] results in the formation of the complex [(IMes)(2)Ag](2)[Ag(2)[closo-CB(11)H(12)](4)], the anionic component of which contains two silver(I) centers bridged by two carboranes in addition to one terminally bound carborane on each metal, in the solid-state. Comparison of the observed (11)B[(1)H] NMR chemical shifts of [(IMes)(2)Ag](2)[Ag(2)[closo-CB(11)H(12)](4)] or Ag[closo-CB(11)H(12)] with [NBu(4)][closo-CB(11)H(12)] in CD(2)Cl(2) demonstrates that the silver ion interacts significantly with the cage in solution. Theoretical investigations using the ab initio/GIAO/NMR method of [closo-CB(11)H(12)](-) and Na[closo-CB(11)H(12)] as model geometries for the silver salts support experimental evidence for these Ag...[BH] interactions in solution.     

Preparation and Crystal Structure of the Neodymium Borohydride [Li(thf)4]2[Nd2(μ‐Cl)2(BH4)6(thf)2]

The neodymium borohydride [Li(thf)₄]₂[Nd₂(μ‐Cl)₂(BH₄)₆(thf)₂] was synthesized from neodymium chloride and lithium borohydride. The compound crystallized in the triclinic crystal system, space group (No. 2) with the cell constants a = 14.8613(11), b = 17.8715(13), c = 23.5846(18) Å, α = 100.760(6), β = 90.648(6) and γ = 103.294(6)°. Each neodymium atom is coordinated by three borohydride anions and a THF molecule whereas two neodymium cations are bridged through two chloro ligands. The charge of the [Nd₂(μ‐Cl)₂(BH₄)₆(thf)₂]²⁻ anion, which represents the first structurally characterized binuclear mixed borohydride chlorido complex, is compensated by two [Li(thf)₄]⁺ cations.     

Uranium (III) scorpionates: synthesis and structure of [(TpMe2)2U[N(C6H5)2]] and [(TpMe2)2U[N(SiMe3)2]

Reaction of [(Tp(Me)2)(2)UI] with KNR(2) (R = C(6)H(5), SiMe(3)) in tetrahydrofuran (THF) afforded the monomeric trivalent actinide amide complexes [(Tp(Me)2)(2)U[N(C(6)H(5))(2)]], 1, and [(Tp(Me)2)(2)U[N(SiMe(3))(2)]], 2. The complexes have been fully characterized by spectroscopic methods and their structures were confirmed by X-ray crystallographic studies. In the solid state 1 and 2 exhibit distorted pentagonal bipyramidal geometries. The U-NR(2) bond lengths in both complexes are the same but in complex 2 the greater steric demands of the N(SiMe(3))(2) ligand led to elongated U-N(pz) bonds, especially those opposite the amido ligand.