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.     

Reaction of the silylene Si[(NCH2But)2C6H4-1,2] with the alkali metal silylamides M[N(SiMe3)R](M = Li, Na or K; R = SiMe3 or SiMe2Ph)

The thermally stable silylene Si[(NCH(2)Bu(t))(2)C(6)H(4)-1,2] 1 undergoes oxidative addition reactions with the alkali metal silylamides MN(SiMe(3))(2)(M = Li, Na or K) to afford the new alkali metal amides MN(SiMe(3))[(1)SiMe(3)][M = Li (2), Na (3) or K (4)]. Reaction of two equivalents of 1 with LiN(R)(SiMe(3)) leads in a two-step process to the compound LiN[(1)R][(1)SiMe(3)][R = SiMe(2)Ph (5) or SiMe(3) (6)]. Alternatively, 1 reacts with 3 to afford NaN[(1)SiMe(3)](2) (7). The structures of 2-5 and are presented and the formation of 2-7 is discussed.     

Synthesis and structures of crystalline Li, Al and Sn(II) 1-azaallyls and beta-diketiminates derived from [Li{mu,eta3-N(SiMe3)C(Ad)C(H)SiMe3}]2 (Ad = 1-adamantyl)

The crystalline dimeric 1-azaallyllithium complex [Li{mu,eta(3-N(SiMe3)C(Ad)C(H)SiMe3}]2 (1) was prepared from equivalent portions of Li[CH(SiMe3)2] and 1-cyanoadamantane (AdCN). Complex was used as precursor to each of the crystalline complexes 2-8 which were obtained in good yield. By 1-azaallyl ligand transfer, 1 afforded (i) [Al{eta3-N(SiMe3)C(Ad)C(H)SiMe3}{kappa1-N(SiMe3)C(Ad)=C(H)SiMe3-E}Me] (5) with [AlCl2Me](2), (ii) [Sn{eta3-N(SiMe3)C(Ad)C(H)SiMe3}2] (7) with Sn[N(SiMe3)2]2, and (iii) [Li(N{C(Ad)=C(H)SiMe3-E}{Si(NN)SiMe3})(thf)2] (8) with the silylene Si[(NCH(2)Bu(t))2C6H(4)-1,2] [= Si(NN)]. By insertion into the C[triple bond, length as m-dash]N bond of the appropriate cyanoarene RCN, gave the beta-diketiminate [Li{mu-N(SiMe3)C(Ad)C(H)C(R)NSiMe3}]2 [R = Ph (2), C(6)H(4)Me-4 (3)], and yielded [Al{kappa2-N(SiMe3)C(Ad)C(H)C(Ph)NSiMe3}{kappa1-N(SiMe3)C(Ad)=C(H)SiMe3-E}Me] (6). The beta-diketiminate [Al{kappa2-N(SiMe3)C(Ad)C(H)C(Ph)NSiMe3}Me2] (4) was prepared from 2 and [AlClMe2]2. The X-ray structures of 1 and 3-8 are presented. Multinuclear NMR spectra in C6D6 or C6D5CD3 have been recorded for each of 1-8; such data on 8 revealed that in solution two minor isomers were also present.     

Reactions between a sodium amide Na[N(SiMe3)R1] (R1 = SiMe3, SiMe2Ph or But) and a cyanoalkane RCN (R = Ad or Bu(t))

Reactions between sodium amides Na[N(SiMe3)R1] [R1 = SiMe3 (1), SiMe2Ph (2) or But (3)] and cyanoalkanes RCN (R = Ad or But) were investigated. In each case the nitrile adduct [Na{mu-N(SiMe3)2}(NCR)]2 [R = Ad (1a) or But (1b)], trans-[Na{mu-N(SiMe3)(SiMe2Ph)}(NCR)]2 [R = Ad (2a) or But (2b)], [(Na{mu-N(SiMe3)But})3(NCAd)3] (3a) or [(Na{mu-N(SiMe3)But})3(NCBut)n] [n = 3 (3b) or 2 (3c)] was isolated. The reaction of complexes 3a or 3b with benzene afforded the ketimido complex [Na{mu-N=C(Ad)(Ph)}]6.2C6H6 (4a) or [Na{mu-N=C(But)(Ph)}]6 (4b); the former was also prepared in more conventional fashion from NaPh and AdCN. The synthesis and structure of an analogue of complex 1a, [Li{mu-N(SiMe3)2}(NCAd)]2 (5a), is also presented. The compounds 1a, 1b, 2a, 2b, 3, 3b, 4a, 4b and 5a were characterised by X-ray diffraction.     

Sterisch abgeschirmte Nitridokomplexe von Molybdän und Wolfram Die Kristallstrukturen von [MoN(NPh2)3] und [W4N4(NPh2)6(OnC4H9)2]

Stericly Shielded Nitrido Complexes of Molybdenum and Tungsten. The Crystal Structures of [MoN(NPh₂)₃] and [W₄N₄(NPh₂)₆(OⁿC₄H₉)₂] The reactions of MoNCl₃ and WNCl₃, respectively, with lithium diphenylamide in tetrahydrofurane produce the monomeric nitrido complexes MN(NPh₂)₃ with CN = 4 at the metal atoms. In the presence of lithium-n-butyl LiNPh₂ and WNCl₃ also form the tetrameric nitrido complex [W₄N₄(NPh₂)₆(OⁿC₄H₉)₂] which contains W^V and W^VI. The compounds are characterized by their i.r. spectra, by X-ray structural analysis, and, partially, by ¹H and ¹³C n.m.r. spectroscopy. MoN(NPh₂)₃: Space group P1 , Z = 2, 4060 observed independent reflexions, R = 0.031. Lattice dimensions at 20°C: a = 956.2(4) pm, b = 1 015.9(2) pm, c = 1 598.1(3) pm; α = 79.06(2)°, β = 85.67(3)°, γ = 82.57(3)°. The compound forms monomeric molecules with Mo?N bond lengths of 163.4 pm and mean Mo? NPh₂ distances of 199.2 pm. [W₄N₄(NPh₂)₆(OⁿC₄H₉)₂]: Space group P2₁/n, Z = 2, 1903 observed independent reflexions, R=0.039. Lattice parameters at 19°C: a = 1582.2(3) pm, b = 1182.4(2) pm, c = 2053.3(4) pm; β = 103.77(2)°. The compound forms centrosymmetric molecules, in which the central W–W dumb-bell (bond length 253.5 pm) is linked by the nitrido ligands of two WN₂(NPh₂)₂=units in a T shaped order of the N-atoms.     

The reaction of Li[Al(OR)4] R = OC(CF3)2Ph, OC(CF3)3 with NO/NO2 giving NO[Al(OR)4], Li[NO3] and N2O. The synthesis of NO[Al(OR)4] from Li[Al(OR)4] and NO[SbF6] in sulfur dioxide solution

NO[Al(OC(CF(3))(2)Ph)(4)] 1 and NO[Al(OC(CF(3))(3))(4)] 2 were obtained by the metathesis reaction of NO[SbF(6)] and the corresponding Li[Al(OR)(4)] salts in liquid sulfur dioxide solution in ca 40% (1) and 85% (2) isolated yield. 1 and 2, as well as Li[NO(3)] and N(2)O, were also given by the reaction of an excess of mixture of (90 mol%) NO, (10 mol%) NO(2) with Li[Al(OR)(4)] followed by extraction with SO(2). The unfavourable disproportionation reaction of 2NO(2)(g) to [NO](+)(g) and [NO(3)](-)(g)[DeltaH degrees = +616.2 kJ mol(-1)] is more than compensated by the disproportionation energy of 3NO(g) to N(2)O(g) and NO(2)(g)[DeltaH degrees =-155.4 kJ mol(-1)] and the lattice energy of Li[NO(3)](s)[U(POT)= 862 kJ mol(-1)]. Evidence is presented that the reaction proceeds via a complex of [Li](+) with NO, NO(2)(or their dimers) and N(2)O. NO(2) and Li[Al(OC(CF(3))(3))(4)] gave [NO(3)(NO)(3)][Al(OC(CF(3))(3))(4)](2), NO[Al(OC(CF(3))(3))(4)] and (NO(2))[Al(OC(CF(3))(3))(4)] products. The aluminium complex [Li[AlF(OC(CF(3))(2)Ph)(3)]](2) 3 was prepared by the thermal decomposition of Li[Al(OC(CF(3))(2)Ph)(4)]. Compounds 1 and 3 were characterized by single crystal X-ray structural analyses, 1-3 by elemental analyses, NMR, IR, Raman and mass spectra. Solid 1 contains [Al(OC(CF(3))(2)Ph)(4)](-) and [NO](+) weakly linked via donor acceptor interactions, while in the SO(2) solution there is an equilibrium between the associated [NO](+)[Al(OC(CF(3))(2)Ph)(4)](-) and separated solvated ions. Solid 2 contains essentially ionic [NO](+) and [Al(OC(CF(3))(3))(4)](-). Complex 3 consists of two [Li[AlF(OC(CF(3))(2)Ph)(3)]] units linked via fluorine lithium contacts. Compound 1 is unstable in the SO(2) solution and decomposes to yield [AlF(OC(CF(3))(2)Ph)(3)](-), [(PhC(CF(3))(2)O)(3)Al(mu-F)Al(OC(CF(3))(2)Ph)(3)](-) anions as well as (NO)C(6)H(4)C(CF(3))(2)OH, while compound 2 is stable in liquid SO(2). The [small nu](NO(+)) in 1 and [NO](+)(toluene)[SbCl(6)] are similar, implying similar basicities of [Al(OC(CF(3))(2)Ph)(4)](-) and toluene.     

Tetraammin-Lithium-Kationen zur Stabilisierung phenylsubstituierter Zintl-Anionen: Die Verbindung [Li(NH3)4]2[Sn2Ph4]

Tetraammine Lithium Cations Stabilizing Phenylsubstituted Zintl-Anions: The Compound [Li(NH₃)₄]₂[Sn₂Ph₄] Ruby-red, brittle single crystals of [Li(NH₃)₄]₂[Sn₂Ph₄] were synthesized by the reaction of diphenyltin dichloride and metallic lithium in liquid ammonia at ?35°C. The structure was determined from X-ray singlecrystal diffractometer data: Space group, P1 , Z = 1, a = 9.462(2) Å, b = 9.727(2) Å, c = 11.232(2) Å, α = 66.22(3)°, β = 85.78(3)°, γ = 61.83(3)°, R₁ (F ? 4σF) = 5.13%, wR₂ (F₀² ? 4σF) = 10.5%, N(F ? 4σF) = 779, N(Var.) = 163. The compound contains to Sb₂Ph₄ isosteric centres [Sn₂Ph₄]^2? as anions which are connected to rods by lithium cations in distorted tetrahedral coordination by ammonia. These rods are arranged parallel to one another in the b,c-plane, but stacked along [100].     

The Binary Group 4 Azides [PPh4]2[Zr(N3)6] and [PPh4]2[Hf(N3)6]

The binary zirconium and hafnium polyazides [PPh₄]₂[M(N₃)₆] (M=Zr, Hf) were obtained in near quantitative yields from the corresponding metal fluorides MF₄ by fluoride–azide exchange reactions with Me₃SiN₃ in the presence of two equivalents of [PPh₄][N₃]. The novel polyazido compounds were characterized by their vibrational spectra and their X‐ray crystal structures. Both anion structures provide experimental evidence for near‐linear M‐N‐N coordination of metal azides. The species [M(N₃)₄], [M(N₃)₅]^? and [M(N₃)₆]^2? (M=Ti, Zr, Hf) were studied by quantum chemical calculations at the electronic structure density functional theory and MP2 levels.     

Strukturen von planaren und tetraedrischen TetrafulminatoMetallkomplexen: [N(C3H7)4]2 [Ni(CNO)4], [N(C3H7)4]2 [Pt(CNO)4] und [N(C3H7)4]2 [Zn(CNO)4]

Pseudohalogeno Metal Compounds. LXXVIII. Structures of Planar and Tetrahedral Tetrafulminato Metal Complexes: [N(C₃H₇)₄]₂ [Ni(CNO)₄], [N(C₃H₇)₄]₂ [Pt(CNO)₄], and [N(C₃H₇)₄]₂ [Zn(CNO)₄] The crystals contain the tetrafulminatometallates of an ideal square planar structure ([Ni(CNO)₄]^2–, [Pt(CNO)₄]^2–) with D_4h symmetry at the nickel and platinum atom and a tetrahedron ([Zn(CNO)₄]^2–) with perfect T_d symmetry at the zinc atom and with linear C≡N–O ligands. The metal carbon bonds (Ni–C: 187 pm, Pt–C: 200 pm, Zn–C: 201 pm) of the metal fulminates are very close to those of the corresponding cyano complexes. In the crystals the anions ([Ni(CNO)₄]^2–, [Pt(CNO)₄]^2–, [Zn(CNO)₄]^2–) are separated by the cations ([N(C₃H₇)₄]⁺) which explains the thermal stability of these compounds.     

Der erste Metallkomplex mit neutralem 1,2-Bis(phenyltriazeno)benzol als Ligand: Synthese und Struktur von [Cd{PhN3(H)C6H4N3(H)Ph}{PhN3C6H4N3(H)Ph}2]

The First Metal Complex with Neutral 1,2-Bis(phenyltriazeno)-benzene as Ligand: Synthesis and Crystal Structure of [Cd{PhN₃(H)C₆H₄N₃(H)Ph}{PhN₃C₆H₄N₃(H)Ph}₂] [Cd{PhN₃(H)C₆H₄N₃(H)Ph}{PhN₃C₆H₄N₃(H)Ph}₂] is obtained in aqueous ammonia by the reaction of CdSO₄ with an excess of 1,2-bis(phenyltriazeno)benzene. It forms orange red, air stable prismatic crystals with the monoclinic space group P2₁/c and a = 1217.7(2); b = 2161.8(6); c = 2008.3(5) pm; β = 100.07(6)º; Z = 4. The compound is composed of mononuclear complexes in which the Cd atom is coordinated by one chelating bis(phenyltriazeno)benzene and two monodentate 1-phenyltriazenido-2-phenyltriazeno benzene anions in a distorted tetrahedral arrangement. The Cd—N distances are in the range of 220.7 to 239.7 pm.     

Hydroxoverbindungen. 10. Über die Natriumoxohydroxostannate(II) Na4[Sn4O(OH)10] und Na2[Sn2O(OH)4]

Hydroxo Compounds. 10. The Sodium Oxohydroxostannates(II) Na₄[Sn₄O(OH)₁₀] and Na₂[Sn₂O(OH)₄] Na₄[Sn₄O(OH)₁₀] = Na₄[Sn(OH)₃]₂[Sn₂O(OH)₄] ( I ) and Na₂[Sn₂O(OH)₄] ( II ) have now been doubtlessly characterized as the first Na-hydroxostannates(II). I crystallizes monoclinic in P2₁/n (a = 1522.4(5) pm, b = 830.0(2) pm, c = 1276.0(3) pm, β = 104.8(2)°, Z = 4, R = 0.047, 1137 I_hkl); II crystallizes orthorhombic in P2₁2₁2₁ (a = 1450(2) pm, b = 1665(2) pm, c = 590.7(8) pm, Z = 8, R = 0.042, 1208 I_hkl). II is identical with the compound which was described up to now as “Na[Sn(OH)₃]”. The new compounds contain the complex anions [Sn(OH)₃]^? and [Sn₂O(OH)₄]^2?, whose structures are now proved. The oxotetrahydroxo-distannate(II) anion [Sn₂O(OH)₄]^2? exhibits a syn-conformation with respect to the projection along the (Sn? Sn) vector. The two compounds crystallize with pronounced layer structures, which show direct topotactical relations with one another as well as with SnO. This relates closely to the fast formation of SnO from crystals of I and II .     

Magnesium(II) complexes of 2,4-N,N'-disubstituted 1,3,5-triazapentadienyl ligands: synthesis and characterization of [N(Dipp)C(NMe2)NC(NMe(2))N(SiMe3)MgBr]2 and [N(R)C(R')NC(R')N(SiMe3)]2Mg (Dipp = 2,6-iPr2-C6H3, R = Ph, SiMe(3); R' = NMe2, 1-piperidino)

Treatment of the appropriate lithium or sodium 2,4-N,N'-disubstituted 1,3,5-triazapentadienate [RNC(R')NC(R')N(SiMe(3))M](2) (R = Ph, 2,6-(i)Pr(2)-C(6)H(3)(Dipp) or SiMe(3); R' = NMe(2) or 1-piperidino; M = Li or Na) with one or half equivalent portion of MgBr(2)(THF)(2) in Et(2)O under mild conditions furnishes in good yield the first structurally characterized molecular magnesium 2,4-N,N'-disubstituted 1,3,5-triazapentadienates [DippNC(NMe(2))NC(NMe(2))N(SiMe(3))MgBr](2) (1), [{RNC(R')NC(R')N(SiMe(3))}(2)Mg] (R = Ph, R' = NMe(2) 2; R = Ph, R' = 1-piperidino 3; R = SiMe(3), R' = 1-piperidino 4). The solid-state structure of 1 is dimeric and those of 2, 3, and 4 are monomeric. The ligand backbone NCNCN in 1 adopts a W-shaped configuration, while in 2, 3 and 4 adopts a U-shaped configuration.     

Schwingungs-Resonanz-Raman-Spektren von [n-(C4H9)4N]2[OsBr6] bei 77 K

Vibrational Resonance Raman Spectra of [n-(C₄H₉)₄N]₂[OsBr₆] at 77 K A rotating Raman cell in the 180° scattering geometry is described. It permits the measurement of Raman spectra of deeply coloured solids and liquids at the temperature of liquid nitrogen. Meaningful polarization measurements on solid samples are obtained by the use of optically isotropic pellets of tetraalkylammonium complex salts. In the solid state [n-(C₄H₉)₄N]₂[OsBr₆] displays a rigorous resonance Raman effect. Especially the excitation at 454.4 and 457.9 nm coincides with an intense electric dipole allowed charge-transfer transition of the anion, so that as far as nine overtones of the totally symmetric stretching vibration A_1g and many combination tones of this vibration with the other ra-active fundamentals are to be observed. The determination of the spectroscopic constants ω₁ and x₁₁ demonstrates, that the deviations from the harmonic oscillator are within the limit of error.