Reaktionen von NaAlH4 mit primären Silylphosphanen und ‐arsanen: Synthese und Kristallstruktur eines cyclischen Natriumphosphanylalanats und eines polycyclischen Natriumarsanylalanats

Reaction of NaAlH4 with Primer Silylphosphines and Silylarsines: Synthesis and Crystal Structure of a Cyclic Sodium Phosphanylalanate and a Polycyclic Sodium Arsanylalanate The reaction of sodium aluminium hydride with H₂PSiMe₃ in the molar ratio 1:4 yields the compound [H₂Al{P(SiMe₃)₂}₂Na(dme)₂] ( 1 ). Central structural motif of this compound in a four‐membered AlP₂Na ring. Surprisingly the phosphorus atoms in the ring wear two exocyclic silylgroups each. From the reaction of NaAlH₄ with the primer silylarsine H₂AsSiiPr₃ in THF the ionic compound 2 can be obtained. In this compound cyclic [(H₂Al)₃(AsSiiPr₃)₃]^3‐ anions coordinate the sodium counter‐ions by the hydride ligands as well as by the arsenic atoms.     

Ligandstabilisierte cyclische und polycyclische Aluminium‐Phosphor‐ und Aluminium‐Arsen‐Verbindungen

Ligand Stabilized Cyclic and Polycyclic Aluminium Phosphorus and Aluminium Arsenic Compounds The reaction of AlCl₃ with Li₂AsSiRMe₂ (R = CMe₂iPr) in a mixture of ether and heptane yields the ether stabilized polycyclic compound [(AlCl)₄(AsSiRMe₂)₄(Et₂O)₂] ( 4 ) with a ladder shaped Al₄As₄ core structure. The shape of 4 is mostly similar to the aluminium phosphorus compound [(AlCl)₄(PSiiPr₃)₄(Et₂O)₂] ( 1 ) described recently [1]. These two compounds 1 and 4 can be cleaved into the cyclic compounds [{AlCl(C₅H₅N)}₂(PSiiPr₃)₂] ( 3 ) and [{AlCl(NEt₃)}₂(AsSiRMe₂)₂] ( 5 ) by reaction with pyridine and NEt₃, respectively. The compounds 3 , 4 , and 5 have been characterized by single crystal X‐ray diffraction.     

(Ph4P)2[Be2F6]·2CH3CN: Synthese,Schwingungsspektrum, Kristallstruktur und quantenchemische Rechnungen

(Ph₄P)₂[Be₂F₆]·2CH₃CN: Synthesis, IR Spectra, Crystal Structure, and Quantum Chemical Calculations The hexafluorodiberyllate (Ph₄P)₂[Be₂F₆]·2CH₃CN ( 1 ) was prepared by the reaction of (Ph₄P)₂[Be₂Cl₆] with excess silver(I) fluoride in acetonitrile solution. According to the IR spectra and to the X‐ray crystal structure determination, 1 contains isolated [Be₂F₆]^2? ions of symmetry C_i, which is very close to symmetry D_2h. 1 crystallizes triclinically in space group with one formula unit per unit cell. Lattice dimensions at 193 K: a = 950.5(2), b = 1016.1(2), c = 1305.2(2) pm, α = 101.04(2)°, β = 110.83(2)°, γ = 96.85(2)°, R₁ = 0.0354. DFT (BP86) and ab initio (CCSD(T)) calculations with large basis sets provide the picture of an intrinsically unstable molecule stabilized by solvent and solid state effects.     

Bisaminophosphane – Synthese,Struktur und Reaktivität

Bisaminophosphanes – Synthesis, Structure, and Reactivity Different pathways for the synthesis of bis(alkylamino)phosphanes RP(N(H)R′)₂ are described. t‐BuP(N(H)‐ Dipp)₂ (Dipp = 2,6‐i‐Pr₂–C₆H₃) was structurally characterized by single crystal X‐ray diffraction. The reactivity of the compounds was examplarily investigated using t‐BuP(N(H)t‐Bu)₂. Its reaction with Me₃Al and R₂AlH (R = Me, Et, i‐Bu) in 1 : 1 and 1 : 2 stoichiometrie yield monosubstituted compounds of the type t‐BuP(N(H)t‐Bu)(N(AlR₂)t‐Bu).     

Der erste viergliedrige Al/P‐Ring,der von drei Phosphoratomen und einem Aluminiumatom gebildet wird: Synthese und Kristallstruktur von [Cp*Al(PtBu)3]

The First Four‐Membered Al/P Ring formed by three Phosphorus Atoms nd one Aluminium Atom: Synthesis and Crystal Structure of [Cp*Al(P t Bu)₃] (AlCp*)₄ reacts with (PtBu)₃ at 90 °C to form the new cyclic Al/P‐compound 1,2,3‐tris‐t‐butyl‐tri‐phospha‐4‐pentamethylcyclopentadienylaluminetane: [Cp*Al(PtBu)₃] ( 1 ). 1 has been characterised by single crystal x‐ray diffraction, ³¹P{¹H}‐NMR spectroscopy as well as mass spectroscopy. It consists of a folded four‐membered AlP₃‐ring and differs therefore from all Al/P‐compounds known so far, which always show alternating Al‐P‐positions. 1 crystallises in the orthorhombic spacegroup P2₁2₁2₁, the lattice constants are: a = 9.067 pm, b = 16.212 pm, c = 17.449 pm, α = β = γ = 90°.     

K4[PbSe4]⋅en⋅NH3: A Non‐Oxide,Non‐Halide Inorganic Lead(IV) Compound

The first inorganic lead(IV) compound without oxygen, nitrogen or halogen ligands attached to the lead atom was obtained as the potassium salt of the tetraselenidoplumbate(IV) anion [Pb^IVSe₄]^4?. It is stable under inert conditions which may enable the transfer of the chemistry of chalcogenidogermanate(IV) or chalcogenidostannate(IV) materials, to the lead homologues.     

Die Hydroaluminierung von 1,1,4,4‐Tetramethyl‐2,3‐diazabutadien mit Dialkylaluminiumhydriden – Synthese von Dialkylaluminiumhydrazoniden

The Hydroalumination of 1,1,4,4‐Tetramethyl‐2,3‐diazabutadiene by Dialkylaluminium Hydrides – Synthesis of Dialkylaluminium Hydrazonides 1,1,4,4‐Tetramethyl‐2,3‐diazabutadiene reacted with dimethylaluminium hydride by hydroalumination of only one C=N double bond. The hydrazone derivative [Me₂Al–N(CHMe₂)–N=CMe₂]₂ ( 1 ) was formed which gave a dimer possessing a six‐membered Al₂N₄ heterocycle. The hydroalumination of both C=N double bonds was not observed. Also an excess of di(tert‐butyl)‐ or bis(trimethylsilylmethyl)aluminium hydride afforded only the product of a single hydroalumination step, a second dialkylaluminium hydride molecule was attached via a coordinative interaction between its central aluminium atom and the nitrogen atom of the C=N double bond and in addition via a 3 c‐2 e Al–H–Al bond. Compounds [(Me₃C)₂Al][(Me₃C)₂AlH]N(CHMe₂)NCMe₂ ( 2 ) and [(Me₃SiCH₂)₂Al][(Me₃SiCH₂)₂AlH]N(CHMe₂)NCMe₂ ( 3 ) were formed which have five‐membered Al₂N₂H heterocycles. Thermolysis of 2 gave by C–H activation compound [(Me₃C)₂Al]₂[CH₂C(Me)=N–]₂ ( 4 ) in trace amounts which possesses two anellated AlN₂C₂ rings with a common N–N bond. In contrast, the thermal decomposition of 3 yielded by the cleavage of the N–N bond a dimeric dialkylaluminium methylideneamide ( 5 ) which has two intact C=N double bonds. Up to now our attempts to insert a C=N double bond into an Al–C bond remained unsuccessful, and only the formation of an adduct [(Me₃C)₃Al(–N=CMe₂)₂] ( 6 ) was observed upon treatment of tri(tert‐butyl)aluminium with the diazabutadiene derivative.     

Synthese und Struktur von Sr6P8‐Polyedern in gemischten Phosphaniden/Phosphandiiden des Strontiums

Synthesis and Structures of Sr₆P₈ Polyhedra in Mixed Phosphanides/Phosphandiides of Strontium The strontiation of H₂PSiⁱPr₃ ( 1 ) with (THF)₂Sr[N(SiMe₃)₂]₂ in THF yields colorless tetrakis(tetrahydrofuran‐O)strontium bis(triisopropylsilylphosphanide) ( 3 ). The central alkaline earth metal atom has an octahedral environment with the phosphanide ligands in trans position. The homometalation in toluene leads to the elimination of 1 and THF. Cooling of this solution gives crystals of colorless tetrakis(tetrahydrofuran‐O)hexastrontium‐tetrakis(triisopropylsilylphosphanide)‐tetrakis(triisopropylsilylphosphandiide) ( 4 ). The equimolar reaction of H₂PSi^tBu₃ ( 2 ) with (THF)₂Sr[N(SiMe₃)₂]₂ in toluene yields in the first step heteroleptic dimeric {(Me₃Si)₂NSr(THF)₂[P(H)Si^tBu₃]}₂ ( 5 )₂. This compounds monomerizes in THF to (Me₃Si)₂N–Sr(THF)₄[P(H)Si^tBu₃] ( 6 ), which forms an equilibrium with the homoleptic dismutation products (THF)₂Sr[N(SiMe₃)₂]₂ and (THF)₄Sr[P(H)Si^tBu₃]₂ ( 7 ). Compound ( 5 )₂ undergoes a intramolecular strontiation and bis(tetrahydrofuran‐O)hexastrontium‐tetrakis[tri(tert‐butyl)silylphosphanide]‐tetrakis[tri(tert‐butyl)silylphosphandiide] ( 8 ) is isolated. The central Sr₆P₈‐polyhedra of 4 and 8 are very similar.     

Molekulare Verbindungen mit SiAl4-, SiAl3- und GeAl4-Einheiten: Synthese und Struktur von Si(AlCl2 · OEt2)4, Ge(AlCl2 · OEt2)4 und HSi(Cp*AlBr)3

Molecular Compounds containing SiAl₄, SiAl₃, and GeAl₄ Units: Sythesis and Structure of Si(AlCl₂ · OEt₂)₄, Ge(AlCl₂ · OEt₂)₄, and HSi(Cp*AlBr)₃ In the scope of our investigations of the reactivity and the potential for synthesis of solutions of Al^I halides we performed reactions between these solutions and SiCp or GeCp, respectively. From these reactions we could isolate an unusual cluster with a central Al₁₄Si unit, described elsewhere, and the compounds Si(AlCl₂ · OEt₂)₄, Ge(AlCl₂ · OEt₂)₄, and HSi(Cp*AlBr)₃, which will be presented and discussed here. In these species the Si respectively the Ge atoms are connected to 4 respectively 3 Al atoms. This bonding results in strong negative polarized Si/Ge centres. The change of the polarization with respect to “normal” Si–R or Ge–R linking leads to a drastic weakening of the Si–R respectively the Ge–R bonds.     

Ein neues Phosphorsulfid mit Adamantangerüst: δ‐P4S7

A New Phosphorus Sulfide with Adamantane Structure: δ‐P₄S₇ By sulfur abstraction from α‐P₄S₉/P₄S₁₀ with triphenylphosphine a new phosphorus sulfide δ‐P₄S₇ with adamantane skeleton and an additional sulfur in exo‐position was identified in CS₂‐solution by ³¹P‐NMR spectroscopy. Product distribution and ³¹P‐NMR parameter are given.     

Die Reaktion von SeCl4 mit Übergangsmetalltetrachloriden. Synthese und Kristallstrukturen von (SeCl3)2MCl6 mit M = Zr,Hf, Mo,Re

The Reaction of SeCl₄ with Transition Metal Tetrachlorides. Synthesis and Crystal Structures of (SeCl₃)₂MCl₆ with M = Zr, Hf, Mo, Re The transition metal tetrachlorides ZrCl₄, HfCl₄ and MoCl₄ react with SeCl₄ in closed ampoules at temperatures of 140°C to (SeCl₃)₂MCl₆ (M = Zr, Hf, Mo) which are all isotypic and crystallize in the (SeCl₃)₂ReCl₆ structure type (orthorhombic, Fdd2, Z = 8, lattice constants for M = Zr: a = 1165.7(1)pm, b = 1287.2(2)pm, c = 2180.2(2)pm; for M = Hf: a = 1162.9(2)pm, b = 1285.0(2)pm, c = 2178.2(3)pm; for M = Mo: a = 1153.8(1)pm, b = 1267.7(1)pm, c = 2147.4(2)pm). The Cl^? ions form a hexagonal closest packing with one fourth of the octahedral holes filled by Se⁴⁺ and M⁴⁺ in an ordered way. The MCl₆ octahedra are regular, the SeCl₆ octahedra are distorted with 3 short and 3 long Se? Cl bonds (mean 215 pm and 287 pm). The structures can thus be regarded as built of SeCl₃⁺ and MCl₆^2? ions. Magnetic susceptibility measurements show for M = Zr the expected diamagnetic behavior, for M = Mo and Re paramagnetic behavior according to the Curie-Weiss law with magnetic moments of 2.5 B. M. for M = Mo and 3.7 B. M. for M = Re corresponding to 2 and 3 unpaired electrons respectivly.     

Synthese und Kristallstrukturen von 1,1,3,3‐Tetramethylimidazolinium‐dichlorid und 1,1,4‐Trimethylpiperazinium‐chlorid

Synthesis and Crystal Structures of 1,1,3,3‐Tetramethylimidazolinium Dichloride and 1,1,4‐Trimethylpiperazinium Chloride Single crystals of 1,1,3,3‐tetramethylimidazolinium dichloride ( 1 ) and 1,1,4‐trimethylpiperazinium chloride ( 2 ) were obtained by reaction of CH₂Cl₂ with tetramethylethylenediamine (TMEDA) and NNN′N″N″‐pentamethyldiethylenetriamine (PMDETA), respectively. Both compounds are characterized by single crystal X‐ray diffraction and by IR spectroscopy. 1: [C₇H₁₈N₂]Cl₂, space group P2₁/c, Z = 4, lattice dimensions at 193(2) K: a = 821.97(11), b = 1130.38(8), c = 1143.08(13) pm, β = 100.348(15)°, R₁ = 0.0271. The C₇N₂ heterocyclic ring has envelope conformation like other salts with this dication. 2: [C₇H₁₇N₂]Cl, space group P2₁2₁2₁, Z = 4, lattice dimensions at 100(2) K: a = 1030.37(8), b = 1036.55(6), c = 831.39(4) pm, R₁ = 0.0180. Although the heterocyclic mono‐cation is without site symmetry in the crystal, its molecular symmetry is close to C_s, forming chair conformation of the C₄N₂ six‐membered ring.     

Synthese und Charakterisierung neuer cyclischer und käfigartiger Indium‐Phosphor‐ und Indium‐Arsen‐Verbindungen

Synthesis and Characterization of New Cyclic and Cage‐like Indium — Phosphorus and Indium — Arsenic Compounds The reaction of InEt₃ with H₂ESiiPr₃ initially yields the cyclic compound [Et₂InP(H)SiiPr₃]₂ ( 2 ). 2 appears as a mixture of cis and trans isomers and has been characterized by ³¹P‐NMR spectroscopy, IR spectroscopy, and mass spectrometry. 2 decomposes in solution under elimination of ethane during a few days to form [EtInPSiiPr₃]₄ ( 3 ) with a cage‐like structure. The analogous arsenic compound [EtInAsSiiPr₃]₄ ( 4 ) can be prepared by reaction of InEt₃ with H₂AsSiiPr₃. Central structural motif of 3 and 4 is an In₄E₄ heterocubane like structure (E = P, As), whereas the reaction of InEt₃ with H₂PSiMe₂Thex (Thex = CMe₂iPr) yields [EtInPSiMe₂Thex]₆ ( 5 ) with a hexagonal prismatic structure.     

31P MAS-NMR an Phosphoroxidsulfiden — experimentelle Bestimmung und quantenchemische Berechnung der Tensoren der chemischen Verschiebung

³¹P MAS-NMR of Phosphorus Oxide Sulfides — Experimental Determination and Quantumchemical Calculation of Chemical Shift Tensors By high resolution solid state ³¹P MAS NMR and analysis of spinning sidebands the principal values of the chemical shift tensors in the series P₄O₆S_n with n = 0–4 have been determined. The orientations of the corresponding principal axes within the molecules have been derived. All magnetic shielding tensors show axial symmetry within the limits of experimental error. Thus the orientation of the shielding tensor within the molecules can be deduced indirectly. This information is usually not accessible for polycrystalline samples. The principal values of the tensor of the trivalent phosphorus atoms in P₄O₆S seem to deviate considerably from those of the other compounds with respect to anisotropy and axiality. The reason is a dynamic effect: the rotation of the molecule about the PS bond. All experimental results are confirmed by ab-initio calculations using the IGLO method.     

Lewis-Säure-Base-Reaktionen von Goldtrihalogeniden mit Bismuttrihalogeniden – Synthese und Kristallstrukturen von AuBiX6 (X  Cl,Br)

Lewis-Acid-Base-Reactions of Gold Trihalides with Bismuth Trihalides – Synthesis and Structures of AuBiX₆ (X ? CI, Br) Gold trihalides AuX₃ (X ? Cl, Br) react with bismuth trihalides in sealed glass ampoules to the 1 : 1 adducts AuBiX₆ (X ? Cl, Br). AuBiCl₆ is obtained by a chemical transport reaction at 220°C, whereas AuBiBr₆ was synthesized by solvothermal reaction in SiBr₄ at 150°C. Both compounds crystallize triclinic, space group P1 , Z = 4. AuBiCl₆; a = 698.3(4) pm; b = 1009.3(5) pm; c = 1381(1) pm; α = 104.98(5)°; β = 94.73(5)°; γ = 110.06(3)°; V = 867(1) · 10⁶ pm³. AuBiBr₆: a = 735.7(4) pm; b = 1055.7(5) pm; c = 1445(1) pm; α =104.88(5)°; β = 94.25(5)°; γ = 110.18(4)°; V =1001(1) ·10⁶pm³. The structures are build formally of square-planar [AuX₄]^? and chains of edge-connected ([BiX_4/2]⁺)_n units. Since each Bi ion is surrounded by eight halogenide ions in a square-antiprismatic form, the structure can alternatively be described as consisting of chains of edge sharing ([BiX₄X_4/2]^3?)_n antiprisms connected by Au³⁺ ions.     

Synthese,Komplexbildung und Kristallstrukturen von Cyclotriphosphazenen mit N,N,N′,N′‐Tetramethylguanidingruppen

Synthesis, Complex Formation, and Crystal Structures of Cyclotriphosphazenes with N,N,N′,N′‐Tetramethylguanidine Groups The reactions of monochloropentaphenoxycyclotriphosphazene and hexachlorocyclotriphosphazene with N,N,N′,N′‐tetramethylguanidine yield the mono and tetra substituted products 2‐(N,N,N′,N′‐tetramethylguanidine)‐2,4,4,6,6‐pentaphenoxy‐2 λ⁵,4 λ⁵,6 λ⁵‐cyclotriphosphaza‐1,3,5‐trien ( 1 ) and 2,2‐dichlor‐4,4,6,6‐tetra‐(N,N,N′,N′‐tetramethylguanidine‐2 λ⁵,4 λ⁵,6 λ⁵‐cyclotriphosphaza‐1,3,5‐trien ( 2 ) respectively; no hexa functionalized product could be obtained, even with high excess of the nucleophile. Electron release from the exocyclic amino substituent reduces the acceptor ability of the phosphorus atoms. Reactions of ( 2 ) with copper(II) chloride and palladium(II) bis(acetonitrilo)dichloride yield metal complexes with a ligand : metal ratio of 1 : 2. The X‐ray structure analyses of N₃P₃Cl₂(NC(N(CH₃)₂)₂)₄ · 2 CuCl₂ ( 2 a ) and N₃P₃Cl₂(NC(N(CH₃)₂)₂)₄ · 2 PdCl₂ ( 2 b ) show that each metal atom is coordinated by two imino nitrogen atoms in geminal positions and two chloride atoms in a square planar arrangement.     

Koordinationspolymere mit Tris(4‐carboxyphenyl)‐phosphanoxid als Ligand – Synthese,Kristallstrukturen und topologische Untersuchungen

The solvothermal reaction of MnCl₂ · 4H₂O or CoCl₂ · 6H₂O with tris(4‐carboxyphenyl)‐phosphine oxide (H₃TPO), in DMF orDMA resulted in the four coordination polymers [M₃(tpo)₂(dmf)(H₂O)₂]( 1 : M = Mn; 2 : M = Co), (NMe₂H₂)[Mn₃Cl(HCO₂)(htpo)(tpo)(H₂O)] ( 3 ) and (NMe₂H₂)[Mn₃(tpo)₂(OAc)] ( 4 ). Structural characterization by X‐ray crystallography revealed that 1 – 4 form 3‐periodical infinite networks; after synthesis solvent molecules occupy the framework pores. The topologies of the networks in 1 , 2 and 3 are unprecedented in literature and are systematically characterized. Furthermore, these topologies could be derived from hexagonal close packing ( 1 , 2 ) and cubic close packing ( 3 ), respectively.Compounds 1 , 2 and 4 were synthesized as pure crystalline materials, their thermal behaviour was examined by TG/DTA measurements and temperature dependent PXRD. 1 , 2 and 4 show remarkable thermal stability with decomposition temperatures between 450 and 500 °C. Temperature dependent PXRD measurements of compounds 1 and 2 reveal a structural transition at 260 °C, framework 4 loses its crystallinity at 210 °C.