Dihydroxytrimethylstiboran – einige Eigenschaften und Struktur

Dihydroxytrimethylstiborane – Properties and Structure (CH₃)₃Sb(OH)₂ · H₂O ( 1 ) is prepared by reaction of (CH₃)₃SbCl₂ and NaOH. 1 reacts with CO₂ to yield [(CH₃)₃SbOH]₂CO₃ · 2 H₂O ( 2 ). Thermogravimetric investigations and mass spectra show that 1 and 2 decompose at low temperature and low pressure to H₂O, CO₂ and (CH₃)₃SbO. The crystal and molecular structures of 1 and 2 are determined. 1 crystallizes orthorhombic (Pbca) with a = 1185.2, b = 1069.6, c = 1207.6 pm and Z = 8. 2 crystallizes in the acentric monoclinic space group Cc with a = 657.3, b = 1168.5, c = 2048.2 pm, β = 95,33° and Z = 4. The infrared spectra are discussed with regard to the hydrogen bonding.     

BiGaIn2S6 – Synthese,Struktur und Eigenschaften

BiGaIn₂S₆ – Synthesis, Structure, and Properties The novel compound BiGaIn₂S₆ was obtained in the quaternary system Bi–Ga–In–S. BiGaIn₂S₆ forms red transparent platelets and exhibits a range of homogeneity between BiGa₁In₂S₆ and BiGa_0.8In_2.2S₆. The compound is a semiconductor with E_g(opt.) = 1.9 eV. – BiGaIn₂S₆ crystallizes monoclinically forming a new structure type (a = 1112.0 pm, b = 380.6 pm, c = 1228.0 pm, β = 116.30°, Z = 2, space group P2₁/m, no. 11). The S atoms form strongly corrugated 2 D fragments of the (hc)₂ sphere packing type. The In atoms occupy octahedral holes (d(In–S) = 262 pm) and the Ga atoms tetrahedral holes (d(Ga–S) = 234 pm) inside the 2 D-layers. The Bi atoms on the top of trigonal BiS₃ pyramids (d(Bi–S) = 265 pm) are at the periphery of the layers and have four additional S ligands from the neigbouring layer at much larger distances (d(Bi–S) = 319 pm). – The bonding of a Bi^III sulfide is analyzed for the first time by the Electron Localization Function (ELF).     

K3ReH6 – Synthese,Struktur und magnetische Eigenschaften

K₃ReH₆ – Synthesis, Structure, and Magnetic Properties K₃ReH₆ and K₃ReD₆ were synthesized by the reaction of potassium hydride (deuteride) with rhenium powder under a hydrogen pressure between 3000–3500 bar at 850 K. X-ray investigations on powdered samples and elastic neutron diffraction experiments on the deuterated compound at the triple axis spectrometer TAS 1 in the temperature range 5–600 K led to the atomic arrangement, which corresponds to that of the cryolite with [ReH₆]^3–-octahedra as characteristic units. Magnetic susceptibility measurements in the temperature range from 3.5 K and room temperature revealed a weak temperature independent paramagnetism. Quantum mechanical calculations confirm these facts and show in detail that the large value of the spin-orbit coupling parameter is essential for the magnetic behaviour.     

TiOBr; Darstellung,Eigenschaften und Struktur*

TiOBr was prepared by reaction of Ti with TiO₂ and Br₂. The compound forms fiat reddish-brown needles and shows a temperature independent weak paramagnetism. It crystallises in the orthorhombic system (Pmmn; a = 3.787, b = 3.487, c = 8.529 Å) with the FeOCl type of structure. The interatomic distances are Ti?O = 1.952; 2.245 Å (2X) and Ti?Br = 2.544 Å (2X).     

Plasmapolymerisierte Organosilane – Photolumineszenz,Infrarotabsorption und Struktur

Plasma Polymerized Organosilanes – Photoluminescence, Infrared Absorption and Structure The structure of amorphous hydrogen‐containing silicon‐carbon thin films (a‐Si_1–xC_x : H) is difficult to access as known for disordered materials. In this paper we attempt to develop structure models for a‐Si_1–xC_x : H from photoluminescence and infrared transmission, and to support these models through molecular dynamic and LCAO calculations. The modelling is further based on the knowledge of the starting materials in the plasma.     

Synthese,Struktur, Elektrochemie und optische Eigenschaften von alkinylfunktionalisierten 1,3,2‐Diazaborolen und 1,3,2‐Diazaborolidinen

Syntheses, Structures, Electrochemistry and Optical Properties of Alkyne‐Functionalized 1,3,2‐Diazaboroles and 1,3,2‐Diazaborolidenes The reaction of 2‐bromo‐1,3‐ditert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazaborole ( 3 ) with lithiated tert‐butyl‐acetylene and lithiated phenylacetylene affords the 2‐alkynyl‐functionalized 1,3,2‐diazaboroles 4 and 5 as a thermolabile colorless oil ( 4 ) or a solid ( 5 ). Similarly 2‐bromo‐1,3‐diethyl‐2,3‐dihydro‐1H‐1,3,2‐benzodiazaborole ( 6 ) was converted into the crystalline 2‐alkynyl‐benzo‐1,3,2‐diazaboroles 7 and 8 by treatment with LiC≡C–tBu or LiC≡CPh, respectively. 2‐Ethynyl‐1,3‐ditert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazaborole ( 2 ) was metalated with tert‐butyl‐lithium and subsequently coupled with 2‐bromo‐1,3,‐ditert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazaborole ( 3 ) to afford bis(1,3‐ditert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazaborol‐2‐yl)acetylene ( 9 ) as thermolabile colorless crystals. Analogously coupling of the lithiated species with 6 or with 2‐bromo‐1,3‐ditert‐butyl‐1,3,2‐diazaborolidine ( 11 ) gave the unsymmetrically substituted acetylenes 10 or 12 , respectively, as colorless solids. Compounds 4 , 5 , 7 – 10 and 12 are characterized by elemental analyses and spectroscopy (IR, ¹H‐, ¹¹B{¹H}, ¹³C{¹H}‐NMR, MS). The molecular structures of 5 , 8 and 9 were elucidated by X‐ray diffraction analyses.     

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).     

Na3OsH7 – Synthese,Struktur und magnetische Eigenschaften,sowie Untersuchungen zur Existenz einer analogen Rutheniumverbindung

Na₃OsH₇ – Synthesis, Structure, and Magnetic Properties as well as Investigations on the Existence of the Analogous Ruthenium Compound Na₃OsH₇ was synthesized by the reaction of sodium hydride with osmium powder under a hydrogen pressure of more than 1500 bar at 870 K. X‐ray investigations on powdered samples and elastic neutron diffraction experiments on the deuterated compound led to the atomic arrangement (space group: P4₂/mnm), which is characterized by isolated [OsD₇]‐anions. The coordination polyhedron formed by the seven deuterium ligands can be described as a distorted pentagonal bipyramide. Magnetic susceptibility measurements in the temperature range between 3.5 K and room temperature revealed a weak temperature independent paramagnetism. Quantum mechanical calculations confirm these facts and show in detail that the large value of the spin‐orbit coupling constant is responsible for the magnetic behaviour of the osmium (IV) compound. To synthesize the analogous ruthenium hydride it was necessary to increase the hydrogen pressure during the reaction up to 5000 bar. X‐ray investigations showed that Na₃RuH₇ crystallizes in an atomic arrangement isotypic to that of the osmium compound.     

Struktur und Eigenschaften des Methylpentafluorphosphatanions, [CH3PF5]—

Structure and Properties of the Methyltetrafluorophosphate Anion, [CH₃PF₅]^— Methyltetrafluorphosphorane reacts with the fluorides NaF, KF, CsF, and (CH₃)₄NF with formation of the corresponding methylpentafluorophosphates. In case of the K and Cs salts K[CH₃PF₅] · CH₃CN and Cs[CH₃PF₅] · CH₃CN, respectively, are formed using acetonitrile as solvent. The salts are characterized by NMR, IR and Raman spectroscopy. The vibrational frequencies are compared with ab initio calculated data (RHF/6‐31+G*). The RHF/6‐31+G* calculation yields for the almost octahedral anion bond distances of d(PF_eq) = 163.7 pm, d(PF_ax) = 162.0 pm, and d(PC) = 184.8 pm.