Intramolekular schwefelstabilisierte Aluminium‐ und Galliumalkyle

Intramolecularly Sulfur stabilized Aluminum and Gallium Alkyl Derivatives The intramolecularly sulfur stabilized organoaluminum and organogallium compounds Me₂Al(CH₂)₃SEt ( 1 ), Me₂Ga(CH₂)₃SEt ( 2 ), MeClAl(CH₂)₃SEt ( 3 ), MeClGa(CH₂)₃SEt ( 4 ), Cl₂Al(CH₂)₃SEt ( 5 ), and Cl₂Ga(CH₂)₃SEt ( 6 ) are synthesized from Me₂MCl, MeMCl₂, and MCl₃ (M = Al, Ga), respectively, and ClMg(CH₂)₃SEt. The reaction of 5 and of 6 with BrMg(CH₂)₅MgBr yields (CH₂)₅Al(CH₂)₃SEt ( 7 ) and (CH₂)₅Ga(CH₂)₃SEt ( 8 ), respectively. AlCl₃ and GaCl₃ react with two as well as three equivalents of ClMg(CH₂)₃SEt forming ClAl[(CH₂)₃SEt]₂ ( 9 ) and ClGa[(CH₂)₃SEt]₂ ( 10 ) as well as Al[(CH₂)₃SEt]₃ ( 11 ) and Ga[(CH₂)₃SEt]₃ ( 12 ), respectively. The compounds were characterized by elemental analyses, mass spectroscopy, ¹H, ¹³C, and ²⁷Al NMR investigations as well as 6 by single crystal X‐ray structure analysis.     

Die Kristallstruktur von [Li · 11/3 H2O · C7H8][{(CH3)3Si}3C–GaI3], ein stabiles Hydrat des Lithium‐Tris(trimethylsilyl)methyl‐triiodogallats

The Crystal Structure of [Li · 1¹/₃ H₂O · C₇H₈][{(CH₃)₃Si}₃C–GaI₃], a Stable Hydrate of Lithium Tris(trimethylsilyl)methyl Triiodogallate Water‐free Li[Tsi–GaI₃], prepared from gallium triiodide and base‐free Tsi–Li (Tsi = –C(SiMe₃)₃) in toluene, which has been recrystallized several times from humid toluene, c‐hexane, benzene and toluene again gives the water‐containing title compound. According to the X‐ray structure determination this product crystallizes in the monoclinic space group P2₁/c and consists of three‐membered units of [Tsi–GaI₃]^–‐anions forming an asymmetric triangle and a related chain of three Li cations, four fold but dissimilar coordinated by the oxygen atoms of 4 water molecules, the iodligands of different anions and a h²‐bonded toluene molecule, respectively.     

Crystal Structure Determination of Tetrabarium‐digalliumoxide,Ba4Ga2O7

Single crystals of a new barium oxogallate were obtained by growth from a melt at 1500 °C. The compound is monoclinic, with cell parameters a = 17.7447(10) Å, b = 10.6719(5) Å, c = 7.2828(5) Å, β = 98.962(7)°, V = 1362.3(2) ų. The diffraction pattern shows systematic absences corresponding to the space group P12₁/c1. The structure was solved by direct methods followed by Fourier syntheses, and refined using a single crystal diffraction data set (R1 = 0.032 for 2173 reflections with I > 2σ(I)). The chemical composition derived from structure solution is Ba₄Ga₂O₇, with a unit cell content of Z = 6. Main building units of the structure are GaO₄ tetrahedra sharing one oxygen atom to form Ga₂O₇ groups. The Ga–O–Ga bridging angle of one of the two symmetrically independent groups is linear by symmetry. The dimers are crosslinked by barium cations coordinated by six to eight oxygen ligands.     

Tris(tris(trimethylsilyl)silyl)gallium,Ga{Si(Si(CH3)3)3}3

The title compound has been prepared in good yield by the reaction of gallium trichloride with base‐free hypersilyl lithium (Li–Si(SiMe₃)₃, Me = CH₃) in a 1 : 3 molar ratio. Ga(Si(SiMe₃)₃)₃ is monomeric in solution and in the solid state. The compound has been characterized with NMR, IR and Raman techniques as well as by an X‐ray structure determination (planar GaSi₃‐skeleton, monoclinic space group P2₁/c, Z = 4, d(Ga–Si) = 249,8 ± 0,2 pm).     

Der Chemische Transport von Kupfer/Gallium‐ und Silber/Gallium‐Phasen

Chemical Vapor Transport of Intermetallic Systems. 10. Chemical Transport of Copper/Gallium and Silver/Gallium Phases The solid solution of gallium in copper and the ζ‐ and the γ‐phase can be prepared by CVT‐methods using iodine as transport agent. The solid solution of gallium in silver and the ζ‐phase and the ζ′‐phase can also prepared by CVT‐methods. Thermodynamic calculations allow to understand why these phases can be prepared by this manner.     

Homogeneous alignment of liquid crystals on low-temperature solution-derived gallium oxide films via IB irradiation method

In this paper, solution-derived gallium oxide (GaO) films are fabricated for the homogeneous alignment of liquid crystals (LCs) after an ion-beam (IB) irradiation process. GaO thin films are prepared under a variety of temperatures and different IB irradiation intensities, and the physicochemical performances of the fabricated GaO thin films are analysed using a UV-vis spectrometer, an atomic force microscope, and X-ray photoelectron spectroscopy. A higher transmittance of 85.40% from GaO thin film is obtained compared with that of polyimide (PI) film (83.52%), which indicates the feasibility for a GaO thin layer to substitute for a conventional PI layer as an alignment layer. LCs are found to align on the GaO thin film after pre-baking at 100°C and homogeneous and uniform low-IB intensity irradiation. We also determined the electro-optical (EO) characteristics of the twisted nematic (TN) cells fabricated with GaO thin layers and found them to be similar to those of cells fabricated with PI layers. Overall, GaO films achieved via the IB irradiation method are promising LC alignment layers due to the method’s low-temperature solution-derived process.