Cyclosiloxanes Containing a Gallium Atom as Ring Member from the Reaction oftert-Butoxygallane with Di- and Trisiloxanediols

2002 ◽  
Vol 21 (2) ◽  
pp. 380-388 ◽  
Author(s):  
Michael Veith ◽  
Heidi Vogelgesang ◽  
Volker Huch
Keyword(s):  
Gallium Atom

Model of the Jahn-Teller Complex Formed in GaAs by a Gallium Vacancy and a Donor Substituting for a Gallium Atom*

1996 ◽  
Vol 1 (1) ◽  
pp. 209-215
Author(s):  
N. S. Averkiev ◽  
A. A. Gutkin ◽  
S. Yu. Il’inskii ◽  
M. A. Reshchikov ◽  
V. E. Sedov
Keyword(s):  
Gallium Atom ◽  
Gallium Vacancy ◽  
Jahn Teller

scholarly journals Darstellung, Struktur und einige Reaktionen von Tris(dimethylamino)gallan / Preparation, Structure and Some Reactions of Trisdimethylaminogallane

1975 ◽  
Vol 30 (9-10) ◽  
pp. 681-687 ◽  
Author(s):  
H. Nöth ◽  
P. Konrad
Keyword(s):  
Steric Hindrance ◽  
Nmr Spectra ◽  
Gallium Atom ◽  
H Nmr

The aminogallanes Ga[N(CH3)2]3 (1), ClGa[N(CH3)2]2 (2) and Ga[N(Si(CH3)3)2]3 (3) are prepared by reacting GaCl3 with LiN(CH3)2 and NaN[Si(CH3)3]2, respectively. Excess LiN(CH3)2 leads to LiGa[N(CH3)4] which reacts with GaCl3 to yield 1. CS2 inserts into all Ga—N bonds of 1 yielding monomeric Ga[S2CN(CH3)3)2]3 (4).1 dimerizes via dimethylamino bridges. In contrast, 1H. NMR spectra indicate group exchange for dimeric 2. Assoziation of 3 is prevented due to steric hindrance. The gallium atom in 4 exhibits hexacoordination, and there is evidence for the binding of the (CH3)2NCS2 groups through S atoms only.

Crystal and molecular structure of bis[methyltris(1-pyrazolyl)gallato]nickel(II)

1979 ◽  
Vol 57 (14) ◽  
pp. 1823-1825 ◽  
Author(s):  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Nickel Atom ◽  
Exact Formula ◽  
Coordination Geometry ◽  
Tetrahedral Coordination ◽  
Gallium Atom ◽  
Full Matrix ◽  
Distorted Tetrahedral Coordination

Crystals of bis[methyltris(1-pyrazolyl)gallato]nickel(II) are rhombohedral, a = 9.6670(5), c = 23.893(1) Å, Z = 3, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.030 and Rw = 0.035 for 925 reflections with I ≥ 3σ (I). The crystal structure consists of well separated molecules of [MeGa-(N2C3H3)3]2Ni having exact [Formula: see text] (S6) symmetry and approximate D3d symmetry. The coordination geometry about the nickel atom is octahedral with Ni—N = 2.109(2) Å, N—Ni—N = 90.65(6) and 89.35(6)°. The gallium atom has distorted tetrahedral coordination geometry with Ga—N = 1.939(2), Ga—C = 1.940(4) Å, N—Ga—N = 99.55(6), and N—Ga—C = 118.16(5)°.

Synthesis, characterization, and crystal and molecular structures of the coordination compounds, [Me2Ga•O(C5H3N)CH2NMe2] and [Me2Ga•O(C9H6N)]2

1987 ◽  
Vol 65 (4) ◽  
pp. 782-788 ◽  
Author(s):  
Emmanuel C. Onyiriuka ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Heavy Atom ◽  
Amino Nitrogen ◽  
Molecular Structures ◽  
Geometrical Parameters ◽  
Planar System ◽  
Gallium Atom ◽  
Space Group ◽  
Trigonal Bipyramidal ◽  
Distorted Trigonal Bipyramidal Coordination ◽  
Centrosymmetric Dimers

Crystals of (2-dimethylaminomethyl-3-pyridolato)dimethylgallium are monoclinic, a = 13.443(3), b = 6.7563(3), c = 13.046(2) Å, β = 100.38(1)°, Z = 4, space group I2/m, and those of bis[(8-quinolinolato)dimethylgallium] are monoclinic, a = 9.7340(4), b = 12.7135(5), c = 9.6843(4) Å, β = 117.014(3)°, Z = 2, space group P21/c. Both structures were solved by conventional heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.044 and 0.032 for 1485 and 1567 reflections with I ≥ 3σ(I), respectively. The structure of [Me2Ga•O(C5H3N)CH2NMe2] consists of discrete monomeric molecules which contain tetrahedrally coordinated gallium atoms. The bidentate anionic 2-dimethylaminomethyl-3-pyridolate ligand coordinates Ga via the oxygen and amino nitrogen atoms (Ga—O = 1.892(3), Ga—N = 2.127(4), Ga—C = 1.950(5) and 1.939(6) Å). The structure of [Me2Ga•O(C9H6N)]2 consists of centrosymmetric dimers which contain a nearly planar system of seven fused rings. The Ga atoms are five-coordinate, having distorted trigonal bipyramidal coordination geometry. The dimerization occurs via the formation of a central, planar, four-membered (Ga—O)2 ring in which each asymmetrically bridging oxygen atom occupies an equatorial coordination site on one gallium atom and an axial site on the other. Important geometrical parameters for [Me2Ga•O(C9H6N)]2 are Ga—O(eq) = 1.937(3), Ga—O(ax) = 2.297(3), Ga—N(ax) = 2.211(3), Ga—C(eq) = 1.948(6) and 1.945(5) Å, O(ax)—Ga—N(ax) = 149.7(1)°.

scholarly journals High Resolution and Solid State NMR Investigations of Subvalent Gallium Compounds

1986 ◽  
Vol 41 (1-2) ◽  
pp. 315-318 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Theodore Zafiropoulos ◽  
Wolfgang Bublak ◽  
Paul Burkert ◽  
Frank H. Köhler
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Gallium Atom ◽  
Line Shapes ◽  
Quadrupole Coupling ◽  
Structure Determinations ◽  
Constant E ◽  
Gallium Compounds

The 71Ga NMR spectra of Ga[GaX4] melts and of solutions in benzene and other hydrocarbons show discrete sharp GaI and broad GaIII resonances. In the light of recent structure determinations, the solution GaI signals must be attributed to bis(arene)Ga+ complexes in which the gallium atom is η6-bonded to the hydrocarbons. The low line widths and strong high field shifts are attributed to an almost spherical shielding of the metal nucleus by the 4 s2 electrons. Solid state 69Ga and 71Ga NMR spectra of Ga[GaCl4] crystalline powder show only Ga1 resonances. While the 71GaI line is rather narrow, the 69GaI line has a complex fine structure. Consistent with the crystal structure of Ga[GaCl4], the Ga1 ion is calculated to have a very low quadrupole coupling constant e2q Q/h = 1.7 ± 0.1 MHz and an asymmetry parameter η = 0.44. Experimental and simulated line shapes (using literature models) are in satisfactory agreement, implying that the 69Ga signal splitting is due to second order quadrupolar effects for the central m = + 1/2 ⇋ - 1/2 transition. The analogous splitting of the 71Ga NMR line is too small to be detected.

Ternary Gallides REMgGa (RE = Y, La, Pr, Nd, Sm–Tm, Lu) – Synthesis and Crystal Chemistry

2003 ◽  
Vol 58 (9) ◽  
pp. 827-831 ◽  
Author(s):  
Rainer Kraft ◽  
Martin Valldor ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Cell Volume ◽  
Coordination Number ◽  
High Frequency ◽  
Three Dimensional ◽  
Gallium Atom ◽  
X Ray ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

The title compounds have been synthesized by reacting the elements in sealed niobium or tantalum tubes in a high-frequency furnace. They crystallize with the hexagonal ZrNiAl type structure, space group P62m. All gallides have been characterized through their X-ray powder diffractogram. The cell volume decreases from the lanthanum to the lutetium compound as expected from the lanthanoid contraction. The structures of LaMgGa, PrMgGa, NdMgGa, SmMgGa and TmMgGa have been refined from single crystal diffractometer data. The structures contain two crystallographically independent gallium sites which both have a trigonal prismatic coordination: Ga1 by six RE and Ga2 by six Mg atoms. These trigonal prisms are capped on the rectangular sites by three Mg (RE) atoms, leading to coordination number 9 for each gallium atom. Together, the gallium and magnesium atoms form a three-dimensional [MgGa] network in which the rare earth atoms fill distorted hexagonal channels. Within the network the magnesium atoms have short Mg-Mg contacts, i. e. 312 pm in SmMgGa. The Mg-Ga distances in that gallide range from 284 to 287 pm. Bonding in the network is thus governed by strong Mg-Ga and Mg-Mg bonding. EuMgGa crystallizes with the orthorhombic TiNiSi type: Pnma, a = 783.1(2), b = 472.8(1), c = 829.8(2) pm.

Deep levels related to gallium atom clusters in GaAs

2001 ◽  
Vol 35 (1) ◽  
pp. 86-90 ◽  
Author(s):  
S. N. Grinyaev ◽  
V. A. Chaldyshev
Keyword(s):  
Deep Levels ◽  
Gallium Atom ◽  
Atom Clusters

Reactions in Omcvd: Detection of Gas Phase Radicals In Gaas Deposition Under Single Gas-Surface Collision Conditions

1987 ◽  
Vol 101 ◽  
Author(s):  
D.W. Squire ◽  
C.S. Dulcey ◽  
M.C. Lin
Keyword(s):  
Gas Phase ◽  
Ionization Mass ◽  
Laser Ionization ◽  
Methyl Radicals ◽  
Methyl Radical ◽  
Arrhenius Activation Energy ◽  
Gallium Atom ◽  
Surface Collision ◽  
Low Pressures ◽  
Radical Yield

ABSTRACTLaser ionization mass spectrometry has been used to study the deposition of gallium from trimethylgallium with and without AsH3. The apparent Arrhenius activation energy for the production of gas-phase methyl radicals from trimethylgallium is measured to be 28 ± 2 kcal/mol in the presence of AsH3, about the same value as measured in the absence of AsH3. At a substrate temperature of 1150 K where gallium desorption is substantial, addition of AsH3 is found to increase methyl radical yield but drastically decrease gallium atom desorption. A mechanism is presented to describe the deposition of GaAs at low pressures under single gas-surface collision conditions.

Sign in / Sign up

Export Citation Format

Share Document