Showing papers by "Alan H. Cowley published in 1991"
58 citations
TL;DR: The trimers [t-Bu 2 Ga(μ-EH 2 )] 3 (E=P, As) have been prepared via the reaction of t-Bu 3 Ga with EH 3 at low temperatures as discussed by the authors.
44 citations
TL;DR: The first isopropyl-substituted trimers of the type (Me 2 M(μ-E-i-Pr 2 )) 3 (1M=Ga, E=P; 2 M=In, E =P; 3 M=Ga and E=As) have been synthesized as mentioned in this paper.
42 citations
32 citations
TL;DR: In this article, the structure of t-Bu2GaCl with LiNHPh in toluene/diethylether (4 : 1) at −78°C gives the dimeric primary amido complex [t-bu2Ga(μ-NHPh)]2 (1) in 60% yield.
32 citations
26 citations
TL;DR: The reaction of [Ga(t-C 4 H 9 )Cl 2 ] 2 with the nido-carborane dianionic double salts Na + Li + [2-(SiMe 3 )-3-(R)-2,3-C 2 B 4 H 4 ] 2− (R=SiME 3, Me, H) in a molar ratio of 1:2 in THF was shown to yield closo-1-(t-H 9 )-1-Ga-2.
17 citations
TL;DR: In this paper, the interaction of the Na + (THF)Li + [2,3-(SiMe 3 ) 2 C 2 B 4 H 4 ] 2− double salt with (Me) 2 CHInI 2 in a molar ratio of 1:1 in dry THF produced the closo-indacarborane 1-[(Me 2 CH]-1-In III -2, 3-(SiME 3 )2 -2
17 citations
TL;DR: In this article, the reaction between the Na + (THF)Li + [2,3-(SiMe 3 ) 2 C 2 B 4 H 4 ] 2− double salt and 2,4,6-(t-Bu) 3 C 6 H 2 PCl 2 in a molar ratio of 1:1 in dry THF produced in 38% yield the previously unknown closo-phosphacarborane complex.
Abstract: The reaction between the Na + (THF)Li + [2,3-(SiMe 3 ) 2 C 2 B 4 H 4 ] 2− double salt and 2,4,6-(t-Bu) 3 C 6 H 2 PCl 2 in a molar ratio of 1:1 in dry THF produced in 38% yield the previously unknown closo-phosphacarborane complex, 1-[2,4,6-(t-Bu) 3 C 6 H 2 ]-1-P-2,3-(SiMe 3 ) 2 -2,3-C 2 B 4 H 4 (I) as an air-sensitive, white, crystalline solid. The new complex was characterized by 1 H, 11 B, 13 C, and 31 P NMR, IR, and mass spectroscopy. These spectroscopic data are consistent with the proposed pentagonal-bipyramidal structure, which contains 16 skeletal valence electrons
13 citations
12 citations
TL;DR: In this article, the chloride-bridged dimer (t-BuGaCl2)2 with Ar′P(H)Li (AR′ = 2,4,6-tBu3C6H2) affords the chloridebridged Dimer [t-buGa(Cl)P (H)Ar′]2 (1).
Abstract: The reaction of (t-BuGaCl2)2 with Ar′P(H)Li (AR′ = 2,4,6-t-Bu3C6H2) affords the chloride-bridged dimer [t-BuGa(Cl)P(H)Ar′]2 (1). The structure of 1 has been established by X-ray crystallography. Compound 1, C44H78Cl2Ga2P2, crystallizes in the monoclinic space group P21/n with Z = 2, a = 10.468(1), b = 14.967(1), c = 16.182(2) A, and A = 94.48(1)β. The reaction of 1 with t-BuLi is described.
TL;DR: In this paper, the structure of the triclinic octahedron was studied by variable temperature 13C NMR spectroscopy and activation enthalpies (kcal mol−1): 10.3±0.1, 0.21 ± 0.5, −2.5 and −1.9± 0.2, respectively.
TL;DR: In this paper, the interaction of the Na + (THF)Li + [2,3-(SiMe 3 ) 2 C 2 B 4 H 4 ] 2− double salt with (Me) 2 CHInI 2 in a molar ratio of 1:1 in dry THF produced the closo-indacarborane 1-[(Me 2 CH]-1-In III -2, 3-(SiME 3 )2 -2
Abstract: Interaction of the Na + (THF)Li + [2,3-(SiMe 3 ) 2 C 2 B 4 H 4 ] 2− double salt with (Me) 2 CHInI 2 in a molar ratio of 1:1 in dry THF produced the closo-indacarborane 1-[(Me) 2 CH]-1-In III -2,3-(SiMe 3 ) 2 -2,3-C 2 B 4 H 4 (1) as a white, air-sensitive, and low-melting crystalline solid in 39% yield. Complex 1 was characterized by 1 H, 11 B, and 13 C NMR spectra, by mass and IR spectra, and also by X-ray crystallography
01 Jan 1991
TL;DR: In this paper, a project was undertaken to see if CaF2 films could be grown by chemical methods, where the material of interest is produced by a chemical reaction on the substrate surface by one or more precursor molecules(s), which are delivered to the substrate in the gas phase.
Abstract: : There is currently a great deal of interest in insulator on semiconductor layer constructions in the electronics community. Calcium fluoride is electronically insulating and lattice matched to both silicon and gallium arsenide, which makes it an ideal insulator for these materials. Also, CaF2 is being used as an insulator with thin films of the high temperature superconducting materials. While there has been a great deal of work in the deposition of CaF2 films by physical techniques, such as molecular beam epitaxy (MBE), this technique is not considered to be viable for large scale production techniques due to the expensive and sophisticated high vacuum equipment involved. Another problem with MBE of CaF2 is that high substrate temperatures (greater than 500 C) seem to be required for good quality films. Due to the differences in thermal expansion between CaF2 and silicon or gallium arsenide, these films tend to crack when cooled to ambient temperature. Therefore, a project was undertaken to see if CaF2 films could be grown by chemical methods. The most useful of these is the Chemical Vapor Deposition (CVD) method, where the material of interest is produced by a chemical reaction on the substrate surface by one or more precursor molecule(s), which are delivered to the substrate in the gas phase. For a binary material, such as CaF2, there are two CVD growth methods. In a dual source method, two precursors are used, each of which contains one of the elements in the film material. In the single source technique, a precursor molecule which contains both elements that comprise the film material is used. This report will describe work in which each approach was tried.
TL;DR: In this article, the chloride-bridged dimer (t-BuGaCl2)2 with Ar′P(H)Li (AR′ = 2,4,6-tBu3C6H2) affords the chloridebridged Dimer [t-buGa(Cl)P (H)Ar′]2 (1).
Abstract: The reaction of (t-BuGaCl2)2 with Ar′P(H)Li (AR′ = 2,4,6-t-Bu3C6H2) affords the chloride-bridged dimer [t-BuGa(Cl)P(H)Ar′]2 (1). The structure of 1 has been established by X-ray crystallography. Compound 1, C44H78Cl2Ga2P2, crystallizes in the monoclinic space group P21/n with Z = 2, a = 10.468(1), b = 14.967(1), c = 16.182(2) A, and A = 94.48(1)β. The reaction of 1 with t-BuLi is described.