Showing papers on "Diborane published in 1975"
TL;DR: In this article, boron was diffused into the poly Si layers of 5·5 μm thickness with borsides and diborane as borside sources and the diffusion depth was found to be proportional to the square root of diffusion time.
Abstract: Boron was diffused into the poly Si layers of 5·5 μm thickness with boron nitride and diborane as boron sources. The diffusion depth was found to be proportional to the square root of diffusion time. The boron diffusion in the poly Si layers can be expressed in the well known complementary error function. The diffusion coefficient of boron in the poly Si layers is larger when diborane is used than when boron nitride is used as a boron source and is 10–50 times larger than that in the single crystal silicon substrates in the experimental range. The diffusion coefficients of boron at 1050°C in the single crystal silicon substrates with diborane as a boron source in the poly Si layers with boron nitride and diborane as boron sources are 8·80 × 10 −14 , 1·17 × 10 −12 and 1·95 × 10 −12 cm 2 /sec, respectively. The activation energies of the diffusion coefficients of boron in the above each case are 3·42, 2·39 and 2·51 eV, respectively.
41 citations
TL;DR: In this paper, the reduction of pyridine-3,5-dicarboxylates by sodium borohydride to give the corresponding 1,2 and 1,4-dihydropyridines has been investigated, and the compositions of the isomer mixtures produced in various solvents have been determined.
Abstract: The reduction of pyridine-3,5-dicarboxylates by sodium borohydride to give the corresponding 1,2- and 1,4-dihydropyridines has been investigated, and the compositions of the isomer mixtures produced in various solvents have been determined. New syntheses have been developed for 3,5-disubstituted 1,4-dihydropyridines involving reduction with sodium cyanoborohydride, and for 1,2-dihydropyridine-3,5-dicarboxylates involving reduction with diborane. Details of the previously reported catalytic hydrogenation of pyridines are given.
22 citations
TL;DR: In this paper, two methods for the reduction of aldonolactones to aldoses have been developed for use in small-scale syntheses, such as those of 13C-enriched sugars.
19 citations
TL;DR: In this article, the electronic structure of the diborane molecule was examined within a simple group function model and the group functions were taken to be a product of singly occupied non-orthogonal orbitals.
Abstract: The electronic structure of the diborane molecule is examined within a simple group function model. The group functions are taken to be a product of singly-occupied non-orthogonal orbitals. This model yields a molecular wavefunction which provides a simple interpretation while incorporating a substantial amount of chemically significant electron correlation. The resulting description makes possible a direct quantitative verification of the qualitative valence-shell electron-pair repulsion theory of directed valence.
18 citations
TL;DR: The 27Al−13C coupling constants in trimethylaluminum and its derivatives were obtained by line shape analyses of the unresolved broadened signals of the proton−decoupled 13C NMR spectra in a wide temperature range as mentioned in this paper.
Abstract: The 27Al–13C coupling constants in dimers of trimethylaluminum, dimethylaluminum chloride and bromide, and diethylaluminum chloride, and in the trimethylaluminum–diethylether complex were obtained by line shape analyses of the unresolved broadened signals of the proton‐decoupled 13C NMR spectra in a wide temperature range. There is a remarkable parallelism between 27Al–13C coupling constants in trimethylaluminum dimer and its derivatives and the 11B–1H coupling constants in diborane derivatives. This comes from the similarity in the electronic structure of the two types of electron deficient compounds, and can be accounted for in the framework of the Fermi contact mechanism for the spin coupling.
17 citations
TL;DR: In this article, several methods were explored for preparing certain 4,5-disubstituted-1,2,3-thiadiazoles, including the reaction of phenoxyacetyl chlorides with diazoacetylamides.
17 citations
TL;DR: In this paper, all-valence-electron Cl calculations have been carried out for diborane B 2 H 6 and its positive ion employing a rather large double-zeta AO basis including polarization functions in order to study the electronic spectrum of this system.
16 citations
TL;DR: Aryl organothallium compounds react with diborane in tetrahydrofuran solution to give intermediates which on oxidation or hydrolysis give good yields of phenols or arylboronic acids respectively.
Abstract: A wide range of aryl organothallium compounds react with diborane in tetrahydrofuran solution to give intermediates which on oxidation or hydrolysis give good yields of phenols or arylboronic acids respectively.
12 citations
TL;DR: The course of nearly four decades of research on the preparation and reactions of diborane and its derivatives is reviewed in this paper, where the authors present a review of the most relevant works.
10 citations
TL;DR: The titled compounds (1, 2) have been prepared from estrone by the new synthetic routes as discussed by the authors by introducing a hydroxyl group into the 15α-position, which was readily attained by hydroboration of the 14, 15-or 15, 16-double bond with diborane and subsequent oxidation of the organoborane with alkaline hydrogen peroxide.
Abstract: The titled compounds (1, 2) have been prepared from estrone by the new synthetic routes. Introduction of a hydroxyl group into the 15α-position was readily attained by hydroboration of the 14, 15-or 15, 16-double bond with diborane and subsequent oxidation of the organoborane with alkaline hydrogen peroxide. In the preparation of 1 the dimethyl-tert-butylsilyl function was conveniently employed for the purpose of protecting the 3, 17β-hydroxyl groups.
9 citations
Patent•
12 May 1975TL;DR: The 3-amino-substituted cephem esters are useful intermediates undergoing reduction with diborane to the corresponding 3H-3-cephem ester, or, alternatively, they are reacted with Grignard reagents, e.g., phenylmagnesium bromide to provide, for example, the 3-phenyl-3.
Abstract: 7-Amino-(or 7-acylamido)-3-(disubstituted-amino)-3-cephem-4-carboxylic acid esters are prepared with the corresponding 3-chloro-3-cephem ester or 3-alkyl-(or aryl)-sulfonyloxy-3-cephem esters and a secondary amine, e.g., diphenylmethyl 7-[2-(2-thienyl)acetamido] -3-morpholino-3-cephem-4-carboxylate is prepared with the corresponding 3-methyl-sulfonyloxy ester and morpholine. The 3-amino-substituted cephem esters are useful intermediates undergoing reduction with diborane to the corresponding 3H-3-cephem esters, or, alternatively, they are reacted with Grignard reagents, e.g., phenylmagnesium bromide to provide, for example, the 3-phenyl-3-cephem ester.
Patent•
16 Jul 1975
TL;DR: In this article, a method for the recycling of lithium borate to lithium borohydride which can be reacted with water to generate hydrogen for utilization as a fuel was proposed, where the boric acid and lithium chloride were converted to borhydride through a diborane intermediate to complete the recycle scheme.
Abstract: This invention provides a method for the recycling of lithium borate to lithium borohydride which can be reacted with water to generate hydrogen for utilization as a fuel. The lithium borate by-product of the hydrogen generation reaction is reacted with hydrogen chloride and water to produce boric acid and lithium chloride. The boric acid and lithium chloride are converted to lithium borohydride through a diborane intermediate to complete the recycle scheme.
TL;DR: In this article, a discussion on the structures of intermediate products is reported, and a discussion of the intermediate products of aliphatic tosylhydrazides is discussed. But they do not discuss the structure of intermediate product.
TL;DR: The He I and He II photoelectron (p.e.) spectra of the title compounds are reported in this paper, and the p.e. spectrum of pentaborane (9) shows marked differences from one previously reported.
Abstract: The He I and He II photoelectron (p.e.) spectra of the title compounds are reported. Ab initio SCF-MO calculations have been carried out on diborane, pentaborane(9) and tetraborane(10) using a double zeta basis of Slater-type orbitals. Assignment of the spectra is made with the aid of these calculations and by correlation with the spectrum of diborane. The p.e. spectrum of pentaborane (9) shows marked differences from one previously reported.
TL;DR: In this paper, three rnethoxypyrrole esters were reduced with diborane/tetrahydrofuran, lithium aluminum hydride, and some related reducing agents.
TL;DR: In this article, the ESR spectra were examined for diborane anion radicals, B2H6−, formed when dibarane adsorbed on several kinds of adsorbents was irradiated with γ-rays at 77 K or pre-irradiated with ǫ-ray at 77 k.
Abstract: The ESR spectra were examined for diborane anion radicals, B2H6−, formed when diborane adsorbed on several kinds of adsorbents was irradiated with γ-rays at 77 K or diborane adsorbed at 77 K on adsorbents pre-irradiated with γ-rays at 77 K. The radicals in the adsorbed state were compared with those in an argon matrix, previously reported.
Patent•
10 Jan 1975
TL;DR: In this article, boron trifluoride is used to reduce the carboxylic acid group and eliminates the need for the large excess of the borane complex normally required due to the competing formation of BORON-nitrogen compounds.
Abstract: Organic compounds containing both an amino group and a carboxylic acid group are reduced when treated with boron trifluoride followed by diborane, a borane-ether or borane-organic sulfide complex. The presence of the boron trifluoride is responsible for an increase in the rate of reduction of the carboxylic acid group and eliminates the need for the large excess of the borane complex normally required due to the competing formation of boron-nitrogen compounds. Hydrolysis of the reaction mixture provides a useful and convenient method for separating the corresponding amino alcohol.
TL;DR: In this article, the ESR-Spektren von B2H6(-)-Radikalen werden untersucht, die entstehen, wenn B 2H6 an bestimmte Adsorbenzien adsorbiert ist und with γ-Strahlen bei 77 K bestrahlt wird oder B 2 H6 bei 66 K bestraht wird.
Abstract: Die ESR-Spektren von B2H6(-)-Radikalen werden untersucht, die entstehen, wenn B2H6 an bestimmte Adsorbenzien adsorbiert ist und mit γ-Strahlen bei 77 K bestrahlt wird oder B2H6 bei 77 K an bereits mit γ-Strahlung bestrahlte Adsorbenzien adsorbiert wird.
TL;DR: According to the data of the IR spectra, the nature of the bond of the BH4 groups to aluminum in the anion [(ClO4)Al (BH4)4] is the same as that of the perchlorato group is monodentately bonded to the Al atom as discussed by the authors.
Abstract: 1.
Complex compounds with the composition R4N[(ClO4)Al (BH4)3], where R = CH3, C2H5, and C4H9, were obtained by the direct interaction of aluminum borohydride with tetraalkylammonium perchlorate.
2.
According to the data of the IR spectra, the nature of the bond of the BH4 groups to aluminum in the anion [(ClO4)Al (BH4)4] is the same as in the anion Al (BH4) 4 − . The perchlorato group is monodentately bonded to the Al atom, as in the anion [Al(ClO4)6—.
3.
The complex compounds R4N (ClO4)Al(BH4)3] are stable at ∼20°, but are sensitive to mechanical influence. The tetrabutylammonium complex decomposes slowly in the interval 100–200° with the liberation of diborane and hydrogen.
TL;DR: In this article, complexes with the composition (R4N)2B12H12· 2Al (BH4)3 were obtained by the interaction of aluminum borohydride with R4N2B 12H12.
Abstract: 1.
Complexes with the composition (R4N)2B12H12· 2Al (BH4)3were obtained by the interaction of aluminum borohydride with (R4N)2B12H12. The compounds were characterized by the values of the density and IR spectra.
2.
When the complexes were heated to ∼60° or treated with hydrocarbons under vacuum, there was an elimination of Al(BH4)3 with an admixture of diborane and hydrogen.
TL;DR: The ratio of the dissolved diborane and borohydride molecules corresponds to the formula MBH4 ·xBH3, where x ≈ 2.1.
Abstract: 1.
Diborane is absorbed by suspensions of the borohydrides of potassium, rubidium, and cesium in diglyme, with their simultaneous transition into solution. The solubility of the MBH4 increases in the order K to Cs. The ratio of the dissolved diborane and borohydride molecules corresponds to the formula MBH4 ·xBH3, where x ≈ 2.
2.
The borohydrides separate from solution when precipitated with diethyl ether.