25 research outputs found
(2,4,6-Trimethylphenyl)boronic acid–triphenylphosphine oxide (1/1)
In the crystal structure of the title compound, C9H13BO2·C18H15OP, there are O—H⋯O hydrogen bonds between the O atom of triphenylphosphine oxide and one hydroxy group of the boronic acid. Boronic acid molecules form inversion-related hydrogen-bonded dimers in an R
2
2(8) motif. The structure is consolidated by intermolecular C—H⋯O bonds and C—H⋯π interactions
Разработка и исследования ионного Br - диода
Объектом исследования является ионный Br–диод с внешним магнитным полем.
Целью работы является разработка конструкции ионного Br–диода и проведение на нем исследовании по генерации мощных ионных пучков различного массового состава и фокусировки ионного пучка, для повышения эффективности работы ионного диода и ресурса работы анодного покрытия.
В процессе исследования проводились расчеты по определению размеров и конструкции ионного Br-диода, параметров магнитного поля, создаваемого внешним источником питания. По разработанному Br-ионному диоду проводились экспериментальные исследования различных эмиссионных покрытий анода, а также опыты по улучшению фокусировки ионного пучка.The object of investigation is an ion Br-diode with an external magnetic field.
The aim of the work is to develop the design of the ion Br-diode and to carry out research on the generation of powerful ion beams of various mass composition and focusing of the ion beam, in order to increase the efficiency of the ion diode and the life of the anode coating.
During the research, calculations were made to determine the size and design of the ion Br-diode, the parameters of the magnetic field created by an external power source. Based on the developed Br-ion diode, experimental studies of various emission coatings of the anode, as well as experiments to improve the focusing of the ion beam, were carried out
Bis[3-(dihydroxyboryl)anilinium] sulfate
In the title compound, 2C6H9BNO2
+·SO4
2−, the dihydroxyboryl group of one of the two independent boronic acid molecules participates in (B)O—H⋯OB and N—H⋯OB hydrogen bonds, while the second is involved mainly in the formation of the charge-assisted heterodimeric synthon –B(OH)2⋯−O2SO2
−. These aggregates are further connected through N—H⋯Osulfate interactions, forming a complex three-dimensional hydrogen-bonded network
A mechanistic proposal for the protodeboronation of neat boronic acids: boronic acid mediated reaction in the solid state.
A combined experimental and computational study suggests that a reduction in the entropy of activation in the solid state can lead to the protodeboronation of boronic acids
Synthese, Charakterisierung und Untersuchungen zum Reaktionsverhalten von Boraziden und Borylnitrenen
Wir konnten zeigen, dass bestimmte photochemisch erzeugte Borylnitrene eine hohe Tendenz zeigen in die starken C-H-Bindungen von Alkanen R´H - inklusive Methan - zu insertieren. Die gebildeten Aminoborane des Typs lassen sich dann im Anschluss bequem unter Spaltung der BN-Einheit in nützliche organische Verbindungen wie Amine und Amide abbauen
Crystal structure of (2′,3,6′-trichlorobiphenyl-2-yl)boronic acid tetrahydrofuran monosolvate
C–H Bond Amination by Photochemically Generated Transient Borylnitrenes at Room Temperature: A Combined Experimental and Theoretical Investigation of the Insertion Mechanism and Influence of Substituents
A number of azidoboranes having substitution patterns
that are
derived from catechol (<b>3</b>), pinacol (<b>4a</b>),
1,2-diaminoethane (<b>4b</b>,<b>c</b>), 1,2-ethanedithiol
(<b>4d</b>), and 1,2,4,5-tetrahydroxybenzene as well as acyclic
dialkoxy species (<b>5</b><b></b>) were synthesized and,
in the case of <b>4c</b> (<i>N</i>,<i>N</i>′-ditosyl-2-azido-1,3,2-diazaborolane), also structurally
characterized. The azidoboranes were photolyzed in cyclohexane solvent
in order to investigate the tendency of the generated borylnitrenes
to undergo intermolecular C–H insertion reactions. The yields
of intermolecular insertion products ranged from very good (<b>4a</b>) to vanishingly small, depending on the substitution of
the azidoborane. For a number of borylnitrenes the zero-field splitting
parameter <i>D</i> was measured in organic glasses at 4
K. The small primary kinetic isotope effect (<i>k</i><sub>H</sub>/<i>k</i><sub>D</sub> = 1.35) measured for <b>4a</b> in mixtures of [H<sub>12</sub>]cyclohexane and [D<sub>12</sub>]cyclohexane suggests that the insertion reaction is concerted and
involves the singlet state of the borylnitrene. Computations at the
CBS-QB3 and CCSD(T)/TZ2P levels of theory show that the relative energies
of singlet and triplet states of a wide variety of borylnitrenes and
even their nature as minima or saddle points depend strongly on the
substituents. Photolysis of the most reactive azidoborane, <b>4a</b>, in methane in a flow reactor at atmospheric pressure produces an
intermolecular insertion product in low yields, in agreement with
the expectation of intersystem crossing to the less reactive triplet
state of the borylnitrene
Mixed Stacked Charge-Transfer π-Organic Materials Based on Anthracenyl Boronic Acid
Anthracenyl boronic acid derivatives are used for the first time as hydrogen-bond and π-donors to obtain a series of novel 1:1 mixed stacked π-organic materials with interesting structural, UV/Vis reflectance and emission properties by reaction with quinones in both solution and the solid. The underlying principles, which have led to hetero-assembly, could be applied to construct a potentially large variety of mixed stacked π-organic solid-state materials for technological applications