نتایج جستجو برای: boron compounds
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Stable pentaborane, B&H9, is one of the boron hydrides, a short, comparatively little studied series of extraordinary compounds for which a satisfactory elementary valence theory is lacking. In 1947 we decided to undertake new electron diffraction studies of the molecular structures. The early diffraction work and most of the theoretical discussion had been too much influenced (it now seems) by...
A directed cross-aldol reaction of silyl enol ethers with carbonyl compounds, such as aldehydes and ketones, promoted by a Lewis acid, a reaction which is now widely known as the Mukaiyama aldol reaction. It was first reported in 1973, and this year marks the 40th anniversary. The directed cross-aldol reactions mediated by boron enolates and tin(II) enolates also emerged from the Mukaiyama labo...
1- in a search directed to the reaction of compound)23(the cycloaddition reaction of 1,3- diphenylisobenzofurane)14(with p-benzoquinone)19(,followed by addition of cyclopentadiene was carried out.the specific spacial stracture of its ir,nmr,mass spectra. 2- in another attempt the kinetic stability and behavior of compounds)20(and)23(was studied.the main subject of this study was the highly reve...
The results of a solid-state (11)B NMR study of a series of 10 boronic acids and boronic esters with aromatic substituents are reported. Boron-11 electric field gradient (EFG) and chemical shift (CS) tensors obtained from analyses of spectra acquired in magnetic fields of 9.4 and 21.1 T are demonstrated to be useful for gaining insight into the molecular and electronic structure about the boron...
12 The decrease in energy was not found to increase instrumental stray light significantly. The stray light characteristics of the instrument are discussed elsewhere., 3Jones, R. N., J. Am. Chem. Soc., 74, 2681 (1952). 14 A similar apparatus is described by J. Cunningham and F. C. Tompkins, Proc. Roy. Soc., A251, 27 (1959). 51 Simpson, W. T., and D. L. Peterson, J. Chem. Phys., 26, 588 (1957). ...
Standardization of the Pharmaceutical Substance of the Silicon-zinc-boron-containing Glycerohydrogel
Introduction. Silicon-zinc-boron-containing glycerohydrogel substance is considered as a pharmaceutical for the new drugs creation with antimicrobial action local, external and intravaginal use. Standardization validation of methods determining quality parameters corresponding substances one stages introducing pharmacologically active compounds into practice. Aim. Determine silicon-zinc-boron-c...
Boron compounds are used as wood preservatives as they are both fungicide and insecticide, relatively inexpensive and environmentally acceptable. Nevertheless, in the field of wood protection, borates are only used for indoor non-exposed applications or in association with other biocides, due to their main disadvantage of being readily leachable from treated wood. To overcome this problem, bori...
Herein we present, an exhaustive docking analysis considering the case of autotaxin (ATX). HA155, a small molecule inhibitor of ATX, is co-crystallized. In order to further extract conclusions on the nature of the bond formed between the ligands and the amino acid residues of the active site, density functional theory (DFT) calculations were undertaken. However, docking does not provide reprodu...
UB, 13C, 14N, 15N NM R is used to study methylaminodiphenylborane (1). Compound 1 can be regarded as a model compound for studying BN(pp)jr-, B C (pp)7r interactions, for determining the barrier to rotation about the B —N bond and for the application of natural abundance 15N NM R to boron-nitrogen chemistry. The 13C NM R of 1 shows a large splitting of the uC (para) resonances (in contrast to r...
The crystal structure of Mg(2)B(25), dimagnesium penta-eicosa-boride, was reexamined from single-crystal X-ray diffraction data. The structural model previously reported on the basis of powder X-ray diffraction data [Giunchi et al. (2006 ▶). Solid State Sci.8, 1202-1208] has been confirmed, although a much higher precision refinement was achieved, leading to much smaller standard uncertainties ...
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