353-42-4Relevant articles and documents
The Fourier transform infrared spectra of the complexes of boron trifluoride with dimethyl ether and dimethyl sulphide in cryogenic matrices
Nxumalo, Lawrence M.,Ford, Thomas A.
, p. 303 - 319 (2003)
The infrared spectra of boron trifluoride, co-condensed with dimethyl ether and with dimethyl sulphide in nitrogen and argon matrices at ca. 17 K, have been recorded. The spectra are consistent with the formation of 1:1 electron donor-acceptor molecular c
TEMPERATURE EFFECTS OF THE MOLECULAR STRUCTURE OF DIMETHYL ETHER-BORON TRIFLUORIDE AS STUDIED BY GAS-PHASE ELECTRON DIFFRACTION
Iijima, Kinya,Yamada, Tetsuji,Shibata, Shuzo
, p. 271 - 276 (1981)
The molecular structure of dimethyl ether-boron trifluoride (CH3)2O.BF3 has been studied at temperatures of 16, 30 and 70 deg C by gas-phase electron diffraction.The molecule exists in a staggered conformation with an O-B distance of 1.75 +/- 0.02 Angstroem, an angle between the O-B bond and the COC plane of 40 +/- 8 deg and an FBF angle 117 +/- 2 deg at each temperature.However, the F-B and C-O distances are found to decrease with increasing temperature, and appear to converge to the corresponding values of the component molecules.The temperature dependence of the B-F and C-O distances is surprisingly large, compared with those in other molecules.
RELAXATION KINETICS IN GASEOUS LEWIS ACID/BASE SYSTEMS: THE PROTOTYPE, (CH3)2O+BF3
Borchardt, D. B.,Saito, K.,Bauer, S. H.
, p. 375 - 382 (1990)
When a gaseous mixture of ether, boron trifluoride and their complex, at equilibrium (temperature range 290-335 K), is slightly perturbed by the imposition of a rapid temperature jump ca. 3 to 6 deg, the system relaxes to a new equilibrium.From the dependence of the measured relaxation time on the pressure of the reagents, the initial temperature and the pressure of a diluent gas (argon), we derived rate constants for the dissociation and association processes, based on published values of the equilibrium constant, Keq(T).The temperature dependence of the dissociation rate constant leads to an activation energy (2nd order regime), for comparison with the O-B (donor-acceptor) bond dissociation energy.
Monohydrater cefotiam hydrochloride compound and pharmaceutical composition thereof
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Paragraph 0039; 0042; 0051; 0060, (2019/01/23)
The invention discloses a monohydrate cefotiam hydrochloride compound and a preparing method thereof. One mole of cefotiam hydrochloride contains one mole of water, and an x-ray diffraction spectrogram of the compound has characteristic peaks at the positions with the diffraction angles 2theta of 14.82-15.22 degrees, 29.92-30.32 degrees, 31.48-31.88 degrees, 35.01-35.41 degrees and 37.79-38.19 degrees. 7-amino-cephalosporanic acid (7ACA) serving as a starting material is condensed with 1-(2-dimethylaminoethyl)-5-thiotetrazole under the catalytic effect of organic solvents dimethyl carbonate boron trifluoride and the like to prepare an intermediate at a C-3 site; then 2-(2-aminothiazol-4-yl) acetic acid hydrochloride reacts with methylene chloride and concentrated hydrochloric acid gas to prepare acyl chloride at a 7 site, and the one-water cefotiam hydrochloride compound is synthesized. The operation is simple and environmentally friendly, the reactants are easily obtained, the reaction conditions are mild, and the yield is high. The one-water cefotiam hydrochloride compound has low hygroscopicity and impurity content, good fluidity and thermodynamic stability and wider applicationprospects.