Antofloxacin free base is prepared from antofloxacin hydrochloride by removing hydrogen chloride. Its crystal is obtained by slow evaporation of an acetonitrile-methanol mixed solution. Single-crystal X-ray diffractio...Antofloxacin free base is prepared from antofloxacin hydrochloride by removing hydrogen chloride. Its crystal is obtained by slow evaporation of an acetonitrile-methanol mixed solution. Single-crystal X-ray diffraction reveals that the crystallography belongs to a triclinic PI space group with cell parameters： a = 0. 663 07（13） nm, b = 0. 898 39（18） nm, c = 1. 569 0（3） nm, α = 75.12（3）°,β = 87.92（3）°, γ = 77.57 （3）°. Antofloxacin shows no fluorescence in solution, but the crystalline state emits strong green light at 510 nm under the excitation of 360 nm, indicating a fluorescence enhancement induced by aggregation. It demonstrates that intermolecular packing and interaction in the crystal lead to the improved fluorescence quantum yield. These results provide important intbrmation for the further exploration of the structure-activity relationship of antofloxacin and the development of new drugs.展开更多
The title compound 2-(4-fluorophenylamino)-2-thiomethyl acetophe-none (C15H14FNOS, M. = 275. 34 ) was synthesized by the reaction of 2-hydroxy-2-thiomethyl acetohenone (abenzoylhemithioacetal ) with 4-fluoroaniline. T...The title compound 2-(4-fluorophenylamino)-2-thiomethyl acetophe-none (C15H14FNOS, M. = 275. 34 ) was synthesized by the reaction of 2-hydroxy-2-thiomethyl acetohenone (abenzoylhemithioacetal ) with 4-fluoroaniline. The crystal ismonoclinic, space group P21/n. with unit cell constants a = 12. 434 (4 ), b = 6. 00l2(6), c=l8. 49l(2) A, β=100. 87(l)° Z = 4, V = 1355. O(5) A, D'= 1. 350g/cm3, μ(MoKa) = 2. 41 cm-l, F(000) = 576, R=0. 029, Rw.= 0. 041 for 14l2 ob-served reflections (I> 3σ(I) ). X-ray analysis reveals that the dihedral angle betweenplane l (C(l)~C(6), F, N ) and plane 2 (C(8)~C(14), O ) is 4. l8° and theC(7) -S bond is longer than normal single C-S bond.展开更多
The structure of a room temperature asymmetrical dicationic ionic liquid （ADIL）, 1-（pyridinium-l-yl） propane- （1-methylpiperidinium） bi[bis（tfifluoromethanesulfonyl）imide] （[PyC3Pi][NTf2]2）, was studied by t...The structure of a room temperature asymmetrical dicationic ionic liquid （ADIL）, 1-（pyridinium-l-yl） propane- （1-methylpiperidinium） bi[bis（tfifluoromethanesulfonyl）imide] （[PyC3Pi][NTf2]2）, was studied by the X-ray difo fraction method. Meanwhile, thermal analysis of [PyC3Pi][NTf2]2 was also studied using non-isothermal thermo- gravimetric analysis （TGA）. The title crystal belongs to the triclinic with space group Pi and unit-cell parameters a ： 0.95217 （8） nm, b = 1.05129 （11 ） nm, c = 1.70523 （14） nm, ct = 89,759 （8）°,β = 80.657 （7）°, γ=68.007 （9）°, and F（000） = 792. Thermal stability and thermal decomposition kinetics of the title compound were also investigated using TGA under the atmosphere of highly pure nitrogen. Heating curves at different rates were cor- related with kinetic equations Friedman and ASTM （also called iso-conversion method）. The values of average activation E （kJ·mol^-1 ） and pre-exponential constant lgA are 149.58 kJ. mol- 1 and 8.83, respectively, which were obtained by the two methods. The kinetic model function, activation energy and pre-exponential constant of this reaction using the multivariate non-linear-regression method were f（a） = （1 -a）（1 ＋ 4.1870a）, 151.04 kJ·mol^-1 and 8.81, respectively, which were basically consistent with iso-conversion methods.展开更多
文摘Antofloxacin free base is prepared from antofloxacin hydrochloride by removing hydrogen chloride. Its crystal is obtained by slow evaporation of an acetonitrile-methanol mixed solution. Single-crystal X-ray diffraction reveals that the crystallography belongs to a triclinic PI space group with cell parameters： a = 0. 663 07（13） nm, b = 0. 898 39（18） nm, c = 1. 569 0（3） nm, α = 75.12（3）°,β = 87.92（3）°, γ = 77.57 （3）°. Antofloxacin shows no fluorescence in solution, but the crystalline state emits strong green light at 510 nm under the excitation of 360 nm, indicating a fluorescence enhancement induced by aggregation. It demonstrates that intermolecular packing and interaction in the crystal lead to the improved fluorescence quantum yield. These results provide important intbrmation for the further exploration of the structure-activity relationship of antofloxacin and the development of new drugs.
文摘The title compound 2-(4-fluorophenylamino)-2-thiomethyl acetophe-none (C15H14FNOS, M. = 275. 34 ) was synthesized by the reaction of 2-hydroxy-2-thiomethyl acetohenone (abenzoylhemithioacetal ) with 4-fluoroaniline. The crystal ismonoclinic, space group P21/n. with unit cell constants a = 12. 434 (4 ), b = 6. 00l2(6), c=l8. 49l(2) A, β=100. 87(l)° Z = 4, V = 1355. O(5) A, D'= 1. 350g/cm3, μ(MoKa) = 2. 41 cm-l, F(000) = 576, R=0. 029, Rw.= 0. 041 for 14l2 ob-served reflections (I> 3σ(I) ). X-ray analysis reveals that the dihedral angle betweenplane l (C(l)~C(6), F, N ) and plane 2 (C(8)~C(14), O ) is 4. l8° and theC(7) -S bond is longer than normal single C-S bond.
基金the National Natural Science Foundation of China(21176228)the National Key Technology Support Program of China(2013BAC01B04)the Science and Technology Research Projects of Zhengzhou City(141PQYJS555)
文摘The structure of a room temperature asymmetrical dicationic ionic liquid （ADIL）, 1-（pyridinium-l-yl） propane- （1-methylpiperidinium） bi[bis（tfifluoromethanesulfonyl）imide] （[PyC3Pi][NTf2]2）, was studied by the X-ray difo fraction method. Meanwhile, thermal analysis of [PyC3Pi][NTf2]2 was also studied using non-isothermal thermo- gravimetric analysis （TGA）. The title crystal belongs to the triclinic with space group Pi and unit-cell parameters a ： 0.95217 （8） nm, b = 1.05129 （11 ） nm, c = 1.70523 （14） nm, ct = 89,759 （8）°,β = 80.657 （7）°, γ=68.007 （9）°, and F（000） = 792. Thermal stability and thermal decomposition kinetics of the title compound were also investigated using TGA under the atmosphere of highly pure nitrogen. Heating curves at different rates were cor- related with kinetic equations Friedman and ASTM （also called iso-conversion method）. The values of average activation E （kJ·mol^-1 ） and pre-exponential constant lgA are 149.58 kJ. mol- 1 and 8.83, respectively, which were obtained by the two methods. The kinetic model function, activation energy and pre-exponential constant of this reaction using the multivariate non-linear-regression method were f（a） = （1 -a）（1 ＋ 4.1870a）, 151.04 kJ·mol^-1 and 8.81, respectively, which were basically consistent with iso-conversion methods.
