环丙沙星-钨硅多金属氧酸盐的制备及热分解动力学

A new polyoxometalate （CPFX·HCl）3H4SiW12O40·10H2O was prepared from ciprofloxacin hydrochloride and H4SiW12O40·nH2O in aqueous solution, and characterized by elemental analysis, IR spectra and DTA-TG-DTG techniques. The IR spectrum confirmed the presence of Keggin structure and the characteristic functional group for ciprofloxacin in the compound. The TG-DTA-DTG curves showed that its thermal decomposition was a four-step process consisting of simultaneous collapse of Keggin type structure. The residue of decomposition was the mixture of WO3 and SiO2, confirmed by X-ray diffraction and IR spectroscopy. The decomposition mechanism and nonisothermal kinetic parameters of the polyoxometalate were obtained from an analysis to the TG-DTG curves by the single scanning methods （the Achar method and Coats-Redfern method） and the multiple scanning methods （the Kissinger method, Flynn-Wall-Ozawa method and Starink method）. The results indicate that the kinetic equationswith parameters describing the thermal decomposition reaction are dα/dt=6.65×10^63（1-α）^2/3]e^-10495.5/T with E=87.26 kJ/mol and A=6.65×10^6 s^-1 for the second step,dα/dt=7.01×10^9（1-α）e^-18770.7/T with E=156.06 kJ/mol and A=7.01×10^9 s^-1 for the third step,dα/dt=9.77×10^43（1-α）^2]e^-88980.0/T with E=739.78 kJ/mol and A=9.77×10^43 s^-1 for the fourth step.

Preparation and Thermal Decomposition Kinetics of Polyoxometalate of Ciprofloxacin with 12-Tungstosilicic Acid

A new polyoxometalate (CPFX·HCl)₃H₄SiW₁₂O₄₀·10H₂O was prepared from ciprofloxacin hydrochloride and H₄SiW₁₂O₄₀·n H₂O in aqueous solution, and characterized by elemental analysis, IR spectra and DTA‐TG‐DTG techniques. The IR spectrum confirmed the presence of Keggin structure and the characteristic functional group for ciprofloxacin in the compound. The TG‐DTA‐DTG curves showed that its thermal decomposition was a four‐step process consisting of simultaneous collapse of Keggin type structure. The residue of decomposition was the mixture of WO₃ and SiO₂, confirmed by X‐ray diffraction and IR spectroscopy. The decomposition mechanism and non‐isothermal kinetic parameters of the polyoxometalate were obtained from an analysis to the TG‐DTG curves by the single scanning methods (the Achar method and Coats‐Redfern method) and the multiple scanning methods (the Kissinger method, Flynn‐Wall‐Ozawa method and Starink method). The results indicate that the kinetic equations with parameters describing the thermal decomposition reaction are dα/dt=6.65×10⁶3(1?α)^(2/3)]e^(?10495.5/T) with E=87.26 kJ/mol and A=6.65×10⁶ s^?1 for the second step, dα/dt=7.01×10⁹(1?α)e^(?18770.7/T) with E=156.06 kJ/mol and A=7.01×10⁹ s^?1 for the third step, dα/dt=9.77×10⁴³(1?α)²]e^(?88980.0/T) with E=739.78 kJ/mol and A=9.77×10⁴³ s^?1 for the fourth step.