The Construction Of POM-RP-Based Hybrid Materials And Their Catalytic Synthesis Of Cyclohexanone Ethanone Ketal

Organophosphoryl polyoxometalates derivatives are a class of compounds formed by bonding organophosphoryl groups to the surface of POMs.Due to the structural characteristics and the performance advantages of these POMs derivatives,these compounds have great potential applications in catalysis,drugs,etc.In this thesis,the structural characteristics and performance advantages of organophosphoryl polyoxometalates derivatives were used to synthesize three kinds of organic-inorganic hybrid materials based on organophosphoryl polyoxometalates derivatives by reacting with organic ligands and transition metals under hydrothermal conditions.In the introduction of 2,2'-bipyridyl ligand and Co²⁺salts,the use of HCl acidic to adjust solution to different pH values,we can get two unique structure of POMs-based hybrid materials:H[Co?bipy?₃][?C₆H₅PO₃?₂Mo₅O₁₅]?4H₂O?1?;H[Co?bipy?₃][?C₆H₅PO₃?₂Mo₆O18]?2H₂O?2?;When Co Cl₂?2H₂O is replaced by Co?CH₃COO?₂?2H₂O,another different POMs-based hybrid materials can be obtained:[Co₂?H₂O??bipy?₃?C₆H₅PO₃?₂Mo₅O₁₅]?2H₂O?3?.The composition,structure,morphology,thermal stability and heat resistance of organic-inorganic hybrid materials based on organophosphoryl polyoxometalates derivatives were systematically analyzed and characterized.The analysis and characterization methods were:X-ray single crystal diffraction,Infrared Spectroscopy,thermogravimetric analysis,P-XRD,elemental analysis and XPS.In addition,the following studies were also conducted:?1?the solid UV-visible absorption spectras of these organic-inorganic hybrids based on organophosphoryl polyoxometalates derivatives showed that they were potential semiconducting materials,their band gap values were 2.92 ev,2.66 ev,and 2.59 ev,respectively;?2?in order to evaluate the acid catalytic activities of these three compounds,the condensation reaction of cyclohexanone and ethylene glycol was used as a probe reaction to explore the best experimental conditions in the synthesis of ketal.The experimental conditions of affectting the yield of ketal that we examined are:reaction time,the amount of catalyst and cyclohexane?water-carring agent?and the molar ratio of ketone to alcohol.The results of these experiments show that the optimal experimental conditions of the ketal reaction were as follows:the amount of cyclohexanone is 0.1 mol,n?cyclohexanone?:n?ethylene glycol?=1:1.5,the catalyst was 0.25 g,the amount of hexane was 14 mL and the reaction time was 3 h.The acetal yields of these compounds in optimal experimental conditions were 93%,91%and 84%respectively.The organic-inorganic hybrid materials based on organophosphoryl polyoxometalates derivatives also exhibited good stability and reusability.Compound 1,compound 2 and compound 3 still showed good catalytic activities for three cycles.