Model Oil Desulfurization Based On The Host And Guest Properties Of Silver 3,5-Ditrifluoromethylpyrazolate

Tiophene and its derivatives often present in the oil.SO2 can contribute to a series of environmental issues when it burn.Hydrodesulfurization(HDS)is the current widely-used industrial method,but it limited applicability to the aromatic sulfur compounds.Based on the concept of supramolecular,we use the ?-acidity of triangular silver pyrazolates and the ?-basicity of aromatic sulfur compounds to form the host-guest compounds to desulfurization.In this paper,the trinuclear silver 3,5-ditrifluoromethylpyrazolate was prepared using a "greener" method.Nine adducts of silver 3,5-ditrifluoromethylpyrazolate with basic molecules were synthesized by low-temperature volatilization,which have been characterized by nuclear magnetic spectroscopy,infrared spectroscopy,PXRD,thermogravimetric analysis.Their crystal structures have been determined by X-ray single crystal diffraction.The ligand and abbreviations used in this paper are:3,5-ditrifluoro methy lp yrazole(pzH)dibenzothiophene(DBT)4,6-dimethy ld ibe nzo thio p he ne(DMDBT)benzothio phene(BT)2,5-dimethy l thiop he ne(DMI)The synthesized trinuclear complex and adducts are:{[3,5-(CF3)2pz]Ag}3 Ag3pz3 Ag3pz3·[PhCOOH]2 Ag3pZ3·[Et3NH·N O3]2 Ag3pz3·DBT Ag3pz3·DMDBT Ag3pz3·BT Ag3pz3·DMT Ag3pz3·DMF Ag3pz3·(DMA)2 Ag3pz3·(DMSO)2 The research of this thesis mainly focuses on the following two aspects:1.The host-guest adducts formed from silver trinuclear complex and thiophene compounds:These adducts were formed from ?-acidic silver complexes and electron-rich thiophene compounds or other Lewis-basic solvents in a ratio of 1:1.Based on the crystal structure parameters,the magnitude of the nuclear magnetic displacement and the DFT calculations,the interaction intensity between the trinuclear complex and the thiophene compound is descreased following the order:Ag3pz3·DBT?Ag3pz3·DMDBT>Ag3pz3·BT>Ag3pz3·DMT.2.Deep desulfurization of model oil using the silver trinuclear complex as precipitant:select Ag3pz3 was chosen as precipitant and CH3CN as extractant to precipitate and extract the thiophene derivatives in model oil.The factors such as reaction time,reaction ratio and number of extractions were investigated and the optimal conditions were obtained:10 mL of model oil was mixed with 1.3 equivalent of precipitant for 0.5 h,which was extracted by CH3CN(3 × 3.3 mL).The sulfur content of the DBT-containing model oil dropped from 100 mg/L S to 0.55 mg/L S,and that of the DMDBT-containing model oil from 100 mg/L S to 1.50 mg/L S.The precipitant still retained about 99%and 97.5%of its desulfurization efficiency after 5 times of recycling,respectively.