Study On Synthesis,Thermodynamics Proporities And Catalytic Performance Of P-toluenesulfonate

In this paper,three p-toluenesulfonates(iron,cobalt,nickel)were synthesized and characterized.The catalytic performances of these three salts in the oxidation of benzyl alcohol and butanol were investigated,and the solid-liquid equilibrium and some other thermodynamic properties of three salts were systematically studied.The metal p-toluenesulfonates(Fe(OTs)3·6H2O,Co(OTs)2·6H2O,Ni(OTs)2·6H2O)were synthesized via the reaction of p-toluenesulfonic acid(PTS)and metal hydroxide(M(OH)n).The results show that 80?,3 h,and N(PTS):N(M(OH)n)=1.1:1,the yield of Fe(OTs)3·6H2O,Co(OTs)2·6H2O,and Ni(OTs)2·6H2O were 91.2%,91.7%and 90.9%,respectively.The products were characterized by EDS,IR,DSC and TGA.By using 30%H2O2 as oxidant,chloroform and acetonitrile as solvent,the catalytic effects of the above three salts on the oxidation of benzyl alcohol were investigated.The results show that the catalytic effect of Fe(OTs)3·6H2O is best among three salts;the yield of benzaldehyde in chloroform solvent is the highest,and acetonitrile is more favorable to produce benzoic acid.The conditions are:chloroform,16 h,60 ?,n(benzyl alcohol):n(H2O2):n(Fe(OTs)3·6H2O)=1:6:0.01,the conversion of benzyl alcohol is 89.3%,the yield of benzaldehyde is 85.6%,and TON is 85.5;acetonitrile,10 h,70 ?,n(benzyl alcohol):n(H2O2):n(Fe(OTs)3·6H2O)=1:7.5:0.009,the conversion of benzyl alcohol is 97.4%,the yield of benzaldehyde is 72.4%,and TON is 80.4.Molecular dynamics simulation results show that the interaction between chloroform and benzaldehyde molecules was significantly greater than that between other solvents and benzaldehyde molecules,indicating that chloroform can protect the benzaldehyde molecule so as to prevent it from being further oxidized into benzoic acid.Two possible mechanisms of benzyl alcohol oxidation reaction were proposed,and 1,4-benzoquinone was used as a radical scavenger to verify the rationality of the free radical mechanism.The catalytic proformance of Fe(OTs)3·6H2O on butanol oxidation was investigated.It was found that C-C chain cleavage occurred during the oxidation of butanol,and a reasonable deduction was made on this mechanism of chain cleavage:butyraldehyde will be partially converted to the enol compound(CH3CH2CH=CH(OH)),this material can be oxidized to CH3CH2COCHO,and C?-C? will be broken to form formic acid and propionic acid;when CH3CH2COCHO accumulates to a certain amount,C?-C? will also broken to generate acetic acid.The solid-liquid equilibrium(SLE)data of Fe(OTs)3·6H2O,Co(OTs)2·6H20,Ni(OTs)2·6H2O in(ethanol+water)mixtures with ethanol mole fraction(x0)of 0.000-0.342 were measured among 288.15-333.15 K by using a synthetic method.The experimental data were correlated by the modified Apelblat model,the CNIBS/Redlich-Kister model and the Hybrid model.The results showed that these three models can be well agreed with the experimental data,and ARD<3.07%.The modified van't Hoff equation was used to calculateenthalpy(?H0soln),Gibbs energy(?G0soln)and entropy(?S0soln)in the dissolution process,and the thermodynamic transfer function of the dissolution process,including ?A?BH0soln,?A?BG0soln,?A?BS0soln,were calculated by the above thermodynamic properties.The results show that the driving force of Fe(OTs)3·6H2O dissolution process is enthalpy,and the driving force for dissolving Co(OTs)2·6H2O and Ni(OTs)2·6H2O changed from entropy to enthalpy at x0=0.114.The SLE data of Co(OTs)2·6H2O andNi(OTs)2·6H2O in x0=0.000-1.000(ethanol+water)mixtures at 298.15 K were further studied and were correlated by the CNIBS/Redlich-Kister model,and a variation phenomenon of dissolution process was found.By mathematically analyzing the above model and calculating the hydrogen bonding between solute and solvent molecules,it can be inferred that this variation phenomenon is related to the formation of two(ethanol+water)clusters in the solvent,and the formation and disappearance of these two clusters is closely related to five x0 values.Finally,the phase equilibrium properties of benzyl alcohol and butanol oxidation products were studied.The SLE data of benzoic acid in benzyl alcohol,benzaldehyde,acetonitrile,n-hexane,cyclohexane and ethyl acetate at 288.15-333.15 K were determined and correlated by the modified Apelblat model,the ?h model and the Wilson model.Among the above solvents,the suitable recrystallization solvent of benzoic acid was benzaldehyde.The liquid-liquid equilibrium(LLE)data of(butanol+butyrate acid+water)and(butanal+ butyrate acid+water)ternary systems at 293.15 K,308.15 K and 323.15 K and the(butanol+butanal+butyric acid+water)quaternary system at 298.15 K were determined by a equilibration method,and were correlated by the NRTL model and the UNIQUAC model.The results showed that these two models can be well agreed with the experimental data,and RMSD<1.27%.The distribution coefficient(D)and separation factor(S)were calculated to provide basic data for the extraction and purification of butyric acid.