Study On The Regularity Of Oxidation Of Cycloalkanes?C₅-C₈? With O₂ Catalyzed By Monosubstituted Aryl Metalloporphyrins

Cycloalkanes are important hydrocarbons,which exist in the process of the petrochemical industry.Its main oxidation products are cycloalkanones,cycloalkanols,cycloallyls hydroperoxides and corresponding diacids.They are widely used in food,dyes,medicine,agriculture,lubricants,surfactants and other fields.However,the main problems in the current process of cycloalkane oxidation in industrial production are high reaction temperature,low substrate conversion rate and low target product selectivity.This dissertation mainly studied the catalyst-free and solvent-free oxidation of cycloalkanes?C₅-C₈?with molecular oxygen,focusing on the study of auto-oxidation temperature and product distribution.The effect of reaction temperature,reaction pressure,amount of substrate and catalyst concentration on the catalytic oxidation of cycloalkanes?C₅-C₈?was studied using mono-substituted aryl metalloporphyrins as catalysts at temperatures where auto-oxidation of cycloalkanes could not occur.Part of the common problems of O₂-oxidized cycloalkanes?C₅-C₈?catalyzed by mono-substituted porphyrins were proposed.The primary content of this dissertation could be summarized as follows:1.This study is the first systematic document up to now which revealed the autoxidation temperature and product distribution of the catalyst-free and solvent-free oxidation of cycloalkanes?C₅-C₈?with molecular oxygen.The autoxidation occurs at120?,130?,120?,and 105?for cyclopentane,cyclohexane,cycloheptane and cyclooctane respectively,with obvious oxidized products formation.A considerable yield can be obtained at 140?,145?,130?and 125?,respectively.The oxidation products of cyclopentane are distributed as follows:cyclopentyl hydroperoxide?0.55%?<succinic acid?2.08%?<cyclopentanone?2.75%?<glutaric acid?3.88%?,no significant cyclopentanol;cyclohexane oxidation product yields are as follows:cyclohexyl hydroperoxide?0.15%?<diacid?0.39%?<adipic acid?1.44%?<cyclohexanol?3.18%?<cyclohexanone?4.59%?.The major oxidation products of cycloheptane and cyclooctane are distributed as follows:cycloheptanone?3.21%?<Cycloheptyl hydroperoxide?6.09%?andcyclooctanone?4.78%?<cyclooctylhydroperoxide?10.51%?.This study will act as an important reference for the determination of the temperature of catalytic oxidation of cycloalkanes.2.Using T?p-Cl?PPCo as catalyst,the effects of reaction temperature,oxygen pressure,reaction time,amount of catalyst and structure of substrate on O₂ oxidized cycloalkanes were systematically studied.It was found that the reaction temperature and the structure of the substrate are the main factors affecting the oxidation of naphthenes.When the reaction pressure is 0.8-2.0MPa and the metalloporphyrin concentration is 6-30ppm,the above two factors have no obvious yield and distribution of cycloalkane oxidation products.They yielded considerable yields at120??120??110?and 105?respectively,and products of the oxidation were distributed as follows:cyclopentyl hydroperoxide?68?<cyclopentanol?172?<cyclopentaneone?445?<glutaric acid?526?;cyclohexyl hydroperoxide?164?<adipic acid?270?<cyclohexanone?1200?<cyclohexanol?1213?;Pimelic acid?48?<cyclohept-anol?533?<cycloheptanone?1442?<cycloheptyl hydroperoxide?2398?;suberic acid?69?<cyclooctanol?204?<cyclooctanone?4205?<cyclooctylhydrop eroxide?9290?.3.Extending metal porphyrins from T?p-Cl?PPCo to T?p-Cl?PPMn,T?p-Cl?PPFe,T?p-Cl?PPZn,T?p-Cl?PPCu,T?p-Cl?PPNi,T?p-Cl?PPPd,T?o-Cl?PPCo,T?m-Cl?PPCo,T?p-CH₃?PPCo and T?p-OCH₃?PPCo,studied the generality of the distribution of cycloalkane oxidation products catalyzed by metalloporphyrins.The metal porphyrin center metal was found to be the main factor influencing the oxidation behavior of naphthenic hydrocarbons.Under the same conditions of the central metal,the porphyrin ligands had little effect on the yield and distribution of the cycloalkane oxidation products.The four metalloporphyrins of T?p-Cl?PPZn,T?p-Cl?PPCu,T?p-Cl?PPNi and T?p-Cl?PPPd have no catalytic activity.The product distribution of cyclohexane in the catalysts T?p-Cl?PPCo,T?p-Cl?PPMn,and T?p-Cl?PPFe is as follows at 120?in TON.Cyclohexyl hydroperoxide?84?<adipic acid?330?<cyclohexanone?1206?<cyclohexanol?1351?;adipic acid?208?<cyclohexyl hydropero-xide?628?<cyclohexanone?804?<cyclohexanol?1340?;adipic acid?0?<cyclohexanone?300?<cyclohexanol?32?<cyclohexyl hydroperoxide?510?.The catalytic activities of them in the cyclopentane oxidation is also different,the product of the oxidation products is distributed differently.The result of cycloalkane oxidation is mainly determined by the structure of cycloalkane and the metal in metalloporphyrin.The distribution of cycloalkane oxidation products by metalloporphyrins of different porphyrin ligands is basically unchanged.4.The effects of cobalt acetate,cyclohexanol and cyclohexanone on the catalytic effect of metalloporphyrins on the catalytic oxidation of cycloalkanes were investigated.Cobalt acetate was found to change the ratio of cycloalkanes and cycloalkanols in the products of cycloalkane oxidation.The ratio of cyclopentanol to cyclopentanone is from 1:2.8 to 1:4.5.The ratio of cyclohexanol to cyclohexanone is from 8:7 to 9:7.Cycloalkanol promoted the production of cycloalkanone.The addition of cyclopentanol increased the ratio of cyclopentanone to cyclopentanol from2.8:1 to 6.5:1.The ratio of cyclohexanone to cyclohexanol increased from 7:8 to 9:8.Cycloalkanone can increase the yield of cycloalkanone,cycloalkanol,cycloalkyl hydroperoxide and diacid in cycloalkane oxidation products.The yield of cyclopentane oxidation product increases from 1.507%to 1.782%,the yield of cyclohexane oxidation increased from 3.566%to 4.581%.The addition of cycloalkanols and cycloalkanones can increase the ratio of cycloalkanes and cycloalkanols in the cycloalkane oxidation products.The ratio of cyclopentanone to cyclopentanol oxidation products increases from 2.8:1 to 20:1.The ratio of ketone to cyclohexanol increased from 4:3 to 5:3.