Iron Complexes Of Multidentate Nitrogen-containg Ligands And Their Catalysis On The Direct Oxidation Of Benzene To Phenol

This dissertation is mainly concerned with following four aspects:I. Quantitative analysis of benzene and phenolThe quantitative analysis of benzene and phenol from the reaction of benzeneoxidation by H2O2were using gas chromatography were scrutinised. By examingfour analytic method (normalization method, standard addition method, standardcalibration curve method and internal standard method), and optimized the catalyticconditions. It was found that the internal standard (toluene)-a standard curvemethod is the most precise and reliable method. In this method, the influence of thefluctuations in chromatographic conditions and the variations of the differentreaction batches can be effectively eliminate. Thus, this method is of high preciseand reproduction.II. Synthesis, characterization and catalytic activity of iron complexesFour multidentate ligands L1-L4derived from dis(pyridin-2-yl)amine (L1) weresynthesized. Reaction of these ligands with iron compounds in methanol led to theformation of iron complexes Fe1-Fe7, respectively. These complexes have fully beencharacterized. The structures of complexes Fe1-Fe7have been determined using X-raysingle crystal diffraction analysis. All the seven complexes catalyze directhydroxylation of benzene to phenol with hydrogen peroxide as oxidant in a mixedmedium of water and acetonitrile. The reactivity of the complexes correlate well totheir reduction potentials, the more negative the potential, the moer reactive thecatalyst. It also studied the iron complex Fe7catalyze oxidation of other aromatichydrocarbons, the results indicate that the stronger electron-withdrawing of thesubstituents, the lower the conversion capabilities of the substrate.III. Catalyst system of the supported iron complexesTwo matrix-supported iron-based catalytic systems were designed and prepared.The frist system (Polymer1) resulted from the incorporation of complex Fe1intomesoporous materials. The other type (Polymer2and Polymer3) was achieved by chemistry in molecular ligands L1and L2onto polystyrene resin, respectively,followed by coordination of Fe (III). Preliminary exploration of the catalytic activityof the three supported catalysts for benzene hydroxylation was performed. Thesupported catalysts were proved relatively steady in activity after reused several timewith the yield of phenol remain at around14%.IV. Study on the copper complex and the catalytic activityAppendix section described synthesis and characterization of the copper complex[CuL2Cl2], and then investigated the catalytic activity of benzene selective oxidationto phenol with the copper complex.