Synthesis, Characterizations And Gasoline Antiknock Properties Of Transition Metal Complexes

Today it is urgent to search and produce more economical and effective antiknock additives for automobile engines to use unleaded clean fuels, which can satisfy the increasing demand for environmental protection and energy conservation. In the first part of the dissertation, the basic knowledge of development and species of the gasoline antiknock (especially nonleaded) is introduced and reviewed. The content of this subject study is presented on the basis of studies on dendritic macromolecule and transition metal complex.The second part of this dissertation shows the synthesis and characterization of some different kinds of transition metal complexes of a new dendritic macromolecule and pyrimidine. The dendritic macromolecule was prepared using ethylenediamine as core and maleic anhydride as branched units. Its ligand of the dendritic macromolecule was obtained by salicylaldehyde's modifying the peripheral functional group of the dendritic macromolecule. From the reaction of the ligand with transition metal salts, a series of transition metal complexes were synthesized successfully: Cu(II), Mn(II), Ni(II), Cu(I) /(II), Fe(II) /(III), carbonyl iron and mixed metals (Fe(III), Cu(II), Mn(II), Ni(II)) complexes. The ligand of pyrimidine was synthesized by thiourea and 2,4-pentandione diacetylmethane and its complexes as follows: Cu(HL)₂(H₂O)₂Cl₂, [Co(HL)₃(H₂O)₂Cl]Cl·2H₂O and [Ni(HL)₃(H₂O)₂Cl]Cl·2H₂O. These complexes were characterized by gel permeation chromatography, infrared spectrum, ultraviolet spectra, X-ray photoelectron spectra (XPS) and thermal analysis (TG-DTG). Some more detailed data on the changes of the ligand and their complexes, which can provide the changes of internal electronic state about the suggested structures of the complexes, was obtained from XPS spectrometry. From these results it can be concluded that the ligand of the dendritic macromolecule and pyrimidine have been synthesized and integrated with the transition metal ions by coordinated bond.In the third part of this dissertation, the transition metal complexes prepared used as gasoline antiknock have been studied. The stability and the improvement effect on the gasoline were also studied. The results showed that transition metal complexes derived from the dendritic macromolecule and pyrimidine had a good stability on thegasoline and less effective improvements has been shown with the complexes of the pyrimidine as additives, while different impacts with the complexes of the dendritic macromolecule as additives has been observed: Mn(II) and mixed metals (Fe(III), Cu(II), Mn(II), Ni(II)) complex of the dendritic macromolecule had negative effect on antiknock property, while the addition of the ligand and the other complexes can improve the antiknock number of the same gasoline. When 0.08 g of the antiknock additives were added into 100 ml gasoline, the Fe(II) /(III) and carbonyl iron complexes of the dendritic macromolecule can increase 2-3 units of octane number of the gasoline, whereas the Cu(II) and Ni(II) complexes did not exhibit an obvious improvement, they might be a fine antiknock additive because of less mass comparatively. In addition, the results revealed that there exited no single linear relations between the addition and the effect of the antiknock. There lies a better and more economical addition to different antiknock.In the forth part of this dissertation, a brief summarization on mechanics of the antiknock was made and the possible mechanics of the transition metal complexes of the macromolecule was proposed: the reaction occurred between the high-valent metal oxide and hydrocarbon peroxide free radical, which can effectively restrain the reaction velocity and obtain a better antiknock effect.In this dissertation, a series of transition metal complexes were synthesized and characterized, especially by XPS analysis, which enriched its species and physicochemical data. Moreover, there is no report in consulted literature about the transition metal complexes of the macromolecule using as an antiknock additive of gasoline. The synthesis process of the complexes conducted in our research is brief and the raw materials are abundant and relatively cheap. With less addition, the carbonyl iron, Fe(II) /(III), Ni(II) and Cu(II) complexes of the dendritic macromolecule may have good prospects of development and application as the gasoline antiknock.