The Study On Structure Of Copolymer Rhodium Complexes And Their Catalytic Properties For Methanol Carbonylation And Copolymer Ruthenium Complex In Hydrogenation

The thesis includes two major parts.The first part mainly deals with the relationship between the structure of copolymer rhodium complexes and their catalytic properties for methanol carbonylation, and certain conclusions have been drawn as follows.1. A novel kind of copolymer rhodium complex containing free donors of S and O atoms was synthesized, whose intermolecular reaction was studied by using X-ray photoelectron spectroscopy and IR spectroscopy in comparison with those of minor organic molecular rhodium complexes imitating the structure of the copolymer ligand. With a catalytic activity comparable to the rhodium complexes of minor organic molecular ligands, the stability of the copolymer rhodium complex was largely improved due to the existence of free donor atoms taking place the reversible intramolecular substitution reaction, which prohibits the rhodium active center from decomposition under the condition of heating, oxygen and without the protection of CO.2. A series of coordination units of 2-vinyl pyridine and methyl acrylate/vinyl methyl ketone copolymer rhodium complexes were studied in comparison with those of 4-vinyl pyridine and methyl acrylate/ vinyl methyl ketone copolymer rhodium complexes. The influence of the microstructures of their active centers on the catalytic activity was investigated by well-directed experiments. It has been found that the complexes containing 2-vinyl pyridine copolymer ligands exhibit much higher catalytic activity than those of 4-vinyl pyridine copolymer rhodium complexes in methanol carbonylation. Some theoretic reasons have been suggestedfor the possession of the favored catalytic microstructure by the complexes containing 2-substituted vinyl pyridine copolymer ligands. These experimental observations also provided theoretical reference for the better design of the rhodium complexes as catalysts for methanol carbonylation .3 . The mechanism of catalytic carbonylation about copolymer rhodium complexes has been researched by employing minor organic complex with the same structure as the copolymer complexes. The experiments demonstrated that rhodium complexes of the same chelating microstructures using either copolymer or minor organic molecular ligands, displayed the same catalytic cycle for methanol carbonylation. And by the application of the established mechanism to methanol carbonylation catalyzed by similar copolymer rhodium complexes, the differences in their catalytic activity could be well explained, together with the reason why they excelled the classic Monsanto system in catalytic properties such as activity and stability.The hydrogenation of benzene to cyclohexane over polymer-supported ruthenium complex was mainly discussed in the second part of this thesis. 2-vinyl pyridine and l,2-(methacrylate) glycol cross-linked copolymer beads were firstly used as ligand to form the corresponding ruthenium complex, the subsequent reduction of which with sodium borohydride yielded the final catalyst with uniform distribution of metal ruthenium throughout the copolymer beads displaying good catalytic properties in hydrogenation of benzene . The experimental results showed that the catalytic activity could be enhanced with the increase in temperature , pressure and stirring rate of the reaction system.