Synthesis Of Ionic Rh/Ru Complexes And Their Applications In Homogeneous Catalysis

In this thesis, several ionic high-valent Rh(Ⅱ, Ⅲ) and Ru(Ⅲ) complexes, which are insensitive to moisture and oxygen, have been synthesized for the first time through the complexation of the phosphine-furictionalized imidazolium /benzimidazolium based ionic liquids (also defined as the ionic phosphines) with the Rh(Ⅱ, Ⅲ) and Ru(Ⅲ)-precursors (Scheme 1), and fully characterized by the means of 1H/31P/13C NMR, FT-IR, single crystal X-ray diffraction, and CHN-elemental.Then the obtained ionic Rh(Ⅱ, Ⅲ) complexes were applied as the catalyst precursors for hydroformylation of 1-octene and the ionic Ru(Ⅲ) ones for H2-hydrogenation/transfer hydrogenation of aldehydes and ketones respectively. It was found that the ionic Rh(Ⅱ) complex (Rh-5) just exhibited the moderate activity towards hydroformylation of 1-octene to nonanals. However, its catalytic performance could be boosted up dramatically with the addition of water. The high-pressure in situ FT-IR analysis verified that formation and stability of Rh-H active species was able to be facilitated with the involvement of water, which corresponded to the more favored hydroformylation of 1-octene. The catalytic performance of the ionic Rh(Ⅲ) complex (Rh-6) was proved to be quite poor for hydroformylation of 1-octene, which could be improved dramatically in the presence of the low-toxic and cheap tertiary amines as auxiliary additives. Highlighted by the efficient effect of the tertiary amines on the catalytic performance of the ionic Rh(Ⅲ) complex, the alkylpiperidyl-functionalized ionic liquid was purposely prepared and applied as the solvent for the ionic Rh(Ⅲ) complex to afford ’ionic liquid-organic’ biphasic hydroformylation of 1-octene. As a result, the ionic Rh(Ⅲ) complex captured and promoted by the alkylpiperidyl-functionalized ionic liquid could be recycled for 5 runs after the facile separation from the organic products.The ionic Ru(Ⅲ) complexes generally exhibited good catalytic performance for H2-hydrogenation/transfer hydrogenation of acetophenone in the presence of bases. Especailly for the ionic Ru(Ⅲ) complex of Ru-3 containing P, N-hybrid ligand, the best yield of the product was obtained owing to the hemilabile effect of P, N-hybird ligand for the timely protection catalyst.