Type 2 - Methyl Imidazoles Side Chain Bridging Metallocene Complexes Synthesis, Reactivity And Catalytic Activity Of Study

In recent years, the so-called Constrained Geometry complexes (CGCs) for olefin polymerization are the objects in the focus of the studies in the modern organometallic chemistry. On the other hand, the Frustrated Lewis pairs (FLPs) are also becoming very popular and attract a great deal of attention due to their recently discovered capability to activate small molecules.The present research mainly focuses on the synthesis of a particular C2-bridged cyclopentadienyl-amido type CGCs and studies of its reactivity towards electrophilic reagents SiMe3Cl and Lewis acid AlBn3、B(C6F5)3. In addition, attempts of activation of CO2by FLPs based on the complex were undertaken.The preparation route for C5H5-CPh2CH2-(imidazol-2-yl) ligand2b was improved that increased both the yield and the purity. The target Cp-tris(amido) type complexes,2-[2-(η5-cyclopentadienyl)-2-methylpropyl]-1H-imidazolyl-bis(N,N-diethylamido)titanium(ⅳ)(3a) and2-[2-(η5-cyclopentadienyl)-2,2-diphenylethyl]-1H-imidazolyl-bis(N,N-diethylamido) titanium (ⅳ)(3c) have been synthesized.Reactions of the amido-complex3c with electrophilic reagents, trimethylchlorosilane and thribenzylaluminum, has afforded trichloro-2-[2-(η5-cyclopentadienyl)-2,2-diphenyl-ethyl]-1-trimethylsilyl-1H-imidazolyl-titanium(ⅳ)(5a) and2-[2-(η5-cyclopentadienyl)-2,2-diphenylethyl]-1-[tris(phenylmethyl)alumnuidyl]-1H-imidazole-bis(N,N-diethylamido)titaniu m(ⅳ)(6b). Compounds3a,3c,5a, have been synthesis and characterized by’HNMR,13CNMR spectroscopy and X-ray diffraction analysis, and6b has been synthesis and characterized by X-ray diffraction analysis.B(C6F5)3as a strong Lewis acid can react with amine complexes3c in order to get an FLP capable to activate CO2. The symmetry of the structure of the3c-B(C6F5)3reaction product is lower than that of3c. Unfortunately, we failed to gain single crystals of this compound suitable for the X-ray diffraction analysis.