Theoretical Calculation Of ～1H NMR, IR Spectra Of Donor

The design of a suitable donor has great effect on the catalytic activity and the stereospecificity of the product. After the appearance of MgCl₂ carrier catalyst, the effect of donor become more important. The synthesis and the theoretical research of donors attracts lots of people's attention. In TiCl4/MgCl₂-AlEt₃ catalyst system, the structure confirmation of donor is the basic of the catalystic mechanism research.Stereochemistry model of dicyclohexyldimethoxysilane and other sliane compounds have been established by means of parameter setting in this dissertation. The IR and ¹H NMR spectra of dialkyldimethoxysilane and ¹H NMR spectra of 2,4-pentanediol heterocyclic acid diester, 2,4-pentanediol alkyl benzoic acid diester based on the model have been calculated. 'H-NMR spectra can be assigned reasonably and correctly by theory calculation.(1) IR spectra are calculated using B3LYP method 3-21g, 6-31g, 6-31g(d) basis sets and ¹H NMR spectra are calculated using GIAO method. The largest error between experimental and theory calculation IR spectra is 9.41%. As the size of the basis set increased, the calculated values become closer to those of experimental, the discrimination of experiment and theory calculation is less than 0.4PPM(2) Theory calculation can assigned donor compounds reasonably. The optimised structure of dicyclopentyldimethoxysilane, diisopropyldimethoxysilane dicyclohexyldimethoxysilane have C2V symmetry, others have C_s symmetry, esters have (R,R), (R,S), (S,S) three conformation.(3) When analyzing at 130℃, the ¹H NMR spectra of dicyclopentyldimethoxysilane and dicyclohexyldimethoxysilane are same to the room temperature. Other silanes are similar to this two compounds, so we can conclude that their structure are freezed. This is why they can control the behavior and capability of alkene polymerization.