Synthesises And Study Of Crystal Chemistry On Benzylidene-aniline Derivatives

A number of benzylidene-aniline derivatives have been synthesized andtheir structures were confirmed by JR spectroscope data, elemental analysis. Some of their crystal structures are determined by X-ray analysis after the single crystals were grown by slow evaporation at room temperature.Some crystal structure data are selected from CSD (The Cambridge Structural Database). A systematic calculation, analysis and comparison for the selected data and the determined crystal structure data was done. In this thesis, a systematic crystal and quantum chemistry study of the effects of molecule structure on properties, which include planarity of molecule, dipole moment and NLO properties, was carried out. The way of the crystallization of the compounds is also discussed.AIf a crystal with good SHG property is hoped to get, the molecule mustpossess a large second-order hyperpolarizability ( ~ ) and also must crystallize in a non-centrosymmetric structure. The results of the study show, that P can be enhanced by better molecular planarity, by selecting strong acceptors on C phenyl and by selecting donors which has a small ground state dipole moment and a large excitated state dipole moment on N phenyl; and that molecules can be crystallized in a non-centrosynimetric structure in a large probability through forming hydrogen bonds network.Hai-Jing PengDirected by De-Chun Zhang...