Synthesises And Study Of Crystal Chemistry On A Series Of N-Methylstilbazolium Salts

A series of 4-N-methylpyridinium tetraphenylborate salts have been synthesized and their structures were confirmed by elemental analysis, IR spectroscope and 1HNMR spectroscope. Three crystals were grown by slow evaporation at ambient temperature and their structures are determined by X-Ray analysis.Except for three determined crystal structures, 29 compounds of crystal structures were retrieved from the Cambridge Structural Database (CSD). Using our program CSD2OPEC, we first decoded the format of CSD. Then the crystal model and the packing energy were calculated using the program OPECH. Using the GC8, geometrical parameters and intermolecular interactions were obtained. Then 32 compounds of crystal structures were divided. We researched the crystal packing mode of different anions by analyzing and comparing, and drew the following conclusions.1. The molecule tends to come forth centrosymmetry, if the cations have the centrosymmetricπ…πinteractions.2. If the anion is I-, Br- or BF4-, the compounds are accumulated in noncentrosymmetric space groups because the volume of them is not large enough to overcome dipole-dipole interactions.3. If molecules have the group of strong intermolecular hydrogen bonds, they are possibly accumulated in noncentrosymmetric space groups.4. When there are some solvent molecules existing in the crystals, the crystal space groups have no centrosymmetry. The solvent molecules have an important effect on the crystal packing mode, but their presence confines their application in some degree.5. We can select the anions which have larger volume or which have many...