Preparation, Characterization And Catalytic Properties Of Amphiphilic Cyclopalladated Arylimines And Their Langmuir-Blodgett(LB) Films

In this thesis, a series of novel amphiphilic arylimines and their cyclopalladated arylimines were synthesized and characterized, and, Langmuir-Blodgett (LB) films of amphiphilic cyclopalladated arylimines were fabricated and characterized. The catalystic propertiese of these cyclopalladated arylimines and their LB films were also investigated for Heck and Suzuki-Miyaura coupling reaction.1. Synthesis and characterization of novel amphiphilic arylimines (la-lc)Three new amphiphilicarylimines la-lc were synthesized by reacting4-Hydroxy-benzaldehyde with dodecylamine,1-hexadecanamine and1-octadecanamine(Figure1). Furthermore, la-lc were characterized by1HNMR, IR, MS.2. Synthesis of novel amphiphilic cyclopalladated arylimines (2a-2c) and their applications in Heck reactionThree new amphiphilic cyclopalladated arylimines2a-2c were prepared and were characterized by1H NMR, IR, MS and elemental analysis(EA)(Figure2).2a-2c displayed good cataltstic activity in the Heck reaction. The results showed that aryl halides with electron withdrawing groups gave high yields, whereas aryl halides with electron donating groups gave low yields under the same condition, in which the yields of the para-position substitute were higher than that of the ortho-position and the meta-position due to the electron and steric effect. Some bromination heterocycles also showed pretty good yields. Furthermore, using water as solvent instead of DMF, the results of experiments were basically the same as the previous conclusion.3. Synthesis of novel amphiphilic arylimines cyclopalladated complexes (3a-3c) and its catalystic properties for Heck coupling reactionThree new amphiphilic cyclopalladated arylimines3a-3c were prepared and they were characterized by1H NMR, IR, MS(Figure3).3a-3c displayed good activity in Heck reaction. In the same condition, high yields could be obtained for aryl halides with electron withdrawing groups, while aryl halides with electron donating groups gave low yield. It also turned out some bromination heterocycles also showed high yield, and the para-position performed better than the ortho-position and the meta-position in the yield. The special phenomenon in the reaction was that the yield of p-nitrobromobenzene is only38%. Moreover, when the solvent is replaced by water, the experiment results are basically the same as the above, but the catalyzed yields could be improved to73%.4. Study on the catalytic activities of amphiphilic cyclopalladated arylimines (2a-2c,3a-3c) in Suzuki reaction(Figure4) Whether with electron withdrawing groups or electron donating groups, the aryl halides can catalyze effectively with using CH3CH2OH:H2O=2:1as solvent. Meanwhile, the para-position has a better performance than para-position in the yields, and the bromination heterocycles can reach a moderate yield in the reaction. The yield was73%with the addition of n-Bu4NBr with increasing the reaction time to48hours using water as solvent. However, the yield could be obtained up to90%if twice amount of catalyst were added in the same condition.5. Studies on the preparation and catalytic activities of the amphiphilic cyclopalladated arylimines (2a-2c,3a-3c) Langmuir-Blodgett (LB) filmsAryllimines cyclopalladated complexes2b LB films were fabricated on the solid substrate and characterized by AFM and XRD. The results showed that LB films fabricated on the hydrophilic glass substrates under the optimum conditions were uniform and well-ordered. The LB films used in the Suzuki reaction showed good catalystic properties, and the yields were improved with increasing of the layer deposited.