| Materials are the basis for human beings to survive and develop. Among all thekinds of materials, porous materials have attracted the attentions of scientists for theirexcellent absorption properties, relatively low density, and high specific surface area.Recently porous coordination polymers (PCPs) or Metal-Organic Frameworks (MOFs),and a new kind of materials, Microporous Organic Polymers (MOPs) constructed bycovalent bonds, have received significant attentions for potential applications in gasstorage and separation, light-harvesting, drug storage and delivery, chemical sensor, andheterogeneous catalysis. In particular, potential applications of PCPs and MOPs asheterogeneous catalysts are promising since the different structures and functions can bedesigned and synthesized, and the shape and size of their nanochannels can be easilymodified by tuning the ligands and substituent groups.Polyolefin has been one of the widely used synthetic polymers in our daily life. Soit is important to develop highly active catalysts for olefin polymerization. In industry,single-site catalysts need to be immobilized on suitable supports such as silica, zeoliteor MgCl2. The immobilization of homogeneous catalysts normally causes a tremendousdecrease in catalytic activity and the loss in some advantages of the single-site catalysts,as well as the introduction of additional ashes into the polymer product. Development ofPCP catalysts based on highly active single-site olefin polymerization catalysts mayprovide us a super way for immobilizaing the homogeneous single-site catalysts withoutusing any support. Thus, we have synthesized a new type of PCP catalysts used inethylene polymerization.Transition metal-catalyzed cross-coupling reactions for the formation ofcarbon-carbon bonds have been recognized as powerful synthetic tools and play an important role in multiple organic transformations and pharmaceutical industry.However, many noble metals used in homogeneous system are very expensive and it isdifficult to separate the soluble catalyst from the reaction system. To address theselimitations, immobilization of the homogeneous catalyst is a promising option. This wasnormally achieved by supporting the active components on prefunctionalized solidmaterials such as activated carbon, silicates, zeolites, organic polymer, nanoparticles,and metal-organic frameworks. However, the reaction performance of the heterogeneouscatalysts was affected dramatically by the intrinsic properties of the support as well asthe link way between active components and support. Recently, a bottom-up strategy forthe construction of MOPs has been widely used. Using this strategy, the materialsprepared have more catalytic centers and better stability. With these considerations inmind, in this contribution, we report the synthesis of metallosalen-based microporousorganic polymer with salen-palladium building block by a bottom-up strategy.Conclusions are summarized as follows:In Chapter II, we report two novel three-connected phenoxy-imine ligands.Treatment of these ligands with3equiv of NaH, followed by reaction with ZrCl4(THF)2afforded the self-immobilized FI-Zr catalysts. These catalysts were characterized byelemental analyses, ICP-OES analyses, nitrogen sorption isotherms, solid state13Ccross-polarization magic-angle spinning (CP-MAS) NMR analysis, Powder X-raydiffraction analysis, Fourier-transform infra-red (FTIR) spectra, TGA and SEM. Theresults showed that the catalysts which prepared in THF own the highest BET areas.They are stable in nitrogen atmosphere up to200°C, as revealed by TGA. The SEMimages of the PCP catalysts show spherical-like particles with diameters of100-300nm.The PCP catalysts were investigated as catalysts for ethylene polymerization. Uponactivation with AlR3(R=Me, Et,iBu)/Ph3CB(C6F5)4, these complexes exhibit a goodcatalytic activity and long life time for ethylene polymerization, and producepolyethylene with high molecular weight and broad molecular weight distribution. Thepolyethylenes were irregular particles. In summary, the self-immobilized PCP catalystshave potential applications in industrial processes.In Chapter III, we ultilized the same method and ligand reported in Chapter II toconstruct two self-immobilized FI-Hf catalysts in PCP frame. These catalysts werecharacterized too. Upon activation with AlR3(R=Me, Et,iBu)/Ph3CB(C6F5)4, thesecomplexes exhibit a moderate catalytic activity. The polyethylenes obtained have broadmolecular weight distribution.In Chapter IV, using salen-palladium and1,3,5-triethynylbenzene as comonomers,we have synthesized a microporous organic polymer MsMOP-1by palladium-catalyzedSonogashira-Hagihara cross-coupling reactions. In an optimal condition, polymerizationreaction is carried out using a1.5M excess of the ethynyl functionslity in DMAc/TEA (1/1in volume) and Pd(PPh3)2Cl2/CuI as catalyst, MsMOP-1with the largest surfacearea554m2g-1. These catalysts were characterized by elemental analyses, ICP-OESanalyses, nitrogen sorption isotherms, solid state13C cross-polarization magic-anglespinning (CP-MAS) NMR analysis, PXRD, UV, IR, TGA, SEM, TEM and XPS.MsMOP-1is insoluble in common organic solvents and it is stable in nitrogenatmosphere up to300oC, as revealed by TGA. SEM images showed that MsMOP-1adopted flake morphology with a size of200400nm. The size distribution of thepolymer was220.2±25.0nm. TEM revealed the presence of a porous texture.MsMOP-1as heterogeneous catalysts are of distinct advantage over other known porousmaterials, they could be incorporated catalytic sites into the skeleton, thus the skeletonitself serves as the solid catalyst. The inherent pore provides spaces for thetransformation, as well as strong interaction between activated metal and frameworkprevents catalytic sites leaching. To evaluate the catalytic activity of MsMOP-1as arobust heterogeneous catalyst, we accordingly tested the different substituents and reuseability in Suzuki-Miyaura and Heck coupling reactions. MsMOP-1displayed highactivity, widely substrate adaptability and good recyclability in carbon-carbon couplingreactions. |
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