Antibacterial polymers, recyclable palladium catalysts for coupling reactions, and catalytic conversion of cellulose into liquid fuels

This thesis is focused mainly on two areas of chemistry---polymers and catalysis. In chapter 2, I have discussed the fundamentals of the chemical structure on the antibacterial activity of the imidazolium salts and polymers. The study correlates the effect of chemical nature of the alkyl tail and the positive charge on the potency of the antibacterial compounds studied. In chapter 3, I have reported the design and synthesis of silica nanoparticles supported N-heterocyclic carbene-palladium complexes and their application in carbon-carbon coupling reactions. The catalysts are air and moisture stable and because of the large surface to volume ratio of the nanoparticles, the catalyst sites are readily accessible to the reactants. Thus, they are effective catalyst for a wide range of substrates. However, conventionally, heterogeneous catalyst preparation is a multistep process including ligand synthesis, forming ligand-metal complex and then immobilization on to a solid support. In chapter 4, I have described a simple one step synthesis of heterogeneous palladium catalyst by crosslinking commercially available poly(allylamine) with a palladium salt. This method cuts down the time and cost involved otherwise and the catalyst proved to be an efficient catalyst for a number of carbon-carbon bond forming reactions. It was also easy to separate the catalyst and reused them without losing any activity. Further, in chapter 5, a mild reaction protocol for the synthesis of ether is reported. Finally, in chapter 6, I have discussed a thermo-catalytic method for converting cellulose into liquid fuels. This method used H+ ions formed from water at high temperature to bring about the acid hydrolysis of cellulose into dehydrated hexitols and finally into liquid fuels like dimethytetrahydrofuran and other C5 and C6 compounds. As no mineral acid is used, the acid recovery and disposal is no longer an issue.