Design And Synthesis Of Trefoil Knot And Overhand Knot Molecular

Knots and catenanes not only widely exist in our daily life,but also exist in the microscopic world of the molecular.The only a few nanometer sized knot molecules of natural DNA,protein,and synthetic polymers have an unusual biological and chemical properties.For example,transfer protein knots and ascorbic acid oxidase knots have remarkable characteristics in the transmission of Fe3+ and enzyme oxidation compared with their linear analogues.topology moleculars are the most complex compounds synthesized by the chemists.Sauvage synthesized a trefoil knot firstly.Fllwing on,Solomon link,Borromean link,Pentafoil knot,and some other more complex knots have been synthesized.But,designing suitable ligands reminds a challenging.The first chapter introduced the theory,naming and research status of knot and catenane.The second chapter introduced the synthesis of a trefoil knot molecule.pyridine ligand units and links were linked by the Mitusunobu reaction to obtain a long chain ligand(9),containing three linked pyridine.and the end of this ligand modificated azides group which after were restored.the long chain ligand will be modified into a terminal alkynes(13)by an amide bond.then space shuttle into open knot molecular(19)under the abduction of metal ferrous ion.the end of azido bridged compounds connected with molecular open knot to obtain a molecular trefoil knot by the 1,3-dipolar cycloaddition reaction.the target compounds were characterized by 1H NMR,13C NMR and mass spectra.The third chapter introduced the synthesis of a overhand knot molecule.We designed a large volume of porphyrin polymer blocking group(30)and a trefoil knot with a azide blocking group(34).then connected with the as prepared open knot molecules in chapter two by 1,3-dipolar cycloaddition reaction.Finally,after removed the metal ion of the open knot,the blocking group is large enough to prevent the knot spreading out to synthesize the as designed overhand knot molecular.the target compounds were characterized by 1H NMR,13C NMR and mass spectra.