Synthesis Of Complex Molecular Knots Via Ferrous Ion Template

In daily life,we often discover many knots.Not only its high degree of symmetry gives us a sense of visual satisfaction,but also its practical use in daily life brings us convenience.The proteins and DNAs also have knots,which help them builds up their structural skeletons,and their topological chirality also offers them certain properties.Rrecently,researchers have used the special structure and topological chirality of molecular knots to catalyze chemical reactions.In recent years,the synthetic strategies for molecular knots have been increasingly reported,especially metal template self-assembly strategies.Although there are many methods,it is still difficult to select and synthesize ligand units and complex topological molecules.Based on this strategy,this dissertation investigates the synthesis of molecular knots by ferrous ion template:(1)Synthesis of long-chain ligands L1,L2.Synthesis of bipyridyl ligand units from 3-methylpyridine;Diphenylcyclohexane as linker,Mitsunobu coupling reaction yields long-chain h containing three bipyridyl ligand units and two linkers;The terminal position of the long-chain h is modified into alkyne,and obtain six-toothed ligand chains L1,L2,which provide raw materials for subsequent synthesis of complex molecule knots;(2)Synthesis of trefoil knot and complex topological molecules.Synthesis of opening-kont L3-Fe by three-segment with single ferrous ion template,and long-chain ligand with single ferrous ion template strategy synthesize the opening-knot L1-Fe,L2-Fe;Next,synthesis of closed-loop molecular compound 9,compound 12;The simple kinetics experiment was used to select the conditions of the click reaction.And under this condition,the opening-knot Ll-Fe and L2-Fe were closed to obtain trefoil k:not L1-Fe-12 and L2-Fe-12,complex topological molecules L1-Fe-9 and L2-Fe-9.Closed loops are created by clicking reactions,providing a way to synthesize small molecule knots and complex topological molecules.