Synthesis And Recognition Of 4-Pyridone Aromatic Amide Macrocycle Molecules

The basis of biological information storage,replication and transmission is a series of molecular recognition processes occurring between nanoscale host-guest.Therefore,the study of molecular recognition is an important way to explore life phenomena at the molecular level.In the research of molecular recognition,cation recognition and neutral molecular recognition have important research and application value in many fields,such as the development of bioactive guanidinium salts,the enrichment of precious metals,and the detection of saccharide molecules.Aromatic amide structural units with a certain rigidity due to the aryl-amide bond-restricted rotation facilitate accurate design and conformational prediction to prepare aromatic amide compounds with high potential for simulating the secondary structure of biopolymers.Therefore,the study of synthesis methods and performance of aromatic amides have been widely concerned in the field of supramolecular chemistry.Based on an overview of the synthesis of aromatic amide compounds and the background of molecular recognition,this paper focuses on the use of 4-pyridone structural units that are simple in structure,easy to modify side chain groups,and can form hydrogen bond interaction and metal coordination.The aromatic amide macrocyclic molecules were constructed for the recognition of cationic or neutral molecules.1.In this paper,4-pyridonedicarboxylic acid and m-phenylenediamine derivatives were used as molecular precursors to construct aromatic amide macrocyclic compounds by a one-pot method under the influence of the intramolecular"three-center hydrogen bond"at high reaction concentrations.In terms of molecular and multi-step synthesis methods,this method has the advantages of convenient reaction operation and high efficiency of synthesis.The electronegativity and cavity size of macrocyclic molecules2-1 were regulated by deprotection and deprotonation of the O-protected phenolic hydroxyl group to prepare the anionized aromatic amide macrocyclic molecule 2-3a.The interaction between anionic 2-3a and alkali metal ions were investigated by nuclear magnetic resonance titration experiments,and the bonding strength,binding ratio and binding mode between them were systematically studied.The results show that the anionic 2-3a was bound to Cs⁺in a 1:1 manner,the binding constant was about?3.53�0.49?*10³ M^-1,and Cs⁺was bonded to two adjacent anionic O^-and one carbonyl O atom in 2-3a,respectively.Finally,combined with Gaussian theory calculation simulation and X-ray single crystal diffraction,the recognition effect of anionic 2-3a on Cs⁺was further confirmed.2.4-pyridone bis-acid was used as the precursor molecule.And the 4-pyridinone aromatic amide three-dimensional macrocyclic molecule 3-11 containing biphenyl unit was synthesized step by step via designing different strategies.The interaction of 3-11with?-D-glucopyranose,ribose and D-glucosamine,such as interaction sites and binding energies,were simulated by Gaussian theory calculation.In this paper,two kinds of aromatic amide macrocyclic molecules were prepared based on 4-pyridone structural units,and were used for recognition with alkali metal ions and natural monosaccharide molecules by means of nuclear magnetic testing,theoretical calculation optimization and single crystal structure analysis.Based on the properties of large anisotropic polarizability,high birefringence and large dipole moment of 4-pyridone structure,the use of these two types of macrocyclic molecules and their derivatives in functional materials and related fields will be explored in the future.