Study On Supramolecular Conductive Gel Constructed Based On Ketone Benzo-15-Crown-5-Ether

In recent years,crown ether compounds have become one of the hot spots in host-guest chemistry.Due to the size effect of cavity and metal ion radius of 15-crown-5-ether molecule,15-crown-5-ether can recognize potassium ions and form a 2:1 sandwich complex,which can be used to design and synthesize some functional molecules based on its special structure.The supramolecular conducting gel based on non-covalent interaction has many excellent properties with the excellent properties of softness,fluidity,tunable shape and response to external stimuli,supramolecular conductive gels based on non-covalent action are widely used in physical,biological,material,medical and other research fields.Based on 4-pyridone as precursor,a series of 4-pyridine ketone hydrazone benzo-15-crown-5-ether monomers(5a-d)were designed and synthesized.The experimental conditions for forming stable supramolecular gel were explored from the aspects of metal salt type,concentration and gelling solvent.In addition,the selectivity and broad-spectrum of potassium salt identified by monomer 5a-d were investigated.The experimental results showed that the monomer 5a-d can specifically identify the formation of various potassium salts and form stable supramolecular gel.The binding ratio of host guest molecules to gel was determined by XPS semi quantitative analysis and NMR titration,and the experimental results showed that monomer 5a-d can form complex 6a-d with potassium salt at 1:1 ratio.Finally,the rheological test proved that the complex 6a-d could form a stable supramolecular gel in acetonitrile.The conductivity of the prepared supramolecular gel of complex 6a-d were tested,which result was about 2 m S/cm,indicating that it has excellent conductivity.Besides,the gel was found to respond sensitively for the external environmental stimulation.Therefore,the supramolecular conducting gel prepared in this paper can be directly used as conductor material,and has great potential in the field of flexible electronic materials.The main innovative achievements of this paper are as follows: 1)The innovative method of measuring the binding ratio of host-guest molecules by conductivity is put forward,which can be applied to the research of the binding ratio of host guest molecules with conductivity in the field of supramolecular chemistry;2)After the molecular model of complex 6a-d was simulated calculated by Gaussian 09 software,it was combined with the most stable molecular configuration and imported into Multiwfn 3.7 to make the LOL-π map which was used to analyze the conjugation and π-electron transfer path in the molecule;3)Based on the theoretical results and the SEM morphology of 6a-d,the reasons for the excellent conductivity of the gels were explained at molecular level according to the three-dimensional network structure.