Synthesis Of Gelling Factors Containing Phenylbenzimidazolyl And Nile Red Groups And Their Responsiveness To CO

Carbon monoxide(CO),as one of the typical atmospheric pollutants,is known as the“silent killer”due to its colorless,odorless,explosive and highly toxic characteristics,posing a serious threat to human health and safety.At present,the detection and early warning of CO need to rely on sensors based on electrolytes and metal oxide semiconductors.These instruments are very sensitive to external conditions(such as temperature and pressure),and the use process is limited.Therefore,the main research content of this paper is to design and synthesize two types of organogels containing CO-responsive groups,and to realize the visual detection of CO through the gel phase transition or color change to achieve the effect of naked eye recognition.In this paper,A series of supramolecular gels were synthesized.First,dibenzo-30-crown-10 was used as the reaction substrate,and phenylbenzimidazole and Nile red were used as CO-responsive groups.By a long alkyl chain,dibenzo-30-crown-10 and CO-responsive groups is linked together to form the host.With the guest viologen saltand the coordination of palladium acetate,the supramolecular gel is obtained by self-assembly.The coordination was characterized by ~1H NMR and IR spectroscopy,the host and guest self-assembly were characterized by ~1H NMR titration,the compound was responsive to CO by UV and fluorescence spectroscopy,and the surface of the supramolecular gel was characterized by scanning electron microscopy.The morphology was characterized.Then,in the atmosphere of CO,the A-series supramolecular gel did not collapse,but turned black.Then,a B series of organic small molecule gels were designed to respond to CO.Based on phenyl benzimidazole as the reactive group,the gel factor B1 of Schiff base derivatives was synthesized.The long-chain gelling factor B2,which responds to CO,was synthesized by using Nile red as the reactive group.The gel test was carried out on the two compounds,and the reagents that did not form a gel were screened out.The gel factor and palladium acetate were added to the obtained solvent for heating and coordination.After cooling,a gel can be formed.B1 can coordinate with palladium acetate in DMF to form a gel,and B2 can coordinate with palladium acetate in glacial acetic acid to form a gel.The metal complex gels were characterized by infrared spectroscopy,scanning electron microscopy and rheology.In the CO environment,the B1 gel collapsed in about 7 hours,and the B2 gel collapsed in about45 minutes,realizing the purpose of visualizing the detection of CO.In conclusion,compound B2 coordinated with palladium acetate to form a gel with the best response to CO.The gel collapsed in a very short time,realizing the visualization effect,and providing a new method and means for detecting CO.