Synthesis Of Tetraphenylethylene Tetracycle Tetramine Propeller

The propeller structure of tetraphenylethylene is a determinant of its aggregation-induced emission（AIE）.Because the propeller structure can result in none close?-?stacking between tetraphenylethylene molecules in the aggregation state.However,the phenyl group of tetraphenylethylene can be free to rotate,and the propeller conformation can be easily transformed into each other.In this paper,the rigid short chain was connected between the phenyl groups to fix the propeller structure of tetraphenylethylene,which was used for the study of chiral optical properties and propeller configuration resolution in a single helical direction.1.Tetrahydroxytetraphenylethenetetraaldehydewassynthesizedbythe formylation reaction of tetrahydroxy tetraphenylethene.Then cis-tetraphenylethene bicyclic tetraaldehyde was produced by the reaction of tetrahydroxy tetraphenylethene aldehyde with 1,4-bis（bromomethyl）benzene.Tetraphenylethylene tetracycle tetramine propeller was obtained by the reaction of tetrachloromethyl and p-phenylenediamine after the tetraaldehyde was converted into tetrachloromethyl.Finally,the compounds were fully characterized by ¹H-NMR、¹³C-NMR、HRMS and FT-IR.2.The compound of 7 could be separated two spirals,Peak 1 with right-handed,and Peak 2 with left-handed,both of which showed a strong CD signal.3.The tetraphenylethylene tetracycle tetramine propeller could emit fluorescence in the solution,indicating that the restriction of the rotation of benzene ring could enhance the fluorescence.When aggregated,the intensity of fluorescence would be further enhanced,indicating that tetraphenylethylene tetracycle tetramine propeller had AIE performance.4.In the acetonitrile solution and ethanol solution of tetraphenylethylene tetracycle tetramine propeller,the fluorescence intensity was determined when different ions were added.The fluorescence intensity of the trivalent Fe³⁺、Al³⁺、Cr³⁺was increased 2-4 times,and the fluorescence intensity of tetravalent Sn⁴⁺in ethanol solution was 5.1 times of the blank group,simultaneously,the other metal ions increased slightly.However,only the Cu²⁺was obviously weakened by quenching up to 40%,therefore,the bivalent Cu²⁺could be selectively determined.