Synthesis And Properties Of Asymmetric Anionic Open-Shell Perylene Diimide Derivatives With Strong H-Bond

Open-shell organic conjugated molecular systems have unique optical,electrical,and magnetic properties,and are widely used in many frontier hot fields such as organic optoelectronics,thermoelectrics,photothermal conversion,and fluorescence bioimaging.Compared with the open-shell organic conjugated molecular systems constructed by covalent bonds,hydrogen-bonded complex systems formed by lone electrons may have new properties and applications.Limited by the varieties and syntheses of such open-shell organic conjugated hydrogen-bonded complexes,people have a limited knowledge of the structure,properties and applications of these material systems.Therefore,it will broaden the horizon and promote the development of open-shell organic conjugated molecular systems if we design to synthesize a new open-shell organic conjugated hydrogen-bonded complex system based on a simple parent and establish the correlation between structures,properties,and applications.Firstly,pentafluoroaniline with strong electron-withdrawing properties was selected as the substituent group to modify the perylene imide site,so which can be used as the precursor for the further synthesis of perylene imide radicalπ-Dimer.In the presence of primary amines,π-Dimer can form hydrogen bonds with primary amines,which increased the molecular distance ofπ-Dimer.The increase of the molecular distance made the double radical properties more obvious,so it can be used in the preparation of sensors and gas detection.The current increased by nearly 11,800 times under 1 V voltage when theπ-Dimer thin film device was placed in the 20 ppm of n-butylamine vapor.The detection limit of theπ-Dimer film device towards n-butylamine was obtained to be 209 ppb under 0.5 V.Secondly,the extra electrons of theπ-Dimer radical anion were mainly distributed on the carbonyl group of the perylene core,which can be used as a scaffold to construct an open-shell hydrogen bond complex based on oxygen atom to hydrogen atom in the carbonyl group of perylene imide.A series of asymmetric hydrogen-bonded complexes of NTFPDI,STFPDI and BTFPDI was synthesized by the strong hydrogen bonding ofπ-Dimer and primary amines.The chemical structures were determined by HRMS,NMR,FT-IR,UV-Vis and other testing methods.In addition,the electronic coupling of hydrogen bonds was affected by the environment,and hydrogen-bonded complexes were sensitive to temperature,metal ions,acids,bases,and vibrations.The essence of the change of UV-Vis spectra caused by metal ions was that the metal ions hydrolyze H~+,which made the amine group of NTFPDI protonated.The greater ability of the metal ions to hydrolyze H~+was,the stronger response to NTFPDI in DMF solution was.NTFPDI was protonated under acidic conditions and deprotonated under alkaline conditions,and had excellent recovery properties for tuning the UV-Vis spectra and solution color by acids and bases.