Synthesis And Properties Of Cationic Cyclometalated Platinum(?) Complexes Containing 1,10-phenanthroline

The discovery of the phenomenon of aggregation-induced emission?AIE?points out the direction for solving the major scientific problem of"Aggregation-caused quenching?ACQ?"of the traditional luminescent materials.So far,the luminescent materials with AIE properties have shown wide application prospects in biological probes,chemical sensors and optoelectronic devices.Phosphorescent materials have more abundant light-emitting properties than fluorescent materials due to the mixture of singlet and triplet emission.Therefore,it is of great importance to develop a new type of aggregation-induced phosphorescent emission?AIPE?materials based on phosphorescent metal complexes.Among them,Pt???complexes,as a typical phosphorescent material,have attracted widespread attention because of their ability to form Pt-Pt interactions,?-?stacking and other intermolecular interactions in solution or at the solid state.1,10-Phenanthroline has been widely used for the construction of luminescent materials because of its unique conjugated system and excellent electron transport properties.At present,there are few studies on the development of cyclometalated platinum???complexes with AIPE properties using 1,10-phenanthroline as the auxiliary ligand.In this thesis,a series of cyclometalated platinum???complexes containing a 1,10-phenanthroline were designed and synthesized,which were used to clarify the relationship between the structures of the Pt???complexes and their photophysical and electrochemical properties.In addition,their luminescent properties in aqueous solution were investigated.The main research content of this paper includes the following three parts:?1?A series of 12 cyclometalated platinum???complexes Pt1-Pt12 have been designed and synthesized using 1,10-phenylpyridine as the auxiliary ligand and 2-phenylpyridine derivatives as the cyclometalating ligands.Their structures were confirmed by ¹H NMR,¹³C NMR and HRMS.?2?The photophysical and electrochemical properties of the complexes Pt1-Pt9modified with alkyl or methoxy groups at the 4-position of the phenyl ring of2-phenylpyridine were studied.And the luminescent properties of the complexes were investigated in H₂O/CH₃CN with different water contents.It was found that the introduction of methyl,ethyl,n-propyl,i-propyl,n-butyl,t-butyl,i-butyl or methoxy groups had little effect on their absorption spectra and electrochemical properties of the Pt???complexes.However,significant effects of different functional groups on the luminescent properties of the complexes were observed in H₂O/CH₃CN.The results show that all complexes Pt1-Pt9are AIPE-active.Among them,Pt2 bearing a methyl group exhibits the most outstanding AIPE properties.Transmission electron microscopy tests show that Pt1,Pt2 and Pt4aggregate into nanorods in H₂O/CH₃CN at a 90%water content.?3?The photophysical and electrochemical properties of Pt10-Pt12 modified with fluorine,chlorine and bromine atoms at 4-position of the phenyl ring of 2-phenylpyridine were studied,respectively.The luminescent properties of the complexes in H₂O/CH₃CN show that the Pt10-Pt12 are AIPE-active,and the fluorinated Pt10 demonstrates the most remarkable AIPE properties.