The Effect Of Alkyl Chain Length On Solid-State Photophysical Properties Of Indene-1,3-Dionemethylene-4H-pyran/1,4-dihydropyridine Derivatives

Recent years,a series of fluorescent materials with the aggregation-induced emission(AIE)properties have attracted the attention of researchers because they break the aggregation caused quenching(ACQ)of the traditional compounds in the aggregation state and high concentration.As is known to all that the physical and chemical properties of the materials are changed by changing the molecular structure and aggregation behavior of the compounds.However,recent studies have showed that alkyl chains play an important role in the regulation of the photophysical properties of materials.Therefore,in this paper,we mainly study that the effect of alkyl chain length on solid-state photophysical properties of indene-1,3-dionemethylene-4H-pyran(IDMP)and 1,4-dihydropyridine derivatives(IDM-DHP).1.Effect of alkyl chain length on solid-state photophysical properties of IDMP and IDM-DHP derivatives.A series of D-?-A IDMP and IDM-DHP Derivatives with different length of alkyl chains on the DHP ring were synthesized to investigate the effect of alkyl chains on their fluorescence properties in the aggregated state.The fluorescence emissions show obvious blue shifts with the increase of the length of the alkyl chains.Some of these compounds exhibit obvious redshift mechanofluorochromic(MFC)emission and solvent-induced emission change.We study that the application of self-assembly and pressure sensing of these compounds.2.Effect of alkyl chain length and functional groups on solid-state photophysical properties of IDM-DHP derivatives.A series of D-?-A IDM-DHP derivatives with different length of N-alkyl chains on the DHP ring were synthesized to investigate the effect of N-alkyl chains on their fluorescence properties in the aggregated state.These compounds with highly distorted conformation show obvious aggregation-induced emission enhancement phenomena when the pyran was changed to the pyridine.It is found that these compounds exhibit outstanding reversible MFC properties and solvent-induced emission change with the increase of the length of alkyl chains.MFC properties are dependent on the length of alkyl chains,revealed by the single crystal X-ray diffraction analysis.3.Effect of steric effect on solid-state photophysical properties of IDM-DHP derivatives.In addition to studying the influence of functional groups and alkyl chains on the photoelectric properties of the compounds,we further studied the influence of the steric hindrance on the luminescence behavior of the compounds.