Design,Synthesis And Application Of Electrical And Thermal Responsive Transition Metal Complexes

The advancements of science and technology have brought us a great convenience.The dissemination and communication of massive data and information with each other has made our lives closer,but it has also brought information leakage issues.Therefore,the secure encryption and anti-counterfeiting of information have attracted wide attention from scientists.The photophysical properties of stimuli-responsive materials can be responded to external stimuli,such as light,electricity,force,heat and metal ions.Fluorescent signal can be directly observed,thus it is generally used for security printing and optical information encryption.This thesis is focused on the utilization of fluorescence emission color and intensity as encryption signal to design and prepare thermal sensitive Fe?III?complexes and electrical sensitive Pt?II?complexes for the achievement of information encryption and anti-counterfeiting applications.1. Design and synthesis of thermochromic materials with controllable responsive behavior based on dynamic metal-ligand coordination4-?[2,2':6',2''-terpyridin]-4'-yl?-N,N-di-p-tolylaniline?TPTA?,which shows strong fluorescence,was designed and synthesized to form non-emissive Fe-TPTA complex.By blending complex Fe-TPTA into polyethylene glycol?PEG?matrix at different mass ratio,the thermochromic luminescent films were prepared.Meanwhile,by changing the molecular weight of PEGs,thermochromic luminescent films with different response temperature were successfully construted.Finally,this Fe-TPTA/PEG film was successfully applied into information security and safety printing due to its advantages including high sensitivity,controllable response behavior and good reversibility.2. Synthesis and photophysical characterizations of Pt?II?complex with different nanomorphology and photphysical properties under electric stimuliThe platinum complex([Pt?tfmpy??CN?₂]^-Bu₄N⁺?tfmpy=2-?4-?trifluoromethyl?phenyl?pyridine?with bulky counterion was synthesized,and its self-assembly behaviour in the absence or presence of an electric field have been studied.Scanning electron microscopy?SEM?and transmission electron microscopy?TEM?images demonstrate an interesting morphological transformation from rod-like to flower-shaped nanoaggregate structures.For rod-like nanostructure,selected area electron diffraction?SAED?and powder X-ray diffraction?PXRD?analysis suggest that the Bu₄N⁺cations are squeezed between adjacent Pt?II?complex anions,forming alternating layers of two ions.In addition,SAED result suggests that the flower-shaped nanoaggregate is constructed by a layer-by-layer packing through the formation of Pt???Pt and?-?stacking interactions.Importantly,confocal fluorescence imaging shows that these two different stable assemblies possess distinct emission colors and lifetimes.This unique feature might be useful in various optoelectronic applications including data recording,anti-counterfeiting,and smart windows.