Small Molecules Of Iridium Complexes Synthesis And Application Research

Phosphorescent heavy-metal complexes, such as Rh, Pt, Ir, Os,have gained growing attention due to their excellent photophysicalproperties. Iridium complexes exhibit new possibilities for applications,such as catalysis, OLED, phosphorescent chemical sensor, andbiomarker for photo stability, easily tuned emission wavelength, largeStokes shifts and long lifetimes. In this thesis, we designed andsynthesized three functionalized iridium complexes and explore theirapplications in multicolor emission and chemosensor.The details were shown as follows:1.Synthesis and Properties of nanoscale coordination polymers(NCPs)Designed and synthesized two carboxyl-functionalized iridiumcomplexes (λem=485nm and λem=600nm). We introduce yttriumions as connecting nodes by the interaction between the carboxylicacid groups with metal ions, and prepared nanoscale phosphorescentcoordination polymers. In the single-wavelength excitation with theyttrium-ion-mediated energy transfer, the tunable emissions from blueto orange multicolor phosphorescence, and even nearly white emissionwere achieved by changing doping ratio of two iridium carboxylic acidcomplexes with different emission.2.Neutral iridium phosphorescence complexes and its applicationin silver ion detectionA neutral iridium complexes Ir(dfppy)2PyCl was designed andsynthesized, and it has a bright blue-green phosphorescent emissioncentred at476nm. With dropwise addition of Ag+to the acetonitrilesolution of iridium complexes, the maximum emission peak intensity ofthe phosphorescent emission spectra was gradually reduced, theabsorbance of UV-visible absorption spectra in the ultraviolet and visible light region gradually weaken, and appear new weakabsorption peaks in the vicinity of242nm and310nm. Furtherexperimental results showed that the complexes have high selectivityfor Ag~+. According to the HR-MS data, we speculated the possiblerecognition mechanism. After adding Ag+to the acetonitrile solution ofcomplexes Ir(dfppy)2PyCl, the AgCl inorganic salt was formed by theinteraction of Cl and Ag~+, accompanied with the reduce of thephosphorescence intensity, which resulted in the effective detection forAg~+.