Synthesis And Properties Of Aza - Crown Ether And Pyrrolopyrrolidone (DPP) Modified

Metal-ligand coordination is one of the most important interactions used insupramolecular chemistry. terpyridine ligands can coordinate with many transitionmetal ions to form stable six octahedral coordination complex, and the complexes withinteresting magnetic, photophysical and electrochemical properties, so the moleculardesigning, synthetic methodologies and material properties for terpyridine ligands andtheir transition metal complexes have been attracting considerable attention.In this paper, terpyridine was modified by diaza crown ether and pyrrolopyrroldione (DPP), and the relationship between structure and property were systematicresearched by introducing different substituents, promising obtained new type ofoptical-electric functional materials, which structure can be controlled and possessexcellent comprehensive properties.(1)4’-(p-bromophenyl)-2,2’:6’,2’’-terpyridine was prepared by Kr hnke method,and coupled with4,13-diaza-18-crown-6in the presence of Pd/P(t-Bu)3catalyst, andN,N-di(4’-(p-phenyl)-2,2’:6’,2’’-terpyridine)-4,13-diaza-18-crown-6(L1) was obtainedin improved yield. And L1coordinated with zinc ions and cadmium ions, thecoordination polymer L1-Zn and L2-Cd were obtained. Their structure wascharacteried by NMR and FTIR. The optical physical properties of L1, L1-Zn andL1-Cd were investigated by UV-Vis and fluorescence spectroscopy, as the resultsshow: in CH2Cl2, the absorption peak of L1-Zn and L1-Cd showed a large red-shiftcompared to L1. In THF, the emission peak showed a obvious red-shift (ahout64nm)in the presence of Na+, but showed different degrees of blue-shift when Li+and Co2+existed; while adding Li+, Co2+and Zn2+, the THF solution of L1showed obviousfluorescence quenching phenomenon and exhibited good selectivity. In DMAc, only inthe presence of Cu2+, the absorption peak of L1-Zn appeared a red-shift. And studiedthe thermal and electrochemical properties of L1-Zn and L1-Cd, the results showedthat: the thermal stability of L1-Cd is better than L1-Zn;and the energy gap of L1-Znand L1-Cd was1.38eV and1.44eV, respectively.(2) Adopted Stille reaction,4’-(p-phenyl)-2,2’:6’,2’’-terpyridine) was modified bydiketopyrro-pyrrole dione(DPP), and synthesized ligand L2and L3using Pd(dppf)Cl2as the catalyst. L2and L3was coordinated with zinc ion and cadmium ion, formed thecorresponding polymers L2-Zn, L2-Cd and L3-Zn, L3-Cd, and the structure wascharacteried by NMR. The optical physical and electrochemical properties of L2, L3and their polmer were investigated by UV-Vis, fluorescence spectroscopy and cyclicvoltammetry curve. The result showed that the absorption of L2in acetonitrile differed from it in other solvents, and appeared obvious red-shift. In CHCl3, the absorption andemission wavelength of L2and its polmers were bigger than L3and its polmers, andthe shape of the absorption wavelength of L2and its polmers were wider than L3andits polmers, meanwhile the absorption wavelength of polwers were wider than thecorresponding monomer. According to the cyclic voltammetry curves, derived that theenergy gap of L2, L2-Zn and L2-Cd were1.41eV,1.43eV,1.47eV, respectively. Andthe energy gap of L3, L3-Zn and L3-Cd were1.24eV,1.55eV,1.50eV, respectively.