Synthesis And Properties Of BODIPY Derivatives And Heteronuclear Metal Complexes Based On Imidazo[1,5-a]Pyridine

The imidazo[1,5-a]pyridines are an important class of heterocyclic compounds owing to their photophysical and biological properties. They have found utility in a number of areas of research including potential applications in organic light-emitting diodes(OLED) and thin-layer field effect transistors(FET). Besides,BODIPY dyes and 3d-4f complexes as interesting optoelectronic properties and applications have been widely studied. But there are few reports on related compounds based on imidazo[1,5-a]pyridine moiety. In this thesis, we report the synthesis of BODIPY derivatives and heteronuclear metal complexes based on imidazo[1,5-a]pyridine, and their luminescent properties. The main results are summarized as follows:A series of covalently linked dyads 1-6 incorporating imidazo[1,5-a]pyridine derivatives with boron dipyrromethene(BODIPY) fragment have been synthesized by a concise procedure. Their IR, 1H, 13 C NMR, and mass spectrometry have been investigated for structural characterizations. Geometric and electronic structures as well as the lowest energy electronic transitions for dyads 1-6 have been studied by using density functional theory(DFT) and time-dependent DFT(TDDFT) calculations. With substituent groups of different electronic nature(donating or withdrawing) at the 3-position of imidazo[1,5-a]pyridine moiety, the emission maxima of dyads 1-6 cover the range of 636 to 728 nm at solid state under ambient conditions.Three new π-conjugated boron complexes based on imidazo[1,5-a]pyridine 7-9 have been synthesized and characterized by IR, 1H, 13 C NMR, and mass spectrometry. These complexes exhibit have strong luminescence both in CH2Cl2 solution and at solid state under ambient conditions. Compared with 7, the emissions of 8 and 9 are red-shifted in CH2Cl2 solution.Eight new ZnII–YIII and ZnII–LnIII heterometallic Schiff base complexes: MZn L2(NO3)3(M = Y(10), La(11), Pr(12), Nd(13), Eu(14), Gd(15), Dy(16), Er(17); L = 2-(((2-(imidazo[1,5-a]pyridin-3-yl)phenyl)imino)methyl)-6-methoxyphenol), have been rationally synthesized under solvothermal conditions and characterized by IR, elemental analyses(EA), single-crystal X-ray diffraction, and powder XRD, Furthermore, luminescence in the green region for solids 10-12 and 15-17 suggested zinc/ligand-centered emission at room temperature.