Study On Luminescent System Of BODIPY Derivatives And Transition Metal Complexes

BODIPY fluorescent dye has been developed for over twenty years and it is a new fluorescent compound that is took into account widely. It is holding a more important position among fluorescent dyes for its particular photochemical and photophysical property. For example, high fluorescence quantum yield, high molar extinction coefficient, narrow absorption and emission band, having a thick skin to solvent polarity and pH value, high photostability, etc. This paper chooses four more recent BODIPY fluorescent dyes as subject investigated which are researched systematically, specifically the paper comprises of three parts:In chapter one, we elaborate basic knowledge of fluorescence and developmental status of fluorescent dyes and research progress of fluorescent molecular probes of metal ions, In the end introduce briefly solvent effect and ETN(30)、Catalan and Kamlet-Taft parameters, respectively.In chapter two, we introduce crystallographic structures and spectrographic properties of absorption and fluorescence emission in twenty different solvents and solvent effects of three BODIPY fluorescent dyes, respectively. The structural features of three BODIPY fluorescent dyes is organized transition from nonrigid to semi-rigid and rigidness. At last, the relations and differences of properties of three BODIPY fluorescent dyes are introduced in detail:Starting from the conformationally unconstrained compound3,5-di-(2-bromo phenoxy)-4,4-difluoro-8-(4-methylphenyl)-4-bora-3a,4a-diaza-s-indacene (1), two BODIPY dyes (2and3) with increasingly rigid conformations were synthesized in outstanding total yields via palladium catalyzed intramolecular benzofuran formation. Restricted bond rotation of the phenoxy fragments leads to dyes2and3which absorb and fluoresce more intensely at longer wavelengths and have higher fluorescence quantum yields relative to the unconstrained dye1. X-ray diffraction analysis shows the progressively more extended planarity of the chromophore in line with the increasing conformational restriction in the series1�'2�'3, which explains the larger red shifts of the absorption and emission spectra.In chapter three, a novel pH and metal ion-sensitive fluorescent chemosensor-4,4-difluoro-8-(4-methylphenyl)-5-(phenylethynyl)-3-[bis(pyridin-2-ylmethyl)amino]-4-bora-3a,4a-diaza-.s-indacene (4)-based on the BODIPY platform with di-(2-picolyl)-amine as chelator has been synthesized and spectroscopically/photophysically characterized. The generalized Catalan solvent scales are the best for describing the solvent-dependent vis absorption and fluorescence emission shifts of4and indicate that solvent dipolarity is the primary factor affecting the solvent-dependent absorption and emission maxima. Complex formation with several metal ions as well as protonation is investigated in acetonitrile as solvent via spectrophotometric and fluorometric titrations. The BODIPY dye forms1:1complexes with several transition-metal (Ni2+, Cu2+, Zn2+) and heavy-metal (Cd2+, Hg2+) ions, producing large bathochromic shifts in the vis absorption and fluorescence spectra and, except for Ni2+, cation-induced fluorescence amplifications. The compound also undergoes a reversible (de)protonation reaction (pKa2.46) and shows red spectral shifts upon protonation.In chapter four, we study on synthesis、crystal structure、Photophysical Performance and electronic property of Luminescent Cu(I) Complex [Cu(DPPZ)(PPh3)2]BF4. By embedding [Cu(DPPZ)(PPh3)2]BF4into a polymer supporting matrix of PS, the emission signal is found to be sensitive towards varying oxygen concentrations, with a maximum sensitivity of3.78. We attribute this sensitivity to the large conjugation plane in DPPZ ligand which can increase the population of excited state electrons and favor the oxygen attack on [Cu(DPPZ)(PPh3)2]BF4excited state.