Synthesis And Properties Of New Functional Molecules Based On Tetrathiafulvalene And Its Derivatives

Tetrathiafulvalene (TTF) has been intensively studied due to its unique Ï€-electron donor and redox properties. TTF and its derivatives have been used as versatile building blocks in supramolecular and material chemistry. One of the research trends in new TTF derivatives for functional materials is to search for molecules with more Ï€-extended systems. It has been demonstrated that the extension of TTF core not only leads to stabilized oxidized states but also can enhance the dimensionality in materials by increasing iπ…π or S…S interactions. In this dissertation, we report the synthesis and characterization of a new coumarin functionalized tetrathiafulvalene derivative and new N-heterocycle substituted Ï€-conjugated TTF ligands and related Iridium complexes. The photophysical and electrochemical properties of all the new compounds are also discussed.1. Synthesis and properties of a new coumarin functionalized tetrathiafulvalene DerivativeA new tetrathiafulvalene (TTF) derivative possessing Schiff base core with the coumarin moiety has been synthesized and characterized. The X-ray structure of the compound has been resolved from single-crystal diffraction. The electrochemical and spectroscopic properties have also been investigated. The absorption spectral changes of L4upon addition of NOPF6have been studied. The results suggest that the oxidized compound can be obtained via chemical approach in the present system. What’s more, upon addition of HCl, the fluorescent spectrum of L4shows highly fluorescence, due to its hydrolyzation. Optimized conformation and molecular orbital diagram of L4were obtained by density functional theory (DFT). The absorption properties(Ï€â†'Ï€*and ICT) calculated by DFT, agree well with the experimental ones.2. Synthesis and properties of novel Iridium complexes based on tetrathiafulvalene ligandsTwo new pyridine conjugated ligands based on TTF (La and Lb) have been synthesized and structurally characterized by X-ray crystallography. Iridium complexes (1and2) based on the two ligands have been synthesized and characterized by elemental analysis, IR,1H NMR and MALDI-TOF-MS methods. The results of the absorption spectral changes upon addition of NOPF6of all the compounds suggest that the oxidized compounds can be obtained via chemical approach. Electrochemical studies confirmed Ï€-electron conjugated structures and interesting redox active properties for all compounds. The photoluminescence emissions of the complexes1and2indicate the phosphorescent nature of the emission.