Efficient Photoinduced Charge Separation in a BODIPY–C60 Dyad

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• 作者：Alessandro Iagatti ; Lorenzo Cupellini ; Giacomo Biagiotti ; Stefano Caprasecca ; Stefano Fedeli ; Andrea Lapini ; Eleonora Ussano ; Stefano Cicchi ; Paolo Foggi ; Massimo Marcaccio ; Benedetta Mennucci ; Mariangela Di Donato
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：August 4, 2016
• 年：2016
• 卷：120
• 期：30
• 页码：16526-16536
• 全文大小：532K
• 年卷期：0
• ISSN：1932-7455

文摘

A donor–acceptor dyad composed of a BF₂-chelated dipyrromethene (BODIPY) and a C₆₀ fullerene has been newly synthesized and characterized. The two moieties are linked by direct addition of an azido substituted BODIPY on the C₆₀, producing an imino–fullerene–BODIPY adduct. The photoinduced charge transfer process in this system was studied by ultrafast transient absorption spectroscopy. Electron transfer toward the fullerene was found to occur selectively exciting both the BODIPY chromophore at 475 nm and the C₆₀ unit at 266 nm on a time scale of a few picoseconds, but the dynamics of charge separation was different in the two cases. Eletrochemical studies provided information on the redox potentials of the involved species and spectroelectrochemical measurements allowed to unambiguously assign the absorption band of the oxidized BODIPY moiety, which helped in the interpretation of the transient absorption spectra. The experimental studies were complemented by a theoretical analysis based on DFT computations of the excited state energies of the two components and their electronic couplings, which allowed identification of the charge transfer mechanism and rationalization of the different kinetic behavior observed by changing the excitation conditions.