A pi-Stacked Porphyrin-Fullerene Electron Donor-Acceptor Conjugate That Features a Surprising Frozen Geometry

作者：Ciammaichella Alina; Dral Pavlo O; Clark Timothy; Tagliatesta Pietro^*; Sekita Michael; Guldi Dirk M

来源：Chemistry - A European Journal, 2012, 18(44): 14008-14016.

DOI：10.1002/chem.201202245

• density functional calculations
• electron transfer
• fullerenes
• porphyrinoids
• semiempirical calculations

A %26quot;frozen%26quot; electron donor-acceptor array that bears porphyrin and fullerene units covalently linked through the ortho position of a phenyl ring and the nitrogen of a pyrrolidine ring, respectively, is reported. Electrochemical and photophysical features suggest that the chosen linkage supports both through-space and through-bond interactions. In particular, it has been found that the porphyrin singlet excited state decays within a few pico-seconds by means of a photoinduced electron transfer to give the rapid formation of a long-lived charge-separated state. Density functional theory (DFT) calculations show HOMO and LUMO to be localized on the electron-donating porphyrin and the electron-accepting fullerene moiety, respectively, at this level of theory. More specifically, semiempirical molecular orbital (MO) configuration interaction (CI) and unrestricted natural orbital (UNO)-CI methods shed light on the nature of the charge-transfer states and emphasize the importance of the close proximity of donor and acceptor for effective electron transfer.

• 出版日期2012-10