Supporting Information cm0349708"Novel Phenyl-conjugated Oligo-ene Sensitizers for TiO 2 Solar Cells" by Kitamura, T., et al., Synthetic Procedure and Spectral Data of Oligo-ene Dyes 2-Cyano-3-(4-N,N-dimethylanilino)-trans-acrylic acid (1a): 4-Dimethylaminobenzaldehyde (1.5 g, 10 mmol), methyl cyanoacetate (1.2 g, 12 mmol), and piperadine (0.1 g, 1.2 mmol) were dissolved in 20 mL ethanol and refluxed for 2 h. After the reaction, the precipitated ester was filtered and washed with ethanol. The ester was hydrolyzed in 5% KOH ethanol by refluxing for 2 h. The reaction mixture was diluted by water and the solution pH was adjusted to 6 by adding 10% HCl at r.t. The precipitate was then filtered and washed by ethanol. The precipitate was purified by column chromatography (hexane/ethyl acetate) and the recrystallization from ethanol solution gave pure 1a as yellow powder (1.5 g, 69%).

Novel boron–dibenzopyrromethene dyes with thienyl-cyanoacrylic acid units were synthesized and characterized for application in dye-sensitized solar cells (DSSCs).

Solar energy conversion by photoelectrochemical devices is being intensively investigated as an alternative energy source instead of conventional fossil-fuel-based energy systems. Of the several different types of solar cells under development today, dye-sensitized solar cells (DSSCs) have attracted considerable interest because of their significantly high photoconversion ability and low material and production costs. [1,2] As the energy conversion efficiency (h) is calculated from the shortcircuit current density (J sc ), the open-circuit voltage (V oc ), the fill factor (FF) and the intensity of incident light (P), a simultaneous improvement of the three parameters, J sc , V oc and FF, is needed in order to improve h [Eq. (1)].Since the landmark paper on DSSCs reported by Grätzel and O'Regan appeared in 1991, [1] a number of studies have focused on enhancing the efficiency of the cells by using new materials and/or improving the device structure, which has led to significant improvements in J sc or FF. [3][4][5][6][7] However, with regard to V oc , only a slight enhancement has been accomplished so far, although it is clearly expected that an increase in V oc offers a great opportunity for a substantial enhancement of h. This is probably because of the utilization of TiO 2 electrodes and electrolytes containing iodide and triiodide (I À /I 3 À ) ions, which are considered as the best electron-transfer mediators in DSSCs. As the maximum V oc is determined by the difference between the Fermi level of the electrode under illumination and the redox potential of the electrolyte, in the case of TiO 2 electrodes and iodide-based electrolytes, V oc is definitely limited to about 0.9 V. [2,8,9] With regard to the sensitizer, Ru complex dyes exhibit the highest photoconversion efficiencies of up to 11 % under AM 1.5 irradiation (100 mW cm À2

Dye-sensitized photoelectrochemical cells (DSPECs) composed of a new near-infrared BODIPY dye D1 that is co-deposited with a ruthenium water oxidation catalyst C1 have been fabricated. The devices at pH 7.2 showed an excellent Faradaic efficiency of H production (65.8%) that was 5.4 times larger than that of a triphenylamine photosensitizer D2 and C1-coadsorbed cell.