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ABSTRACT: Rigid rod polyisocyanopeptides bearing phthalocyanines as pendant groups have been synthesised through CuAAC of polyisocyanopeptides containing acetylene groups with zinc(II) phthalocyanine azide. As confirmed by UV/Vis, fluorescence, and circular dichroism spectroscopies, the phthalocyanines are arranged in a helical fashion along the polymer backbone, forming the longest reported well-defined phthalocyanine assembly described to date.
ChemPlusChem. 01/2012; 77(8):700-706.
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ABSTRACT: Anchors away! Two zinc phthalocyanine photosensitizers with different phosphinic acid anchor groups were synthesized. Solar cells sensitized with these compounds have a short-circuit photocurrent density of 7.6±0.2 mA cm(-2) , an open-circuit voltage of 559±30 mV, and a fill factor of 0.76±0.03, which corresponds to an overall conversion efficiency of 3.24 % under 1 sun.
Angewandte Chemie International Edition 11/2011; 51(8):1895-8. · 13.45 Impact Factor
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ABSTRACT: The synthesis of stopcocks based on zinc phthalocyanine for selective adsorption at the channel entrances of zeolite L is reported. The introduction of either an inert SiMe₃ moiety, an imidazolium cation or a reactive isothiocyanate (NCS) group allows attachment to the channel entrances of zeolite L through van der Waals interactions, electrostatic interactions, or covalent binding, respectively. Stopcocks that rely on van-der-Waals-driven adsorption require careful selection of the solvent used for the deposition onto the zeolite surface to avoid a nonspecific distribution of the molecules. Regarding the design of photonic antenna systems, a stopcock with a cationic tail was found to be the most convenient, based on the observation that efficient energy transfer from molecules located in the zeolite nanochannels is more readily obtained than in the other cases.
Chemistry 02/2011; 17(6):1855-62. · 5.93 Impact Factor
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ABSTRACT: A supramolecular phthalocyanine-squaraine ensemble which exhibits a large coverage of the solar spectrum from 850 to 250 nm has been prepared and characterized both photophysically and in bulk heterojunction solar cells.
Chemical Communications 09/2009; · 6.17 Impact Factor
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ABSTRACT: Within the present work, two series of novel ruthenium(II) phthalocyanine (RuPc) complexes with one [RuPcCOPy-nT] or two [RuPc(Py-nT)(2)] dendritic oligothiophene (DOT) ligands in the axial positions are reported. The ability of Ru(II) for axial coordination in RuPcs allowed the attachment of the Pc through the metal site to the DOT-ligands bearing pyridine at the core position of the dendrons. These extended pyridine functionalized conjugated DOT-ligands (Py-nT) were chosen to cover the spectral window between 380 and 550 nm, where the RuPc does not exhibit a strong absorption, in order to improve the light-absorption of these complexes and hence enhance the efficiency of the corresponding solar cells. Good efficiencies of up to 1.6% have been achieved when blended together with a fullerene acceptor in solution-processed photovoltaic devices, providing by far the best phthalocyanine-based bulk heterojunction solar cells reported to-date.
Journal of the American Chemical Society 07/2009; 131(24):8669-76. · 9.91 Impact Factor
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ABSTRACT: We report the first phthalocyanine-based stopcock for selective adsorption to the channel entrances of zeolite L and realisation of a new electronic dipole moment coupling situation.
Chemical Communications 04/2008; · 6.17 Impact Factor
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ABSTRACT: In order to increase the energy efficiency of dye-sensitized solar cells beyond 10%, an improved dye needs to be developed with greater light absorption in the red and near-infrared. Many dyes have been tested for this purpose; however, no dye with significant absorption beyond 750 nm has functioned properly. We have examined a series of ruthenium phthalocyanines, a dye class with large and tunable absorption in the red. For these dyes we observe a large reduction in the output voltage of the cells relative to the benchmark dye (N719). By examination of photovoltage transients and charge density measurements, we demonstrate that this reduction in voltage is caused by a 100-fold increase in the rate constant for recombination (iodine reduction) at the TiO2/electrolyte interface. N719, however, does not seem to catalyze this reaction. By examination of the literature, we propose that catalysis of the recombination reaction may be occurring for many other classes of potentially useful dyes including porphyrins, coumarins, perylenes, cyanines, merocyanines, and azulene. This widespread ability of the dye to catalyze recombination has not been appreciated before. This finding has important implications for future work to improve the red response of dye sensitized photovoltaics.
Journal of the American Chemical Society 04/2008; 130(10):2906-7. · 9.91 Impact Factor
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Journal of the American Chemical Society 09/2007; 129(30):9250-1. · 9.91 Impact Factor
