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Comparing photosynthetic and photovoltaic efficiencies is not a simple issue. Although both processes harvest the energy in sunlight, they operate in distinctly different ways and produce different types of products: biomass or chemical fuels in the case of natural photosynthesis and nonstored electrical current in the case of photovoltaics. In order to(More)
The synthesis and photophysical properties of butadiyne-linked chlorophyll and porphyrin dimers in toluene solution and in several self-assembled prismatic structures are described. The butadiyne linkage between the 20-positions of the macrocycles results in new electronic transitions polarized along the long axes of the dimers. These transitions greatly(More)
Combining linear Zn porphyrin trimers with orthogonally derivatized porphyrin dimers leads rapidly and spontaneously to the formation of monodisperse, torsionally constrained boxes comprising six components and a total of 16 metalloporphyrins. In situ X-ray scattering measurements confirm the formation of monodisperse assemblies of precisely the size(More)
Amorphous thin film oxygen evolving catalysts, OECs, of first-row transition metals show promise to serve as self-assembling photoanode materials in solar-driven, photoelectrochemical `artificial leaf' devices. This report demonstrates the ability to use high-energy X-ray scattering and atomic pair distribution function analysis, PDF, to resolve structure(More)
Electrochemical Deposition of Iridium-oxide Amorphous Film. Starting materials and reagents were purchased from Sigma-Aldrich and used as received. The Ir precursor ([Cp*Ir(H 2 O) 3 ]SO 4) was prepared as previously described. 1,2 The amorphous iridium oxide film was electrodeposited onto 1-cm 2 ITO (indium tin oxide) electrode from a 1.5 mM Ir precursor(More)
The structure of a cyclic self-assembled tetramer of an asymmetric meso-ethynylpyridyl-functionalized Zn(II)-porphyrin was established by solution-phase X-ray scattering and diffraction; femtosecond transient absorption and anisotropy spectroscopies were used to (a) observe rapid energy transfer (3.8 ps(-1)) between porphyrin subunits and (b) establish that(More)
Using a steric self-sorting strategy, the assembly of highly ordered and rigid supramolecular boxes possessing catalytic properties has been achieved in one step. The formation of these assemblies, comprising up to 18 porphyrin centers, was readily confirmed by solution X-ray scattering in conjunction with fluorescent spectroscopy. Size-selective and(More)
Structures of four molecular squares based on rhenium coordination chemistry have been characterized in the solution phase using pair distribution function (PDF) analyses of wide-angle X-ray scattering measured to better than 1 A spatial resolution. In this report we have focused, in particular, on a comparison of structures for pyrazine- and(More)
The Advanced Photon Source (APS) operates with a timing structure advantageous for ultrafast dynamics experiments and, as a result, X-ray time-resolved studies on the 100-picosecond timescale have flourished. The standard operating mode, 24-bunch mode, runs 6S% of the time and a hybrid singlet mode runs lS% of the time, yielding a total of 80% of beamtime(More)
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