A quantitative method based on UV-vis diffuse reflectance spectroscopy (DRS) was developed that allows determination of the fraction of monomeric and polymeric VO(x) species that are present in vanadate materials. This new quantitative method allows determination of the distribution of monomeric and polymeric surface VO(x) species present in dehydrated supported V(2)O(5)/SiO(2), V(2)O(5)/Al(2)O(3), and V(2)O(5)/ZrO(2) catalysts below monolayer surface coverage when V(2)O(5) nanoparticles are not present. Isolated surface VO(x) species are exclusively present at low surface vanadia coverage on all the dehydrated oxide supports. However, polymeric surface VO(x) species are also present on the dehydrated Al(2)O(3) and ZrO(2) supports at intermediate surface coverage and the polymeric chains are the dominant surface vanadia species at monolayer surface coverage. The propane oxidative dehydrogenation (ODH) turnover frequency (TOF) values are essentially indistinguishable for the isolated and polymeric surface VO(x) species on the same oxide support, and are also not affected by the Brønsted acidity or reducibility of the surface VO(x) species. The propane ODH TOF, however, varies by more than an order of magnitude with the specific oxide support (ZrO(2) > Al(2)O(3) >> SiO(2)) for both the isolated and polymeric surface VO(x) species. These new findings reveal that the support cation is a potent ligand that directly influences the reactivity of the bridging V-O-support bond, the catalytic active site, by controlling its basic character with the support electronegativity. These new fundamental insights about polymerization extent of surface vanadia species on SiO(2), Al(2)O(3), and ZrO(2) are also applicable to other supported vanadia catalysts (e.g., CeO(2), TiO(2), Nb(2)O(5)) as well as other supported metal oxide (e.g., CrO(3), MoO(3), WO(3)) catalyst systems.

A high‐performance organic photovoltaic cell with C70 as the sole absorber, mixed with 1,1‐bis‐(4‐bis(4‐methyl‐phenyl)‐amino‐phenyl)‐cyclohexane (TAPC), is fabricated and demonstrates a power conersion efficiency of 5.2%. With fullerene as the acceptor, high open‐circuit voltages are achieved using a donor–acceptor bulk heterojunction with a low concentration of donor in conjunction with MoOx as a Schottky barrier contact.

A diketopyrrolopyrrole-based conjugated polymer, PDPP-4FTVT, which exhibits ambipolar transport behavior in air with hole and electron mobilities up to 3.40 and 5.86 cm(2) V(-1) s(-1), respectively, is synthesized via direct arylation polycondensation. Incorporation of F-atoms in β-positions of thiophene rings dramatically improves the efficiency of direct arylation polycondensation.

UV-vis diffuse reflectance spectroscopy (DRS) and Raman spectroscopy were used to examine the electronic and molecular structures, respectively, of well-defined Mo(VI) bulk mixed oxide reference compounds ((i) isolated MoO 4 or MoO 6 monomers, (ii) dimeric O 3 Mo-O-MoO 3 , (iii) chains of alternating MoO 4 and MoO 6 units, (iv) MoO 6 -coordinated Mo 7 -Mo 12 clusters, and (v) infinite layered sheets of MoO 5 units), aqueous molybdate anions as a function of solution pH, and supported MoO 3 catalysts (MoO 3 /SiO 2 , MoO 3 /Al 2 O 3 , and MoO 3 /ZrO 2 ). Raman spectroscopy confirmed the identity and phase purity of the different bulk and solution molybdenum oxide structures. UV-vis DRS provided the corresponding electronic edge energy (Eg) of the ligand-to-metal charge transfer (LMCT) transitions of the Mo(VI) cations. A linear inverse correlation was found between Eg and the number of bridging Mo-O-Mo covalent bonds around the central Mo(VI) cation. A relationship between Eg and the domain size (N Mo ) for finite MoO x clusters, however, was not found to exist. Application of the above insights allowed for the determination of the molecular structures of the twodimensional surface MoO x species present in supported MoO 3 catalysts as a function of environmental conditions. The current electronic and molecular structural findings are critical for subsequent studies that wish to establish reliable structure-activity/selectivity relationships for molybdenum oxide catalysts, especially supported MoO 3 catalysts.

Using a "multifluorination" strategy, ambipolar donor-acceptor conjugated polymer with hole and electron mobility (μ and μ ) up to 3.94 and 3.50 cm V s , respectively, and unipolar n-type donor-acceptor conjugated polymers with μ up to 4.97 cm V s is synthesized with isoindigo as acceptor units.

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Three highly rigid and planar low-bandgap conjugated polymers comprising alternate isoindigo and dithienocarbazole groups are synthesized for the fabrication of high performance polymer solar cells. Power conversion efficiencies of up to 7.2% for conventional devices and 8.2% for inverted devices are demonstrated.

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