The 9-anthryltriphenylstibonium cation, [1](+), has been synthesized and used as a sensor for the toxic fluoride anion in water. This stibonium cation complexes fluoride ions to afford the corresponding fluorostiborane 1-F. This reaction, which occurs at fluoride concentrations in the parts per million range, is accompanied by a drastic fluorescence turn-on response. It is also highly selective and can be used in plain tap water or bottled water to test fluoridation levels.

The phosphorescent metalloporphyrin sensitizer PtTPTNP (TPTNP = tetraphenyltetranaphtho[2,3]porphyrin) has been successfully coupled with perylenediimide (PDI) or rubrene utilized as triplet acceptors/annihilators to upconvert 690 nm incident photons into yellow fluorescence through sensitized triplet-triplet annihilation at overall efficiencies in the 6-7% range while exhibiting exceptional photostability.

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A new synthetically facile heteroleptic ruthenium(II) sensitizer (NBu(4))[Ru(4,7-dpp)(dcbpyH)(NCS)(2)], coded as YS5, where NBu(4) is tetrabutylammonium, 4,7-dpp is 4,7-diphenyl-1,10-phenanthroline, and dcbpyH is the singly deprotonated surface anchoring derivative of 4,4'-dicarboxy-2,2'-bipyridine (dcbpyH(2)), was designed, synthesized, and incorporated into regenerative mesoscopic titania-based dye-sensitized solar cells. The sensitizer has characteristic broad, high extinction coefficient MLCT bands spanning the visible spectrum. The compound was fully characterized by 1D and 2D (1)H NMR, MALDI-TOF-MS, UV-vis, photoluminescence, Raman, IR, and electrochemistry. YS5 exhibits strong visible absorption properties with a molar extinction coefficient of 1.71 x 10(4) M(-1) cm(-1) at its 522 nm maximum. In operational liquid junction-based DSSCs under simulated AM 1.5G one-sun excitation (100 mW/cm(2)), the photovoltaic performance of YS5 compares almost equally against the current benchmark sensitizer N719 in side-by-side comparisons, producing a power conversion efficiency of 6.05% with a maximum IPCE of 65% at 540 nm. The data presented in this manuscript strongly suggest that YS5 is indeed a viable sensitizer for nanocrystalline TiO(2)-based DSSCs, seemingly poised for widespread adaptation.

Three rigid-rod Ru-bpy sensitizers with linkers made of an oligo(phenyleneethynylene) (OPE) bridge varying in length (9.6-23.3 Å) and ending with an isophthalic acid anchroing unit were bound to TiO 2 (anatase) nanoparticle films, and the photoinduced electron injection rates for all three compounds were studied by femtosecond laser spectroscopy. The sensitized films were excited at 530 nm, in the MLCT region, and the injection dynamics was probed in the 600-1000 nm range. The excited state for all three compounds (τ ∼ 2 µs in acetonitrile solution) was readily quenched upon binding to TiO 2 . All injection traces could be fitted with bi-exponential decays on a measured timescale of 130 ps. Plots of the fast or slow component of the electron injection time constants probed at 670 nm vs the spacer length yielded a very low value for the attenuation factor ( ∼ 0.04 Å -1 ). Although the dependence was weak, the length of the linker clearly resulted in slower injection rates. The weak and monotonic linker length dependence had not been observed with other rigid-rod models, demonstrating the importance of anchoring groups in the design of model compounds for electron transfer studies at the semiconductor interfaces.Ru(II)-polypyridine complexes are among the most efficient photosensitizing dyes that have been employed in nanocrystalline TiO 2 solar cells (Grätzel cells or DSSCs). 1 Photoexcitation of the Ru dyes, which are covalently bound to the TiO 2 nanoparticles surface through anchoring groups, is followed by electron injection into the conduction band of the semiconductor. The electron injection is usually an ultrafast process, complete within a few tenths of femtoseconds. 2 Because of the potential applications in the field of solar energy conversion and the fundamental interest in interfacial electron-transfer processes, the charge injection step is investigated by many groups worldwide. 2,3 To date, however, there are only a few experimental studies addressing the influence of the spacer length on the rates of electron transfer at dye-semiconductor nanoparticles interfaces. 4,5 To study this effect, we developed a variety of rigid linkers for binding dyes to the semiconductor. 5-7 Here we report the femtosecond laser spectroscopy study of electron injection for three rigid-rod Ru sensitizers with linkers varying in length, 1, 2, and 3 in Figure 1, 7,8 bound to TiO 2 thin films. Each linker is made of an oligo(phenyleneethynylene) (OPE) bridge that ends with an isophthalic acid (Ipa) unit. The two anchoring COOH groups on the Ipa unit ensure fewer degrees of freedom and surface orientations, when compared to structurally similar model dyes with one COOH group that have been described by others. 4c However, the angle at which 1-3 bind to the surface is not known, and for this reason in this study, we refer to the length of the linker (C to N) rather than to a dye-to-surface distance. The FT-IR-ATR spectra of the rods bound to TiO 2 displayed a broad carboxylate band at ∼1600 cm -1 , which is most consistent w...