Six peripherally meso-modified Zn (II) porphyrin sensitizer dyes are designed and their J-V performance in dye sensitized solar cell (DSSC) evaluated. Electron-donating groups including phenothiazine, carbazole and pyrene are used to modify the porphyrin macrocycle at the meso-carbon position(s). To compare the effect of donor substitution on the performance of the cells in terms of short circuit current (Jsc), light harvesting efficiency (LHE) and power conversion efficiency (η), two sets of sensitizers with different degrees of substitution are synthesized. One set of dyes (mono-substituted) have one electron donor at trans-position to the acceptor, while the second set (tri-substituted) dyes have three of the same type electron donor groups at 5, 10 and 15 meso-carbon positions making all the six dyes push-pull type sensitizers incorporating 4'-carboxyphenyl as an electron-acceptor/anchor group. Different spectroscopic and electrochemical methods are used to study the photophysical and electrochemical properties of the dyes, while the photovoltaic performance of their cells under 1.5 A.M is studied using solar simulator. Meso-substitution of Zinc (II) porphyrin with these small donor molecules is shown to improve the light harvesting character of the Zinc (II) porphyrin macrocycle in the UV-Vis absorption while at same time improving its fluorescence quantum yield, excited-state life …

In the development of covalent organic frameworks (COFs), often the scaffold linkers are assumed to be electro- and photoinactive, and this was also to be the case for 2,3,6,7,10,11-hexahydroxytriphenylene, a tritopic linker. However, as demonstrated in the present study, the reaction product of this linker, hexaoxatriphenylene, is electron rich and when connected to a suitable photosensitizer engages itself in an efficient excited-state charge separation process. In the present study, we have employed BF2-chelated dipyrromethenes (BODIPYs) as sensitizers, which are connected to hexaoxatriphenylene through the center boron, rendering paddle-wheel-type structures. Systematic photophysical, electrochemical, computational, and photochemical studies involving pump-probe femtosecond transient spectroscopy have been performed to establish efficient charge separation in these novel supramolecular structures.

An investigation of luminescent sensing has been presented. Neutral Red, a common pH luminescent sensor, was shown to be an effective carbon dioxide sensor for the first time. Sensing experiments were performed both through fluorometric and fluorescent microscopy studies, giving rise to the possibility of carbon dioxide sensing for biological applications. Neutral Red was benchmarked against the well-established carbon dioxide sensor Pyranine (8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt), HPTS. Neutral Red was shown to have improved response times and higher consistency within the sensing drift compared to HPTS. Trinuclear Au(I) complexes have previously shown to sense metal ions through changes in their luminescent properties. A computational study on d10-d10 interactions, which exist in complexes where Cu+, Ag+, and Au+ are intercalated with [Au(μ-C2,N3-ethylImidazolate)]3 in the form of both half and full sandwich adducts. Binding energies, total density plots, and Morse and Dunham analyses of potential energy surfaces are employed to better understand the metal-metal interactions and the effects of electron correlation, basis set superposition error, and dispersion of metallophilic interactions of the adduct complexes. As metal-metal interactions within these types of complexes become better understood, the tuning of trinuclear Au(I) complexes for luminescent sensing of metals becomes increasingly possible.