Pi-Extended Ethynyl 21,23-Dithiaporphyrins: A Synthesis and Comparative Study of Electrochemical, Optical, and Self-Assembling Properties.

21,23-Dithiaporphyrins were synthesized containing pi-extending ethynyl substituents at the meso positions. These porphyrins displayed highly bathochromic and broadened absorbance profiles spanning 400-900 nm with molar absorptivities ranging from 2500 to 300,000 M(-1) cm(-1). Electrochemically, these ethynyl dithiaporphyrins undergo a single oxidation at 0.

Forcing aggregation of cyanine dyes with salts: a fine line between dimers and higher ordered aggregates.

It is uncommon to read about cyanine dyes in the literature and not have their aggregation discussed. They are of high interest considering their propensity to undergo self-organization in aqueous solution, leading to interesting photophysical properties resulting from the formation of their dimers and higher ordered aggregates. Currently, the study of their aggregation is in high demand due to their diverse application range including dye-sensitized solar cells.

Tuning light absorption in pyrene: synthesis and substitution effects of regioisomeric donor-acceptor chromophores.

Three isomeric donor-acceptor (DA) chromophores based on pyrene were synthesized to study the effects of substitution pattern on intramolecular charge-transfer absorption through pyrene. These chromophores are nonfluorescent and absorb light in the long-wavelength region approaching 700 nm, making them promising light-harvesters. Their optical properties depend greatly on the substitution pattern of the donor, but their electrochemical properties are relatively unaffected.