Mueller Matrix Polarimetry on Cyanine Dye J -Aggregates.

Cyanine dyes are known to form H - and J -aggregates in aqueous solutions. Here we show that the cyanine dye, S0271, assembles in water into vortex induced chiral J -aggregates. The chirality of the J -aggregates depends on the directionality of the vortex. This study utilised both conventional benchtop CD spectropolarimeters and Mueller matrix polarimetry. It was found that J -aggregates have real chirality alongside linear dichroism and linear and circular birefringence. We identify the factors that are key to the formation of metastable chiral J -aggregates and propose a mechanism for their assembly.