0000000000285467
AUTHOR
V. Bliznyuk
Structure, energy and charge transport in two-dimensional crystals of cyanine dyes
Abstract In order to develop systems with controlled energy or charge transfer across molecular dimensions it is highly desirable to build two-dimensional crystals of functional dye molecules: they can be addressed from the third dimension and the lateral intermolecular interactions can be well characterized due to a fixed and defined geometry. In an effort to study these possibilities we prepared crystals of different, negatively charged cyanine dyes, formed after adsorption from a water subphase to a positively charged monolayer. These crystals are one monolayer thick, of uniform dimensions between 10 and 100 μm (depending on nucleation conditions) and of rectangular shape. Single crystal…
Two-dimensional dye crystals with controllable optical properties
The structure, molecular ordering and optical properties of single crystals of cyanine dyes grown by adsorption from a water subphase to a positively charged lipid monolayer are discussed. These crystals are one monolayer thick, of uniform dimensions between 10 and 100μm (depending on nucleation conditions) and of rectangular shape. Single crystals were studied by transmission electron diffraction and by polarized absorption and emission spectroscopy. We show that the crystals consist of two rows of densely stacked molecules with two different orientations of the long molecular axes. This leads to two perpendicularly polarized absorption bands. The measured splitting is in accordance with r…
Miscibility of cyanine dyes in two-dimensional aggregates
Mixed aggregates of cyanine dyes at a charged lipid monolayer surface are studied by absorption spectroscopy, fluorescence microscopy and electron diffraction. We show that slight variations of the molecular structure can convert a system from being fully miscible to being immiscible, and also that the concentrations of dyes in the solution and in the crystal may deviate considerably. The different concentration in the solution and crystal was observed for a molecule where force field calculations indicated the existence of two isomers in solution and where probably only one fits into the lattice.