ABSTRACT
This chapter shows that very similar aggregates of several different aromatic compounds and dyes can be generated in Langmuir-Blodgett (LB)assemblies, vesicles, and mixed aqueous-organic solutions. It suggests that the extended aggregate may be best described as a mosaic of these unit aggregates. The chapter discusses some studies of aggregate formation for a series of amphiphilic squaraine dyes and some related compounds in LB at the air-water interface and in the corresponding supported LB assemblies. It examines the photophysics of some cyanine dyes that have been previously shown to form J aggregates in supported LB films. Aggregation has been observed as a general phenomenon in a number of different media for a wide variety of aromatic compounds and dyes. Several amphiphilic squaraines have also been found to form either red or blue shifted aggregates in LB assemblies, and thus it appeared especially appealing to follow the aggregation behavior of squaraines at the air-water interface.
