A series of crystal structures of bilayer forming synthetic lipid, CnAzoCmN+Br-, was determined by the X-ray diffraction method. Two typical aggregation states were found. The J-aggregation states were observed for compounds with m=5 and the H-aggregation states were observed for compounds with m-n=2. From the relationship between chemical structures and their two-dimensional bilayer structures, factors determining the molecular packing mode within a bilayer were discussed.
