SYNTHESES OF AZOBENZENE DERIVATIVES HAVING FLUOROALKYL CHAIN AND THEIR MONOMOLECULAR FILM FORMATION AT THE AIR-WATER-INTERFACE

The compounds, 4-(nonafluorobutyl)aniline, 4-(tridecafluorohexyl)aniline, and 4-(heptadecafluorooctyl)aniline were prepared by the reaction of corresponding perfluoroalkyl iodide with 4-iodoaniline in the presence of copper bronze. Six azobenzene derivatives (4-(4-fluorophenylazo)phenol, F(C6H4)N=N(C6H4)OH (1) (C6H4-P-phenylene), 4-(4-trifluoromethylphenylazo)phenol, CF3(C6H4)N=N(C6H4)OH (2), 4-(4-heptafluoropropyl-phenylazo)phenol, C3F7(C6H4)N=N(C6H4)OH (3), 4-(4-nonafluorobutylphenylazo)phenol, C4F9(C6H4)N=N(C6H4)OH (4), 4-(4-tridecafluorohexylphenylazo)phenol, C6F13(C6H4)N=N(C6H4)OH (5), and 4-(4-heptadecafluoro-octylphenylazo)phenol, C8F17(C6H4)N=N(C6H4)OH (6)) were prepared by the usual diazo coupling reactions using 4-(perfluoroalkyl)aniline and phenol. The monomolecular film formations of the azobenzene derivatives at the air/water interface were investigated by surface pressure measurements to be dependent on the fluoroalkyl chain length(n). The compounds 5(n=6) and 6(n=8) formed stable monomolecular films at the air/water interface.