Synthesis and incorporation in Langmuir films of oligophenylenevinylene dendrimers bearing a polar head group and different dendritic poly(benzyl ether) branches

Oligophenylenevinylene (OPV) units containing a hydroxyl polar head group and different dendritic poly(benzyl ether) branches bearing aliphatic chains (n-propyl and n-dodecyl) have been synthesized. The obtained dendrimers were characterized by 1H and 13C NMR, FTIR and absorption spectroscopies. Optical properties of the dendrimers have been studied in toluene and dichloromethane solutions. Changes in the maximum absorption wavelength were observed for the dendrimers OPV core. Increasing the dendron branches generation gave rise to a hypsochromic shift of the maximum absorption band of the OPV core. The ability of all dendrimers to form Langmuir films at the air–water interface was also investigated; the obtained films were characterized by surface pressure versus molecular area isotherms, and by compression–expansion cycles (hysteresis curves). All dendrimers were able to form stable Langmuir monolayers in the air–water interface, and exhibited a good reversible behavior upon successive compression/expansion cycles. The terminal alkyl chains length of the dendritic branches has a remarkable influence on the packing of highest generation dendrimers in the monolayers. These dendrimers can be promising prospects for the preparation of Langmuir–Blodgett films, in view of optical and electronic potential applications.