New rigid rods amphiphilic molecules based on phenyl ethynylenes oligomers with hydrophilic side chains were synthesized by step by step method. The two most interesting products, the pentamer and the heptamer are enough amphiphilic to give stable Langmuir films that are able to be deposited as LB film on substrates as hydro-philic glass, ITO or hydrophilic silicon. A good transfer ratio of 1 is observed only by lifting, which suggests a Z type deposited film. A multilayer deposition can be carried out to 36 layers. The well structured films of 3.7 nm thick which are observed by X ray reflectivity suggest a rearragement in Y–type bilayer. By AFM, the observed irregular surface with steps of 3.7 and 1.8 nm high or multiples is coherent with a self-rearrangement of the single deposited layer to a double layer during the drying phase. The heptamer and pentamer show large stokes-shifts with a high photoluminescence emission peak at 516 and 504 nm respectively. LED properties were demonstrated using the ITO/oligoPY/ LiF-Al sandwich yielding photon emission at 516 nm for the heptamer. The electroluminescent device yields in the range of 10−3%. The demonstration of electroluminescence in a LB film of molecules aligned parallel to the substrate is very interesting because it confirms the possibility to tailor conduction and emission properties of the devices using a layer by layer deposition technique.