After the first report of electroluminescence

EL

in poly(p-phenylenevinylene)(PPV)-based diodes

much effort has been devoted to the preparation of novel π-conjugated polymers in order to change the emission color and/or to increase the EL efficiency.At present the key research work for the ELDs still focus on the molecular design

synthesis and modification of luminescence materials.It is found that synthesis route

reaction conditions and raw materials used

all have strongly influence on the yield

solubility and luminescence of the product obtained.In this paper

four kinds of PPV derivatives with symmetrical and asymmetrical alkoxyl substitutes are prepared by dehydrochlorination process with

p

-methoxylphenol and

p

-diphenol as raw materials.The effects of synthesis route and reaction conditions are investigated in detailed.The molecular structure is characterized with IR

1

H-NMR and UV-Vis spectroscopy.The thermal stability and thermo performance are obtained for TGA curves.The PL and EL characteristics are examined through fluorescent spectroscopy.The results show that PMOBOPV and PMOCOPV have excellent solubility and filming forming

which are better than PDBOPV and PDCOPV.Finally a single layer and two layer light-emitting devices were fabricated with PMOBOPV as light-emitting layer and Alq

3

as electron transfer layer.The EL and PL are studied.It is indicated that for the single layer devices light-emitting voltage is 6V

the highest luminescence degree is 146cd/cm

2

;for two layer devices the luminescence voltage is 4V

the luminescence degree is 900cd/cm

2

when applied voltage become 14V.