Since the discovery of poly(p-phenylenevinylene)electroluminescence in 1990

much effort has been devoted to the synthesis of various conjugated polymers and to adjustment of polymer energy gap by chemical and physical methods to realize the emission in whole range of visible light.Usually

among poly(p-phenylenevinylenen)and its derivatives

there are two kinds of methods to adjust their band gap.One is that the alkyl or alkoxyl sidechain are attached main chain to adjust the energy gap.Other is that the non-conjugated chain is inserted conjugated main chain

which can limit delocated-state electron in a short range and increase the energy gap.However

while the energy gap of conjugated polymer is adjusted by the alkoxyl chain or non-conjugated chain

we find that their attachment positions of main chain are related to the energy gaps. It this paper

we research the alkoxyl chain in the different position of main-chain how to change the luminescent properties.Here

the absorbance and luminescence characteristics of three conjugated-nonconjugated multiblock copolymers(CNCMBC)and three conjugated PPV derivative were investigated.For the alkoxyl radical in the side-chains of CNCMBC can strongly offer delocated electrons to conjugated main-chains

the band gap of CNCMBC can be significantly adjusted.Moreover

when alkoxyl chain locates in different position of various CNCMBC

the absorption and luminescent spectra shift.While the vicinity of carbon atoms in mainchain of CNCMBC can slightly affect the band structure.However

when the number rang of side-chain carbon atoms in conjugated PPV derivative changes from seven to twelve

the luminescence spectra are slightly changes and aren't significantly independent of band gap.Results show that the alkoxy chains in different position of PPV derivatives have different adjustment capability of energy gap.