DYNAMIC ORIENTATION OF CONJUGATED OLIGOMERS IN NEMATIC LIQUID-CRYSTALLINE MATRICES

Polarized photoluminescence is observed from a host/guest system consi sting of conjugated oligomers dissolved in nematic liquid crystalline matrices. In this system, conjugated oligomers (guest) exhibit an emis sion spectrum well separated from the emission of the liquid crystalli ne matrix (host) however polarized parallel to the orientation of the host matrix. The results clearly demonstrate the spontaneous orientati on of the oligothiophenes along the director of the nematic matrix. Up on applying an electric field perpendicular to the direction of the sp ontaneous orientation, the oligomers are dynamically reoriented (switc hed) with the host resulting in switching of the polarized photolumine scence.