The Study Of Aggregation Of Conjugate Oligomer And Polymer And Photo-Physics Properties

For organic conjugated Oligomer and polymer, the electronic structure is deeply influenced by the aggregated structure. More and more researchers pay attention to the field of researching the connection between aggregated structure, which can be modified by some appropriate means, and electronic structure.Poly-phenylenevinylene(PPV) and the Oligomer of phenylenevinylene(DPV) has been prepared by Witting route and measured them by Uv-vis spectra and fluorescence spectra of both solution and powder. Then prepared the nano-composite DPV/MMT by In Situ Inserting, compared the fluorescence emission spectra of DPV/MMT nanocomposite with that of solution of DPV and powder of DPV. DPV molecule has been noticed the change of the aggregated structure with time in organic montmorillonite by means of X-ray diffraction, infrared spectrum and fluorescence spectra. This change causes the peak of the fluorescence emission spectra to reduce from 525nm and 493nm to 438nm and 474nm in the restricted two-dimension.In this paper, prepared and characterized the oligomer DEO-DPV (poly(2,5-diethoxy-1,4-phenylenevinylene)), derivatives of PPV, by Witting route, then prepared the nano-composite DEO-DPV/MMT by In Situ Inserting and characterized it by means of X-ray diffraction. The Fluorescence spectras of DEO-DPV and DEO-DPV/MMT indicated that the peak of fluorescence emission of the powder of DEO-DPV/MMT is consistent with that of single molecule in solution, as a result of the suppression of excimer formation because of restricted two-dimension in MMT, substituent and the twist structure.Prepared and characterized the cross-linking derivatives of PPV (LDH-PPV;HDH-PPV) by Gilch route, and investigated their photo-physics properties by means of Uv-vis and fluorescence spectra. It indicated that for PPV derivatives cross-linking by single bond, cross-linkage can increase inter-chain aggregation but suppress the intra-chain aggregation. For the emission spectra of substituted derivatives of PPV by alkoxyl, the peak at 590nm is relevant to the intra-chain aggregation of the polymer, while the peak at 630nm is relevant to the inter-chain aggregation.