Design, Synthesisand Semiconducting Properties Studyof TPD Conjugated Polymers

Imide- and Amide-conjugated polymers have been intensively studied for organic optoelectronic field. As one of the imide units, thieno[3,4-c]pyrrole-4,6-dione(TPD)attracted the attention of many researchers owing to strong electron-withdrawing effect, symmetric and planar structure. Modulation of linkers between the composition groups inside a repeat unit and the interaction of atoms could result in altering of polymer properties such as the planarity, band-gap(Eg) and energy migration etc. In this thesis, a series of TPD D-A conjugated polymers were designed and synthesized to studythe influence of ’linker effect’ on their organic semiconducting properties. We are also study the influence of alkaline on the Heck reaction of compounds contained imide or amide group, such as TPD unit. The main results of this thesis are summarized as follow:①Three D-A conjugated polymers Q1,Q2 and Q3 were synthesized based on the thieno[3,4-c]pyrrole-4,6-dione(TPD) and two thiophenes units connected via vinylene or ethynylene π-spacer. Physical and chemical propertieswere studied through UV-absorption, electrochemistry and DFT calculation. OFETs devices studies reveal that Q1 and Q2 polymers possess p-type semiconducting properties, and they showed the maximum hole mobility of 2.2 × 10-3cm2 V-1s-1, 0.01cm2 V-1s-1, respectively. Q3 based OFET devices exhibit clear ambipolar semiconducting properties in air condition, with maximum hole and electron mobility of 1.2 × 10-6 cm2 V-1s-1 and 0.6 × 10-6 cm2 V-1s-1, respectively. The thin-films morphologies of three polymers were investigated through the XRD and AFM.②TPDconjugated polymers Q4 and Q5 were designed and prepared by altering the numbers of ethynylene or combining ethynylene with vinylene as linkers. Similarly, physical and chemical properties were investigated via UV-absorption, electrochemistryand DFT calculation.③In this paper, we also studied the influence of alkaline on the Heck reaction of compound contained imide or amide groups. Preparation rate was promoted with the weak alkali, such as sodium acetate. By-products were identified by analysizing MALDI-TOF mass spectra, then the reaction mechanism was proposed. Optimum reaction conditions were determined.