Synthesis Of Organic Semiconductors And Double Helicene Based On Bt-DTT

During the past several decades, thiophene-based materials have attracted significant interests due to their potential applications in organic electronics, such as organic field effect transistors(OFETs), organic solar cells(OSCs) et al. In this thesis, a series of organic functional materials for OFET based on dithieno[2,3-b:2’,3’-d]thiophene(bt-DTT) were obtained. According to the unsymmetry of bt-DTT and its different activities of 2-α and 5-α positions, several bt-DTT-based compounds including novel naphthalene cored double helience(DHNC), macrocyclic compound M1, M2, and novel double helience, a symmetric dimer of 3,3′-bis(dithieno[2,3-b:2’,3’-d]thiophene)(DHCOT-1) were designed and synthesized. The main work of this thesis can be divided into three parts as followed:1. The synthesis of organic semiconductors based on bt-DTT1) The synthesis of T1 and T2With dithieno[2,3-b:2’,3’-d]thiophene(4) as starting material, through TMS-protection, selective bromination and formylation, 2-trimethylsilanyl-dithieno[2,3-b:2’,3’-d]thiophene-5-carbaldehyde(16) was generated. Compound T1 was obtained in a total yield of 14% through Wittig reaction and TMS-deprotection from 16. Compound T2 was obtained with a total yield of 16% through McMurry reaction and TMS-deprotection from 16. All the intermidates were characterized by 1H NMR, 13 C NMR, MS, HRMS. Due to the poor solubility, T1 and T2 have been characterized by high-resolution mass spectrometry(HRMS).2) The synthesis of T3 and T4With 4 as starting material, through TMS-protection, selective bromination, bromine dance and CuCl2 promoted oxidation coupling, 5,5’-di(trimethylsilanyl)-3,3’-bis-dithieno[2,3-b:2’,3’-d]thiophene(12) was generated. Compound T3 was obtained in the total yield 6.3% through ring cyclization and TMS-deprotection from 12. Compound T4 was obtained in the total yield 4.8% through formylation and McMurry reaction, TMS-deprotection from 12. Due to the poor solubility, T3 and T4 were characterized by high-resolution mass spectrometry(HRMS).2. The synthesis of DHCOT-1 and DHNCWith 5-trimethylsilanyl-dithieno[2,3-b:2’,3’-d]thiophene(5) as starting material, through selective bromination, bromine dance and CuCl2 promoted oxidation coupling, 2,2’-di(trimethylsilanyl)-6,6’-bis-dithieno[2,3-b:2’,3’-d]thiophene(11) was generated. The CuCl2 promoted oxidation homocoupling of 11 was occurred to give a D2-symmetric dimer of 3,3′-bis(dithieno[2,3-b:2’,3’-d]thiophene)(DHCOT-1) in total yield 6.3%. Compound 2-DKT was obtained through deprotonation and quenched with N,N-dimethylcarbamyl chloride(DMC) from 11. Novel naphthalene cored double helix(DHNC) was obtained in total yield 10.4% through the intermolecular McMurry reaction from 2-DKT. All the intermidates and DHCOT-1, DHNC were characterized by 1H NMR, 13 C NMR, MS, HRMS.3. The synthesis of M1 and M2Compound 2-DKT and bullhorn-shaped ketone(KT) were obtained through deprotonation and quenched with N,N-dimethylcarbamyl chloride(DMC) from 12 by “one-pot” reaction. The excessive reduction products, compound M1 and M2, instead of the expected naphthalene cored compound were obtained through the McMurry reaction from 5-DKT. As the increase of reaction time, the yield of M1 decreased while M2 increased. This phenomenon demonstrates that M2 is the excessive reduction product from compound M1. All the intermidates were characterized by 1H NMR, 13 C NMR, MS, HRMS. Due to the poor solubility, M1 and M2 were characterized by 1H NMR, MS, HRMS.