Selenophene derivatives generally exhibit excellent charge-transport properties for their narrow optical band gaps,increased intermolecular Se--Se interactions and well-aligned solid-state packing.At present,limited research has been accorded to the synthesis of selenophene derivatives,which limits the development of selenophene-based derivatives in synthetic chemistry and organic functional materials fields.In this thesis,starting from,three kinds of selneophene-based fused tri-circle building blocks were synthesized,the three building blocks were then used to develop nine kinds of diarylvinyl derivatives.Preliminary photoelectrical properties were characterized.The main work of the thesis can be divided into three parts as follows:1.Synthesis of 2,7-di?trimethylsilanyl?benzo[2,1-b:3,4-b']diselenophene?17?Starting from selenophene,through five steps reaction,namely,NBS bromination?91%?,Br/Li exchange and TMS group protection?87%?,bromine dance and CuCl2-promoted homocoupling?53%?,DMF formylation?67%?,McMurry cyclization?53%?,2,7-di?trimethylsilanyl?benzo[2,1-b:3,4-b']diselenophene?17?was synthesized in total yields of 15%.The structures of intermediates and 17 were confirmed by NMR,MS,HRMS and IR spectrum.2.Synthesis of diarylvinyl selenophene-based fused tricyclic aromatics as building blocksCompound 17 through three steps:NBS bromination?95%?,Br/Li exchange and formylation?70%?,Wittig reaction with bromo?4-octylbenzyl?triphenyl-?5-phosphane?50%?,bromo??5-octylthiophen-2-yl?methyl?triphenyl-?5-phosphane?48%?andbromo??5-octylselenophen-2-yl?methyl?triphenyl-?5-phosphane?46%?,diarylvinyl derivatives of benzo[2,1-b:3,4-b']diselenophene?1,2 and 3?were prepared.The total yields of 1,2 and 3 were 33%,32%and 30%,respectively,from 17.Startingfrom2,5-di?trimethylsilanyl?-diseleno[2,3-b:3',2'-d]selenophene?18?and2,5-di?trimethylsilanyl?-diseleno[2,3-b:3',2'-d]thiophene?19?through similar preparation procedures with 1,2and 3,diarylvinyl derivatives 4,5 and 6 of diseleno[2,3-b:3',2'-d]selenophene and 7,8 and 9 of diseleno[2,3-b:3',2'-d]thiophene were obtained in total yields of 30%,20%,25%,21%,20%and 23%,from18 and 19,respectively.The structures of intermediates and diarylvinyl selenophene-based fused tricyclic aromatics as building blocks were confirmed by NMR,MS,HRMS and IR spectrum.3.Photoelectric properties of diarylvinyl selenophene-based fused tricyclic aromatics as building blocksSpectral and cyclic voltammetry behaviors of compounds 1-9 were studied.In addition,quantum chemistry calculation was conducted to predict the energy levels and electron cloud distribution of the highest occupied molecular orbitals?HOMO?and the lowest unoccupied molecular orbitals?LUMO?orbitals for these derivatives.Results showed that the UV-vis absorption and fluorescence spectra gradually red-shifted,and the optical band-gaps gradually narrowed down with the changing of substituted groups from benzene to thiophene to selenophene.The calculated HOMO and LUMO levels are consistent with the experimental values.the UV-vis absorption and fluorescence spectra gradually blue-shifted,and the optical band-gaps gradually broaden from benzo[2,1-b:3,4-b']diselenophene,diseleno[2,3-b:3',2'-d]selenophene,to diseleno[2,3-b:3',2'-d]thiophene.Organic field-effect transistors based on 1 was fabricated and characterized,the mobility and on/off ratio are 1.7×10-33 cm2·V-1·s-1and 104,respectively. |