靛红并苊醌二甲酰亚胺类共轭分子的设计合成及性质研究

Design,Synthesis,and Properties of Conjuated Molecules with Isatin-Fused Acenaphthenequinone Imide Moieties

将靛红和氮杂靛红衍生物单元分别与苊醌二甲酰亚胺进行Knoevenagel缩合,开发了两个结构新型、强缺电特性的异靛青衍生物受体单元,包括靛红并苊醌二甲酰亚胺单元(A1)和氮杂靛红并苊醌二甲酰亚胺单元(A2).然后运用"双受体策略",进一步设计并合成了两个含A1和A2受体单元的A-A型二联体共轭分子(BA1和BA2),并对比研究了吡啶氮原子对共轭分子的骨架结构、吸收光谱、能级结构以及载流子迁移率的影响.研究发现:相比经典的异靛蓝受体,A1和A2受体单元拥有更低的LUMO能级(ca.-4.0 eV)和更大的骨架共轭;相比A1和A2,二联体化合物BA1和BA2不仅拥有更大的骨架共轭和更好的分子对称性,而且在整个紫外-可见光区的展现出强的光捕获能力;吡啶氮原子的引入增强了A2和BA2的骨架共平面性以及电子亲和力,有效地降低了A2和BA2的HOMO和LUMO能级值.基于BA1和BA2薄膜,制备了n-型场效应晶体管器件,其电子迁移率分别达1.64×10-3和2.52×10-3 cm2·V-1·s-1.

Two highly electron-deficient,novel isoindigo(IID)derivative acceptor units,including isatin-fused acenaphthenequinone imide(Al)and nitrogen-doped isatin-fused acenaphthenequinone imide(A2),were designed and synthesized via Knoevenagel consendation reaction.In comparison with the well-known IID unit,both A1 and A2 acceptor units exhibit reduced LUMO energy levels(ca.-4.0 eV)and extendedπ-conjugation backbone owing to the incorporation of strongly electron-withdrawing acenaphthenequinone imide.The properties observed here for both A1 and A2 are thus indicative of promising potential in the development of n-type organic semiconductors.On the basis of both A1 and A2 acceptor units,two A-A type organicπ-conjugated molecules(BA1 and BA2)were further designed and synthesized by self-coupling of two identical A1 or A2 acceptor units.The efect of pyridal nitrogen on the backbone structure,optical absorption,energy level,and carrier mobility of the as-preparedπ-conjugated molecules is studied systematically.The comparative investigation reveals that self-coupling of dual acceptor units into BA1 and BA2 not only endows them with extended conjugation backbone and enhanced molecular symmetry,but also improves their light-capturing abilities in the whole ultraviolet-visible region as relative to their parent acceptor units(A1 and A2).Moreover,the pyridal N-containing BA1 and BA2possess enhanced backbone coplanarity and electron affinity as compared to their parent units(A1 and A2),thereby leading to reduced HOMO and LUMO energy levels.Finally,n-type thin-film transistors are further fabricated by adopting both BA1 and BA2 as the active layers,affording the electron motilities of 1.64×10-3 and 2.52×10-3 cm2·V-1·s-1,respectively.