Hydrogen-Bond-Promoted Planar Conformation, Crystallinity, and Charge Transport in Semiconducting Diazaisoindigo Derivatives
Hydrogen-Bond-Promoted Planar Conformation, Crystallinity, and Charge Transport in Semiconducting Diazaisoindigo Derivatives
复制标题
半导体二氮杂异靛蓝衍生物中氢键促进的平面构象、结晶度和电荷传输
DOI：
10.1021/acsmaterialslett.2c00179
复制
发表时间：
2022
影响因子：
11.4
通讯作者：
Fang, Lei
中科院分区：
文献类型：
--
作者：
Mu, Anthony U.;Kim, Yeon-Ju;Miranda, Octavio;Vazquez, Mariela;Strzalka, Joseph;Xu, Jie;Fang, Lei
利用分子内非共价键控制π共轭分子的构象是一种很有前途的策略，可以调整这些材料的固态分子包装和电子性能。在这里，我们报道了两个模型化合物的设计和合成，其特征是在中心重杂靛蓝单元（受体）和侧翼吲哚单元（供体）之间形成分子内氢键。计算和实验研究表明，这些氢键对共面分子构象的焓稳定作用为10kcal /mol。这些氢键的形成在熵方面也稍微有利，保证了平面构象的高温稳定性。这些化合物薄膜的热退火使其在固体状态下具有较高的结晶度和取向性，而非氢键控制只能得到非晶固体。由这些薄膜制成的场效应晶体管器件显示出高达0.270 cm2V-1s-1的空穴迁移率，而非氢键控制缺乏可测量的载流子迁移率。这项工作展示了一种有效的合成策略，将强大的分子内氢键结合到共轭π系统中，并阐明了这种氢键如何促进共轭有机材料的理想分子构象、固态包装和电子性能的机制。
Conformational control of π-conjugated molecules using intramolecular noncovalent bonds represents a promising strategy to tailor the solid-state molecular packing and electronic properties of these materials. Here, we report the design and synthesis of two model compounds featuring intramolecular hydrogen bonds formed between a center diazaisoindigo unit (the acceptor) and flanking indole units (the donor). Computational and experimental investigations show that these hydrogen bonds enthalpically stabilize the coplanar molecular conformation by >10 kcal/mol. The formation of these hydrogen bonds is also slightly favorable in terms of entropy, ensuring the high-temperature stability of the planar conformation. Thermal annealing of thin films of these compounds imparts high crystallinity and orientation in the solid state, while the non-hydrogen bond control only gave an amorphous solid. Field-effect transistor devices fabricated from these thin films exhibit hole mobilities up to 0.270 cm2V–1s–1, in contrast to the lack of measurable charge carrier mobility for the non-hydrogen bond control. This work demonstrates an efficient synthetic strategy to incorporate robust intramolecular hydrogen bonds into conjugated π-systems and elucidates the mechanism on how such hydrogen bonds promote the desired molecular conformation, solid-state packing, and electronic performances of conjugated organic materials.