报道出一种含有四个乙酰胺的芘的衍生物（如图1-3），该类化合物具有两种

A pyrene derivative containing four acetamides is reported (Figure 1-3). This type of compound has two different powder states and thus exhibits different force-induced discoloration behavior. When methanol was added to the chloroform solution of the compound, a milky white solid precipitated (phase B) in the aqueous solution. The white solid showed strong blue light emission and this discolored solid was distinguished from chloroform and other conventional organic solvents. When subjected to external pressure, the white solid turns into a yellow solid (phase G), showing green fluorescence emission; in addition, the yellow solid can be restored to phase B by heating or dissolving in chloroform, as shown in Figure 1-3e Research and analysis found that the molecules in phase B are connected by hydrogen bonding, but in phase G, the external pressure will destroy the ordered hydrogen bonding arrangement, resulting in chaotic molecular structure arrangement, inhibiting the formation of H aggregation, and promoting solid color Variety. Afterwards, the researchers designed and synthesized a series of analogs of these compounds, introduced different side chains, and studied the effect of amides and side chains on their force-induced discoloration [43]. The results show that the hydrogen bonding effect of the amide has a decisive effect on the sensitivity and repeatability of the material's mechanochromism, and excessive destruction of the hydrogen bond will make it difficult to reform the directional hydrogen bond.

报道出一种含有四个乙酰胺的芘的衍生物（如图1-3），该类化合物具有两种不同的粉末状态，从而表现出不同的力致变色行为。向该化合物的氯仿溶液中添加甲醇时，水溶液中有乳白色固体析出（B相），白色固体表现出强的蓝光发射并且这种变色固体区别于氯仿和其他常规有机溶剂。当遭受到外界的压力时，白色的固体转变成黄色的固体（G相），表现出绿色荧光发射；此外，黄色固体经过加热或者溶于氯仿的方法可以恢复至B 相，如图1-3e研究分析发现，B相中分子通过氢键连接，然而G相中，外部压力将有序的氢键排布破坏，造成分子结构排布混乱，抑制了H聚集的形成，促进固态发光颜色发生了变化。之后研究者们设计合成了一种系列该类化合物的类似物，引入不同的侧链，研究了酰胺与侧链对其力致变色的影响[43]。研究结果表明：酰胺的氢键作用对该类材料的力致变色的灵敏性与重复性具有决定性作用，同时过度的破坏氢键会导致该定向氢键难以重新形成

A derivative of pyrene containing four acetamides (as shown in Fig. 1-3) is reported. The compounds have two different powder States, thus showing different mechanochemical behaviors. When methanol was added to the chloroform solution of the compound, a milky white solid (phase B) was precipitated in the aqueous solution, and the white solid showed strong blue light emission, which was different from chloroform and other conventional organic solvents. When exposed to external pressure, the white solid changes into a yellow solid (g phase), showing green fluorescence emission; in addition, the yellow solid can be recovered to B by heating or dissolving in chloroform Phase, as shown in figure 1-3e, it is found that molecules in phase B are connected by hydrogen bonds, while in phase g, the external pressure will destroy the orderly hydrogen bond arrangement, resulting in the disorder of molecular structure arrangement, inhibiting the formation of H aggregation, and promoting the change of solid-state luminescence color. After that, the researchers designed and synthesized a series of analogues of these compounds, introduced different side chains, and studied the influence of amide and side chain on their force induced discoloration [43]. The results show that the hydrogen bond of amides plays a decisive role in the sensitivity and repeatability of the force induced discoloration of this kind of materials. At the same time, the excessive destruction of the hydrogen bond will lead to the difficulty of the formation of the directional hydrogen bond<br>