Materials with outstanding nonlinear optical (NLO) response exhibit excellent prospects in electrooptic devices. Thus, it is essential to find a high-performance NLO material to meet the growing demand for high-speed data transmission. In this study, theoretical investigations on the second order NLO properties of the novel expanded mislinked thia-norhexaphyrin, sulfur-free pentaphyrin, and their substituted derivatives were performed using density functional theory. Theoretical calculations display that the approximate planar structures of sulfur-free pentaphyrin embedded with two five-membered rings exhibits a remarkable NLO response and holds large dipolar contribution (ΦJ=1 = 63.5%) to the first hyperpolarizability among four parent expanded mislinked porphyrins. The static first hyperpolarizability values of these expanded porphyrins were found to range from 3490 to 14 229 au. In addition, the second order NLO response of these porphyrins has greatly improved except for minority electron-releasing- and electron-withdrawing-group substituted cases, and the static first hyperpolarizability value has increased to 47 950 au after installing the donor and acceptor groups. Unambiguous evidence reveals that expanded mislinked porphyrin can serve as a potential candidate for NLO materials.

中文翻译：

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洞察扩展的具有高二阶非线性光学响应的​​错链卟啉。

具有出色的非线性光学（NLO）响应的材料在电光器件中显示出极好的前景。因此，必须找到一种高性能的NLO材料，以满足对高速数据传输不断增长的需求。在这项研究中，使用密度泛函理论对新型扩展的错误连接的硫代-正六卟啉，无硫的五卟啉及其取代衍生物的二阶NLO性质进行了理论研究。理论计算表明，嵌有两个五元环的无硫pentaphyrin的近似平面结构表现出显着的NLO响应，并且在四个母体扩展错链卟啉中对第一个超极化性具有较大的偶极贡献（ΦJ= 1 = 63.5％）。这些膨胀的卟啉的静态第一超极化率值被发现在3490至14229au之间。此外，除了少数的电子释放基团和电子吸收基团被取代的情况外，这些卟啉的二阶NLO响应得到了极大的改善，并且在安装了供体基团和受体基团后，静态第一超极化率值已增加至47 950 au。明确的证据表明，扩大的错链卟啉可作为NLO材料的潜在候选物。