Gan Ping-Yao, Huang Xiao, Liu Wen-Bo, Gao Feng-Wei, Su Zhong-Min
Chongqing Research Institute, Changchun University of Science and Technology, No. 618 Liangjiang Avenue, Longxing Town, Yubei District, Chongqing City 401135, China.
School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, 7989 Weixing Road, Changchun 130012, China.
Phys Chem Chem Phys. 2024 Aug 28;26(34):22388-22394. doi: 10.1039/d3cp04595a.
The external electric field has emerged as a powerful tool for building molecular switches with excellent properties. In this work, we investigate the impact of an external electric field on the transition between lithium salt and electride-like molecule conformations in Li@corannulene. Remarkably, the distance between the Li atom and the corannulene bottom displays a sharp increase under the influence of an external electric field strength of = 110 × 10 a.u. As the external electric field strength increases, the Li atom brings about different directions of charge transfer (CT). The natural population analysis (NPA) charge and the molecular electrostatic potential (ESP) results show that the intermolecular CT occurs from the Li atom to the corannulene with the ranging from 0 to 100 × 10 a.u. Interestingly, when the external electric field reaches = 110 × 10 a.u., the CT is oriented from the corannulene to the Li atom. Moreover, electron localization function (ELF) basins are presented under an of 110 × 10 a.u., which indicates that Li@corannulene exhibits electride-like (e⋯[Li@corannulene]) molecules and lithiation salt (Li[corannulene]) under an of 0 to 100 × 10 a.u. Significantly, the differences in charge transfer also contribute to a significant improvement in hyperpolarizabilities () during the conformation transition from lithiation salt (Li[corannulene]) to electride-like (e⋯[Li@corannulene]) molecules. This study explores the potential of Li@corannulene as a promising second-order NLO material, and the external electric field provides an efficient strategy for designing and developing NLO switching devices.
外部电场已成为构建具有优异性能的分子开关的有力工具。在这项工作中，我们研究了外部电场对Li@碗烯中锂盐和类电子化物分子构象之间转变的影响。值得注意的是，在 = 110×10 a.u. 的外部电场强度影响下，锂原子与碗烯底部之间的距离急剧增加。随着外部电场强度的增加，锂原子会导致不同方向的电荷转移（CT）。自然布居分析（NPA）电荷和分子静电势（ESP）结果表明，分子间CT从锂原子转移到碗烯， 范围为0至100×10 a.u.。有趣的是，当外部电场达到 = 110×10 a.u. 时，CT方向从碗烯指向锂原子。此外，在110×10 a.u. 的 下出现了电子定域函数（ELF）盆地，这表明Li@碗烯在0至100×10 a.u. 的 下表现出类电子化物（e⋯[Li@碗烯]）分子和锂化盐（Li[碗烯]）。值得注意的是，电荷转移的差异也有助于在从锂化盐（Li[碗烯]）到类电子化物（e⋯[Li@碗烯]）分子的构象转变过程中显著提高超极化率（ ）。本研究探索了Li@碗烯作为一种有前途的二阶非线性光学材料的潜力，外部电场为设计和开发非线性光学开关器件提供了一种有效策略。
