Gautam Varsha, Mishra Mirtunjai, Thapa Khem B, Kumar Jitendra, Singh Devendra, Kumar Devesh
Department of Physics, School of Physical and Decision Science, Babasaheb Bhimrao Ambedkar University (A Central University), Lucknow, UP, 226025, India.
J Mol Model. 2023 Aug 7;29(9):274. doi: 10.1007/s00894-023-05672-8.
In this present work, we calculate the electronic, spectroscopic and nonlinear optical properties (NLO) of N-dialkyl-imidazolium hexafluorophosphate (CMIM.PF, where N = 10, 12, 14, 16, 18, 20) ionic liquid crystal molecules under the effect of alkyl chain length variation in cation moiety [CMIM] with fixed anion [PF]. CONTEXT: The majority of research on ionic liquid crystal to date has been focused on experiments, while theoretical studies on the optical properties of ionic liquid crystal have been extremely rare. Nonlinear phenomena in optical devices have attracted many researchers. Therefore, results of NLO properties may favor facile synthesis and fabrication of novel-type of materials as well as optoelectronic devices. Spectroscopic studies elucidate further insight into ionic liquid crystal behavior. The results demonstrate that variations in alkyl chain length have an impact on the conformers' electrical, spectroscopic, and NLO properties as well as their stability. The stability of ionic liquid crystal molecules increases with increase in the alkyl chain length and the energy band gap range is 6.64-6.29 eV. Understanding ionic liquid crystal's physical behavior requires an understanding of their dipole moments and NLO features, which are covered in this article. The results of NLO characteristics for all ionic liquid crystal molecules show that their first-order hyperpolarizabilities are higher than the reference molecule (urea). METHODS: The electronic (molecular energy band gap, electrostatic potential map, as well as HOMO-LUMO orbitals) and spectroscopic (IR-RAMAN, UV) properties were evaluated with the help of theoretical model at B3LYP/6-31G(d) while the NLO study has been performed using B3LYP and M06-2X with different basis sets 6-31G(d) and 6-311++G(d,p), as implemented in Gaussian09 software.
在本研究中，我们计算了在阳离子部分[CMIM]（其中N = 10、12、14、16、18、20）的烷基链长度变化且阴离子[PF]固定的情况下，N - 二烷基 - 咪唑鎓六氟磷酸盐（CMIM.PF）离子液晶分子的电子、光谱和非线性光学性质（NLO）。背景：迄今为止，大多数关于离子液晶的研究都集中在实验上，而对离子液晶光学性质的理论研究极其罕见。光学器件中的非线性现象吸引了许多研究人员。因此，NLO性质的结果可能有利于新型材料以及光电器件的简便合成和制造。光谱研究进一步阐明了离子液晶的行为。结果表明，烷基链长度的变化会影响构象体的电学、光谱和NLO性质以及它们的稳定性。离子液晶分子的稳定性随着烷基链长度的增加而增加，能带隙范围为6.64 - 6.29 eV。理解离子液晶的物理行为需要了解它们的偶极矩和NLO特征，本文对此进行了阐述。所有离子液晶分子的NLO特征结果表明，它们的一阶超极化率高于参考分子（尿素）。方法：借助理论模型在B3LYP/6 - 31G(d)水平下评估电子性质（分子能带隙、静电势图以及HOMO - LUMO轨道）和光谱性质（红外 - 拉曼光谱、紫外光谱），而NLO研究则使用B3LYP和M06 - 2X以及不同的基组6 - 31G(d)和6 - 311++G(d,p)进行，如在Gaussian09软件中实现的那样。
