Ahmed Mukhtar, Malhotra Sumit Sahil, Yadav Oval, Saini Charu, Sharma Neha, Gupta Manoj Kumar, Mohapatra Ranjan Kumar, Ansari Azaj
Department of Chemistry, Central University of Haryana, Mahendergarh, 123031, India.
Life Science, Dyal Singh College, University of Delhi, Delhi, 110003, India.
J Mol Model. 2024 Apr 4;30(5):122. doi: 10.1007/s00894-024-05912-5.
In this study, we have investigated the structure, reactivity, bonding, and electronic transitions of DPA and PDTC along with their Ni-Zn complexes using DFT/TD-DFT methods. The energy gap between the frontier orbitals was computed to understand the reactivity pattern of the ligands and metal complexes. From the energies of FMO's, the global reactivity descriptors such as electron affinity, ionization potential, hardness (η), softness (S), chemical potential (μ), electronegativity (χ), and electrophilicity index (ω) have been calculated. The complexes show a strong NLO properties due to easily polarization as indicated by the narrow HOMO-LUMO gap. The polarizability and hyperpolarizabilities of the complexes indicate that they are good candidates for NLO materials. Molecular electrostatic potential (MEP) maps identified electrophilic and nucleophilic sites on the surfaces of the complexes. TDDFT and NBO analyses provided insights into electronic transitions, bonding, and stabilizing interactions within the studied complexes. DPA and PDTC exhibited larger HOMO-LUMO gaps and more negative electrostatic potentials compared to their metal complexes suggesting the higher reactivity. Ligands (DPA and PDTC) had absorption spectra in the range of 250 nm to 285 nm while their complexes spanned 250 nm to 870 nm. These bands offer valuable information on electronic transitions, charge transfer and optical behavior. This work enhances our understanding of the electronic structure and optical properties of these complexes.
Gaussian16 program was used for the optimization of all the compounds. B3LYP functional in combination with basis sets, such as LanL2DZ for Zn, Ni and Cu while 6-311G** for other atoms like C, H, O, N, and S was used. Natural bond orbital (NBO) analysis is carried out to find out how the filled orbital of one sub-system interacts with the empty orbital of another sub-system. The ORCA software is used for computing spectral features along with the zeroth order regular approximation method (ZORA) to observe its relativistic effects. TD-DFT study is carried out to calculate the excitation energy by using B3LYP functional.
在本研究中，我们使用密度泛函理论/含时密度泛函理论（DFT/TD-DFT）方法研究了二吡啶胺（DPA）和吡咯烷二硫代氨基甲酸盐（PDTC）及其镍锌配合物的结构、反应性、键合和电子跃迁。计算了前沿轨道之间的能隙，以了解配体和金属配合物的反应模式。根据前线分子轨道（FMO）的能量，计算了诸如电子亲和能、电离势、硬度（η）、软度（S）、化学势（μ）、电负性（χ）和亲电性指数（ω）等全局反应性描述符。由于 HOMO-LUMO 能隙狭窄表明易于极化，这些配合物表现出很强的非线性光学（NLO）性质。配合物的极化率和超极化率表明它们是 NLO 材料的良好候选者。分子静电势（MEP）图确定了配合物表面的亲电和亲核位点。含时密度泛函理论（TDDFT）和自然键轨道（NBO）分析为所研究配合物中的电子跃迁、键合和稳定相互作用提供了深入了解。与它们的金属配合物相比，DPA 和 PDTC 表现出更大的 HOMO-LUMO 能隙和更负的静电势，表明其反应性更高。配体（DPA 和 PDTC）在 250 nm 至 285 nm 范围内有吸收光谱，而它们的配合物的吸收光谱范围为 250 nm 至 870 nm。这些谱带提供了有关电子跃迁、电荷转移和光学行为的有价值信息。这项工作增强了我们对这些配合物的电子结构和光学性质的理解。
使用 Gaussian16 程序对所有化合物进行优化。使用 B3LYP 泛函并结合诸如用于 Zn、Ni 和 Cu 的 LanL2DZ 基组以及用于其他原子如 C、H、O、N 和 S 的 6-311G** 基组。进行自然键轨道（NBO）分析以找出一个子系统的填充轨道与另一个子系统的空轨道如何相互作用。使用 ORCA 软件结合零阶正则近似方法（ZORA）来计算光谱特征，以观察其相对论效应。使用 B3LYP 泛函进行含时密度泛函理论（TD-DFT）研究以计算激发能。
