The present study explores a series of novel donor-π-acceptor (D-π-A) molecules containing 4,4′-dimethyldiphenylamine moiety as donor, 4,4′-dinitrodiphenylborane as acceptor while different π-bridges as efficient linkers between them, which comprises of ($-$HCCH$-$)_n, ($-$Ph$-$)_n and ($-$Ph ̶ HCCH$-$)_n combinations for compounds in series 1, 2 and 3, respectively. Quantum chemical computations are applied to calculate the linear polarizability (α), first (β) and second (γ) hyperpolarizabilities. A comparative analysis is performed considering an increase of NLO polarizabilities as a function of different π-linkers. Among the investigated compounds, 3c shows the largest first and second hyperpolarizabilities of 1378 × 10⁻³⁰ and 34971 × 10⁻³⁶ esu, respectively. Interestingly, an increase in NLO polarizability is observed by modifying the π-conjugated bridges and the largest NLO polarizability is observed for series 3 possessing (Ph ̶ HCCH$-$)_n π-linker which is found due to its lower transition energy and higher oscillator strengths. Furthermore, TD-DFT investigations, frontier molecular orbitals (FMOs) and electron density difference (EDD) maps analysis have shown a more efficient intramolecular charge transfer character from donor to acceptor moieties through (Ph ̶ HCCH$-$)_n π-linkers. The density of states (DOS) maps are showing explicit contributions of electronic states from different fragments of a molecular system where the partial contributions of (Ph ̶ HCCH$-$)_n π-linkers is seen significant in HOMO-LUMO orbitals of all the systems in series number 3. Thus, we believe that our study will highlight the importance of different D-π-A chromophores having variant types of π-conjugation cores as discussed in the present investigation.

本研究探索了一系列新颖的供体-π-受体（D-π-A）分子，其中包含4,4'-二甲基二苯胺部分作为供体，4,4'-二硝基二苯基硼烷作为受体，而不同的π-桥作为它们之间的有效连接体，其中包含（$-$HC CH$-$）_n（$-$博士$-$）_n和（$-$̶HC CH$-$）_n个分别对应于系列1、2和3的化合物的组合。应用量子化学计算来计算线性极化率（α），第一（β）和第二（γ）超极化率。考虑到NLO极化率随不同π接头的增加而进行比较分析。在所研究的化合物中，3c分别显示出最大的第一超极化率和第二超极化率 ，分别为1378×10 ^-30和34971×10 ^-36 esu。有趣的是，增加了NLO极化通过修改π共轭桥和最大NLO极化观察到观察到为拥有（PH̶HC系列3 CH$-$）_ñ这是由于其较低的跃迁能量和较高的振子强度发现π-接头。此外，TD-DFT调查，前沿分子轨道（FMOs）和电子密度差（EDD）映射分析已通过（PH̶11C所示从供体到受体部分的更有效的分子内电荷转移性质CH$-$）_n个π-连接子。状态密度（DOS）图显示了来自分子系统不同片段的电子态的显式贡献，其中（Ph̶HC CH$-$）_ñ π的接头被认为是在序列号3。因此所有系统的HOMO-LUMO轨道显著，我们相信，我们的研究将突出其变异类型的π共轭核心的不同的d-π-A的发色团的重要性在本次调查中讨论。