Rawat Poonam, Singh Ram Niwas, Gautam Anshu, Kumar Mukesh, Singh Riya, Bharati Poonam
Department of Chemistry, University of Lucknow, Lucknow 226007, Uttar Pradesh, India.
ACS Omega. 2022 Aug 16;7(34):29571-29586. doi: 10.1021/acsomega.2c00951. eCollection 2022 Aug 30.
This paper describes spectral, non-linear optical (NLO), and biological activity variation of pyrrole hydrazones as a result of structural variation. In order to study structure-property variation, pyrrole hydrazones (, , and ) were synthesized in both solid and solution phases. The grinding solvent-free method becomes rapid, easy, convenient, useful, sustainable, and eco-friendly green synthesis as compared to the classical solution phase reactions. The structure of pyrrole hydrazones has been elucidated by microanalysis and quantum chemical calculations. The intense emission at λ 521 nm ( and ) and 617 nm () in the visible (green and orange) region with Stokes shifts at 195, 160, and 282 nm reveals that the studied compounds work as good photoluminescent materials. All compounds show strong n-π* and charge transfer (π-π*) transitions in the UV-vis region with high extinction coefficients. In the studied systems (, , and ), the orbital overlap between σ(NH-O) → σ*(NH-O) is found due to intra-molecular charge transfer. The first hyperpolarizabilities were found to be 48.83 × 10 esu for and 63.89 × 10 esu for showing variation with structure. Their high values indicate more suitability for NLO application. Incorporation and/or change in position of electron-withdrawing groups increase the β values of and compared to . The β value also increases monotonically as the polarity of the solvents increases. The red shift in N-H and C=O stretching Fourier-transform infrared bonds is due to the formation of dimers. The synthesized , , and show good antimicrobial activity and are predicted to be potential antibacterial and antifungal drugs. The has more molar refractivity (122.16 esu) than and and correlates well with the calculated binding affinity and experimental antimicrobial data.
本文描述了由于结构变化导致的吡咯腙的光谱、非线性光学（NLO）和生物活性变化。为了研究结构 - 性质变化，在固相和溶液相中合成了吡咯腙（、和）。与经典的溶液相反应相比，研磨无溶剂方法成为快速、简便、实用、可持续且环保的绿色合成方法。通过微量分析和量子化学计算阐明了吡咯腙的结构。在可见光（绿色和橙色）区域，λ 521 nm（和）以及617 nm（）处的强发射以及195、160和282 nm的斯托克斯位移表明所研究的化合物是良好的光致发光材料。所有化合物在紫外 - 可见区域均表现出强的n - π和电荷转移（π - π）跃迁，且具有高消光系数。在所研究的体系（、和）中，由于分子内电荷转移，发现了σ(NH - O) → σ*(NH - O)之间的轨道重叠。发现的第一超极化率对于为48.83×10 esu，对于为63.89×10 esu，显示出随结构的变化。它们的高值表明更适合用于NLO应用。与相比，吸电子基团的引入和/或位置变化增加了和的β值。随着溶剂极性的增加，β值也单调增加。N - H和C = O伸缩傅里叶变换红外键的红移是由于二聚体的形成。合成的、和表现出良好的抗菌活性，预计是潜在的抗菌和抗真菌药物。的摩尔折射率（122.16 esu）比和大，并且与计算的结合亲和力和实验抗菌数据相关性良好。
