Abstract

In the present study, we report the combined experimental and computational study along with antimicrobial screening of two tri-fluorinated chalcones from 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)ethan-1-one. The (E)-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(4-(trifluoromethyl)phenyl)prop-2-en-1-one (DBTFP-1) and (E)-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(4-(trifluoromethoxy)phenyl)prop-2-en-1-one (DBTFP-2) were synthesized by the famous Claisen-Schmidt condensation reaction. The computational investigation of optimized molecular structures, bond lengths and bond angles were performed by using density functional theory (DFT) with a B3LYP functional and 6-31G(d,p) basis set. The electronic properties were computed using Time-Dependent density functional theory (TD-DFT) with a B3LYP functional and 6-31G(d,p) basis set for the optimized geometries. The lower band gap in DBTFP-1 demonstrated the inevitable intramolecular charge transfer. The UV-Visible simulations were performed in the gas phase and dichloromethane (DCM) solvent. The experimental UV-Visible analysis was performed in DCM solvent. The first singlet excited state was attributed to the n-π* and second singlet excited state to the π -π* electronic transition. The scaled vibrational bands of titled compounds were compared with experimental observations and correct vibrational assignments were made. Various global reactivity parameters were analyzed and discussed to apprehend the chemical behavior of the synthesized chalcones. MESP and contour surfaces revealed negative potentials near the oxygen atoms and positive potentials over the hydrogen atoms. Mulliken charge study revealed that C17 and C33 are the most negative and positive carbon atoms in DBTFP-1, respectively, whereas C17 and C35 are the most negative and positive carbon atoms in DBTFP-2. The antibacterial activity was performed against P. vulgaris and S. aureus and antifungal activity against A. niger and C. albicans. The antimicrobial activity for these two compounds was correlated with LUMO and band gap energy. The magnificent antimicrobial activity of DBTFP-1 was attributed to its more stabilized LUMO and lower band gap than DBTFP-2.

摘要

在本研究中，我们报告了从 1-(2,3-dihydrobenzo[ b ][1,4]dioxin-6-yl)ethan-1-中筛选出两种三氟化查尔酮的联合实验和计算研究以及抗菌筛选。一。( E )-1-(2,3-dihydrobenzo[ b ][1,4]dioxin-6-yl)-3-(4-(trifluoromethyl)phenyl)prop-2-en-1-one (DBTFP- 1) 和 ( E )-1-(2,3-二氢苯并[ b][1,4]dioxin-6-yl)-3-(4-(trifluoromethoxy)phenyl)prop-2-en-1-one (DBTFP-2) 通过著名的 Claisen-Schmidt 缩合反应合成。通过使用具有 B3LYP 泛函和 6-31G(d,p) 基组的密度泛函理论 (DFT) 对优化的分子结构、键长和键角进行了计算研究。使用时间相关密度泛函理论 (TD-DFT) 计算电子特性，其中 B3LYP 泛函和 6-31G(d,p) 基组用于优化几何。DBTFP-1 中较低的带隙证明了不可避免的分子内电荷转移。紫外-可见光模拟在气相和二氯甲烷 (DCM) 溶剂中进行。实验性紫外-可见分析在 DCM 溶剂中进行。第一个单重激发态归因于 n-π*，第二个单重激发态归因于 π -π* 电子跃迁。将标题化合物的缩放振动带与实验观察结果进行比较，并做出正确的振动分配。对各种全局反应性参数进行了分析和讨论，以了解合成查尔酮的化学行为。MESP 和轮廓表面揭示了氧原子附近的负电势和氢原子上的正电势。Mulliken电荷研究表明，C17和C33分别是DBTFP-1中最负和最正的碳原子，而C17和C35是DBTFP-2中最负和最正的碳原子。抗菌活性是针对 将标题化合物的缩放振动带与实验观察结果进行比较，并做出正确的振动分配。对各种全局反应性参数进行了分析和讨论，以了解合成查尔酮的化学行为。MESP 和轮廓表面揭示了氧原子附近的负电势和氢原子上的正电势。Mulliken电荷研究表明，C17和C33分别是DBTFP-1中最负和最正的碳原子，而C17和C35是DBTFP-2中最负和最正的碳原子。抗菌活性是针对 将标题化合物的缩放振动带与实验观察结果进行比较，并做出正确的振动分配。对各种全局反应性参数进行了分析和讨论，以了解合成查尔酮的化学行为。MESP 和轮廓表面揭示了氧原子附近的负电势和氢原子上的正电势。Mulliken电荷研究表明，C17和C33分别是DBTFP-1中最负和最正的碳原子，而C17和C35是DBTFP-2中最负和最正的碳原子。抗菌活性是针对 对各种全局反应性参数进行了分析和讨论，以了解合成查尔酮的化学行为。MESP 和轮廓表面揭示了氧原子附近的负电势和氢原子上的正电势。Mulliken电荷研究表明，C17和C33分别是DBTFP-1中最负和最正的碳原子，而C17和C35是DBTFP-2中最负和最正的碳原子。抗菌活性是针对 对各种全局反应性参数进行了分析和讨论，以了解合成查尔酮的化学行为。MESP 和轮廓表面揭示了氧原子附近的负电势和氢原子上的正电势。Mulliken电荷研究表明，C17和C33分别是DBTFP-1中最负和最正的碳原子，而C17和C35是DBTFP-2中最负和最正的碳原子。抗菌活性是针对P. vulgaris和S. aureus以及对A. niger和C. albicans的抗真菌活性。这两种化合物的抗菌活性与 LUMO 和带隙能量相关。DBTFP-1 出色的抗菌活性归因于其比 DBTFP-2 更稳定的 LUMO 和更低的带隙。