(E)-N'-(3-ethoxy-4-hydroxybenzylidene)-4-fluorobenzohydrazide (3E4H4FB) single crystal was obtained by recrystallization method. Single-crystal X-ray diffraction analysis revealed the crystalline structure, packing, and molecular geometry features of the prepared crystal. The structural parameters such as bond distances and angles of 3E4H4FB crystal were discussed. The B3LYP/6-311G(d,p) level of theory was used to do optimize the structure, and the computed results reveal that the optimized geometry can perfectly replicate the crystal structure. The inter- and intramolecular hydrogen bonding interactions were also interpreted. Hirshfeld surface analysis was used to elucidate and quantify the intermolecular interactions between the molecules in the crystal structure. FTIR analysis was applied to identify the characteristic functional groups of the synthesized crystal. Natural bond orbital (NBO) and Quantum Theory of Atoms in Molecules (QTAIM) analyses of the molecule were also used to quantify interactions present in the molecule. The excitation wavelengths, oscillator strengths, and excitation energies were determined by the TD-DFT calculations and compared to the experimental wavelengths. The charge transfer within the molecule was explained by the frontier molecular orbital analysis. Nonlinear optical (NLO) properties were calculated to predict the electric dipole moment and first-order hyperpolarizability of the compound. The static third-order susceptibility value was measured by the Z-scan technique. Finally, the ecotoxicity impact of the novel NLO material was assessed towards fish, daphnia, and green algae.

(E)-N'-(3-乙氧基-4-羟基亚苄基)-4-氟苯甲酰肼(3E4H4FB)单晶通过重结晶法得到。单晶 X 射线衍射分析揭示了所制备晶体的晶体结构、堆积和分子几何特征。讨论了3E4H4FB晶体的键距和角度等结构参数。B3LYP/6-311G(d,p)理论水平用于优化结构，计算结果表明优化后的几何结构可以完美地复制晶体结构。还解释了分子间和分子内氢键相互作用。Hirshfeld 表面分析用于阐明和量化晶体结构中分子之间的分子间相互作用。FTIR 分析用于鉴定合成晶体的特征官能团。分子的自然键轨道 (NBO) 和分子中原子的量子理论 (QTAIM) 分析也用于量化分子中存在的相互作用。激发波长、振荡器强度和激发能量由 TD-DFT 计算确定并与实验波长进行比较。分子内的电荷转移可以通过前沿分子轨道分析来解释。计算非线性光学 (NLO) 特性以预测化合物的电偶极矩和一阶超极化率。静态三阶磁化率值通过 Z 扫描技术测量。最后，评估了新型 NLO 材料对鱼类、水蚤、