Abstract Two Schifff's bases (E)-1-benzyl-N-(4-fluorobenzylidene)piperidin-4-amine (I) and (E)-1-benzyl-N-(naphthalen-2-ylmethylene)piperidin-4-amine (II) were prepared by ZnFe2O4 catalyst assisted microwave irradiated condensation method under solvent-free conditions. Synthesised Schiff's bases (I) and (II) were crystallized by a slow evaporation technique. High-quality single crystals of (I) and (II) were developed from ethanol and therefore reasonable crystal measurements are 0.28 × 0.26 × 0.21 (I) and 0.21 × 0.25 × 0.35 mm (II) and these crystals possess orthorhombic and monoclinic crystal system with the space group of P21 and P21/c respectively. Theoretical calculations were performed utilizing DFT (B3LYP) strategy with 6-31G(d,p) because of the basis set to derive the optimized geometry, dipole moment, HOMO-LUMO energy, molecular electrostatic potential, Mulliken charge population and first-order molecular hyperpolarizality (β). Further, these Schiff's bases were characterized by elemental analysis, FT-IR, 1H & 13C NMR and HR-MS spectroscopy.

中文翻译：

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(E)-1-苄基-N-(4-氟亚苄基)哌啶-4-胺和(E)-1-苄基-N-(萘-2-基亚甲基)的无溶剂合成、光谱、晶体研究和DFT计算)哌啶-4-胺

摘要 两种希夫碱 (E)-1-benzyl-N-(4-fluorobenzylidene)piperidin-4-amine (I) 和 (E)-1-benzyl-N-(naphthalen-2-ylmethylene)piperidin-4-amine (II) 是在无溶剂条件下通过 ZnFe2O4 催化剂辅助微波辐照缩合法制备的。合成的席夫碱 (I) 和 (II) 通过缓慢蒸发技术结晶。(I) 和 (II) 的高质量单晶由乙醇开发，因此合理的晶体尺寸为 0.28 × 0.26 × 0.21 (I) 和 0.21 × 0.25 × 0.35 mm (II)，这些晶体具有斜方晶系和单斜晶系空间群分别为 P21 和 P21/c。理论计算是利用 DFT (B3LYP) 策略与 6-31G(d,p) 进行的，因为基组用于导出优化的几何形状、偶极矩、HOMO-LUMO 能量、分子静电势、Mulliken 电荷数和一级分子超极化 (β)。此外，这些席夫碱的特征在于元素分析、FT-IR、1H 和 13C NMR 和 HR-MS 光谱。