The crystal structures of two compounds, CuL
2 and LiNCS·HL [HL = 4′-[2-(tosylamino)benzylideneamino]-2,3-benzo-15-crown-5], have been determined from synchrotron powder diffraction data. Both compounds crystallize in the monoclinic space group P2
1/c and with one molecule in the asymmetric unit. In CuL
2 the four N atoms of two bidentate L ligands coordinate the CuII ion in a distorted tetrahedral geometry with Cu—N distances of 1.98 (5)–2.05 (5) Å, while two O atoms from two sulfoxide groups complete the distorted octahedral Cu coordination [Cu—O 2.64 (4), 2.74 (4) Å]. In LiNCS·HL, lithium is coordinated by all five ether O atoms with Li—O distances of 2.03 (3)–2.50 (3) Å and an N atom from the thiocyanate moiety [Li—N 1.98 (3) Å] in a distorted pentagonal pyramidal geometry. Preliminary potentiometric selectivity measurements for ion-selective electrodes (ISEs) based on CuL
2 and ZnL
2 demonstrated significant differences in their selectivity. In order to find a possible reason for this, theoretical calculations at the DFT (B3LYP) level were performed. These calculations used the crystal structures of CuL
2, LiNCS·HL, ZnL
2 and HL as input geometries for the minimum energy optimization in vacuo. The results indicate that in ML
2 complexes (M = Cu, Zn) the electronic structure of the metal ion determines the spatial orientation of benzo-15-crown-5 macrocycles, and their different orientation in CuL
2 and ZnL
2 results in different potentiometric selectivities of ISEs based on these compounds.
两种化合物 CuL
2 和 LiNCS-HL [HL = 4′-[2-(tosylamino)benzylideneamino]-2,3-benzo-15-crown-5]] 这两种化合物的晶体结构是通过同步辐射粉末衍射数据确定的。这两种化合物都在单斜空间群 P2
1/c,不对称单元中有一个分子。在 CuL
2 中,两个双齿 L 配体的四个 N 原子以扭曲的四面体几何形状配位 CuII 离子,Cu-N 间距为 1.98 (5)-2.05 (5) Å,而两个氧化亚砜基团的两个 O 原子完成了扭曲的八面体 Cu 配位 [Cu-O 2.64 (4), 2.74 (4) Å]。在 LiNCS-HL 中,锂由全部五个醚 O 原子配位,锂-O 间距为 2.03 (3)-2.50 (3) Å,硫氰酸盐分子中的一个 N 原子[锂-N 1.98 (3) Å]呈扭曲的五边形金字塔几何结构。基于 CuL
2 和 ZnL
2 的离子选择性电极 (ISE) 的初步电位选择性测量结果表明,它们的选择性存在明显差异。为了找到其中的可能原因,我们进行了 DFT(B3LYP)水平的理论计算。这些计算使用了 CuL
2、LiNCS-HL、ZnL
2 和 HL 的晶体结构作为输入几何图形,进行空泡中的最小能量优化。结果表明,在 ML
2 复合物(M = 铜、锌)中,金属离子的电子结构决定了苯并-15-冠-5 大环的空间取向,而它们在 CuL
2 和 ZnL
2 中的不同取向导致基于这些化合物的 ISE 具有不同的电位选择性。