Tai Xishi, Yan Xihai, Wang Lihua
College of Chemistry and Chemical Engineering, Weifang University, Weifang 261061, China.
College of Biology and Oceanography, Weifang University, Weifang 261061, China.
Molecules. 2024 Feb 28;29(5):1047. doi: 10.3390/molecules29051047.
A new bis-Schiff base (L) Ca(II) complex, CaL, was synthesized by the reaction of calcium perchlorate tetrahydrate, 1,3-diamino-2-hydroxypropane, and 2-formyl phenoxyacetic acid in an ethanol-water (v:v = 2:1) solution and characterized by IR, UV-vis, TG-DTA, and X-ray single crystal diffraction analysis. The structural analysis indicates that the Ca(II) complex crystallizes in the monoclinic system, space group 12/1, and the Ca(II) ions are six-coordinated with four O atoms (O8, O9, O11, O12, or O1, O2, O4, O6) and two N atoms (N1, N2, or N3, N4) of one bis-Schiff base ligand. The Ca(II) complex forms a tetramer by intermolecular O-HO hydrogen bonds. The tetramer units further form a three-dimensional network structure by π-π stacking interactions of benzene rings. The Hirschfeld surface of the Ca(II) complex shows that the HH contacts represent the largest contribution (41.6%) to the Hirschfeld surface, followed by OH/HO and CH/HC contacts with contributions of 35.1% and 18.1%, respectively. To understand the electronic structure of the Ca(II) complex, the DFT calculations were carried out. The photocatalytic CO reduction test of the Ca(II) complex exhibited a yield of 47.9 μmol/g (CO) and a CO selectivity of 99.3% after six hours.
通过高氯酸钙四水合物、1,3 - 二氨基 - 2 - 羟基丙烷和2 - 甲酰基苯氧基乙酸在乙醇 - 水（体积比v:v = 2:1）溶液中的反应合成了一种新型双席夫碱（L）钙（II）配合物CaL，并通过红外光谱（IR）、紫外 - 可见光谱（UV - vis）、热重 - 差示热分析（TG - DTA）和X射线单晶衍射分析对其进行了表征。结构分析表明，Ca（II）配合物结晶于单斜晶系，空间群为I2/1，Ca（II）离子与一个双席夫碱配体的四个O原子（O8、O9、O11、O12或O1、O2、O4、O6）和两个N原子（N1、N2或N3、N4）形成六配位。Ca（II）配合物通过分子间O - HO氢键形成四聚体。四聚体单元通过苯环的π - π堆积相互作用进一步形成三维网络结构。Ca（II）配合物的Hirschfeld表面显示，HH接触对Hirschfeld表面的贡献最大（41.6%），其次是OH/HO和CH/HC接触，贡献分别为35.1%和18.1%。为了理解Ca（II）配合物的电子结构，进行了密度泛函理论（DFT）计算。Ca（II）配合物的光催化CO还原测试在六小时后显示出47.9 μmol/g（CO）的产率和99.3%的CO选择性。
