Manafi Moghadam Maryam, Ramazani Ali, Morsali Ali, Rezayati Sobhan
The Organic Chemistry Research Laboratory (OCRL), Department of Chemistry, Faculty of Science, University of Zanjan, Zanjan 45371-38791, Iran.
The Convergent Sciences & Technologies Laboratory (CSTL), Research Institute of Modern Biological Techniques (RIMBT), University of Zanjan, Zanjan 45371-38791, Iran.
Inorg Chem. 2025 Apr 28;64(16):8016-8030. doi: 10.1021/acs.inorgchem.4c05574. Epub 2025 Apr 16.
This study explores the design and synthesis of the magnetic UiO-66-NH(Zr) functionalized with a Schiff base copper(II) complex via the postsynthesis method, forming a core-shell structure that acts as a magnetically recyclable nanocatalyst. The nanocatalyst was synthesized using an affordable and straightforward method and abbreviated as magnetic@UiO-66-NH-SB-Cu(II). For this purpose, magnetic@UiO-66-NH was synthesized by modifying FeO with tetraethyl orthosilicate, ZrCl, and 2-aminoterephthalic acid, stabilizing the core, and promoting Zr-MOF growth. The surface was functionalized with pyrrole-2-carboxaldehyde and CuCl, followed by characterization through various techniques. Using particle size distributions from transmission electron microscopy images, the average size was determined to be roughly 10-22 nm. The presence of cupric ions (Cu) within the catalyst was confirmed through X-ray photoelectron spectroscopy analysis, which distinctly revealed two peaks at 940.2 and 960.1 eV corresponding to Cu 2p and Cu 2p, respectively. The synthesized nanocatalyst exhibits improved performance in the formation of chromene-annulated heterocycles from various aromatic aldehydes and various phenols with malononitrile in ethanol under reflux conditions. The catalyst can be reused by a magnet field up to seven times with only a minimal drop in the yield of the product. Cu leaching is confirmed by inductively coupled plasma analysis to occur at a rate of 0.7 wt %.
本研究通过后合成方法探索了用席夫碱铜（II）配合物功能化的磁性UiO-66-NH(Zr)的设计与合成，形成了一种核壳结构，该结构可作为磁可回收纳米催化剂。该纳米催化剂采用一种经济且简便的方法合成，简称为磁性@UiO-66-NH-SB-Cu(II)。为此，通过用原硅酸四乙酯、ZrCl和2-氨基对苯二甲酸对FeO进行改性来合成磁性@UiO-66-NH，稳定核并促进Zr-MOF生长。表面用吡咯-2-甲醛和CuCl进行功能化，随后通过各种技术进行表征。利用透射电子显微镜图像的粒度分布，确定平均尺寸约为10-22nm。通过X射线光电子能谱分析证实了催化剂中铜离子（Cu）的存在，该分析清楚地揭示了在940.2和960.1eV处分别对应于Cu 2p和Cu 2p的两个峰。合成的纳米催化剂在回流条件下于乙醇中由各种芳香醛、各种酚与丙二腈形成色烯稠合杂环的反应中表现出改进的性能。该催化剂可以通过磁场重复使用多达七次，产物产率仅略有下降。通过电感耦合等离子体分析证实铜浸出率为0.7wt%。
