Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198 Moscow, Russia.
Molecules. 2021 Feb 19;26(4):1101. doi: 10.3390/molecules26041101.
The new coordination polymers (CPs) [Zn(μ-1κ:1κ-L)(HO)]·n(HO) () and [Cd(μ-1κ:2κ:3,4κ-L)(HO)]·n(HO) () are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (HL) with Zn(NO).6HO or Cd(NO).4HO, respectively. They were synthesized in a basic ethanolic medium or a DMF:HO mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound is a one dimensional linear coordination polymer, whereas presents a two dimensional network. In both compounds, the coordinating ligand (L) is twisted due to the rotation of the pyrene ring around the CH-NH bond. In compound , the Zn(II) metal ion has a tetrahedral geometry, whereas, in , the dinuclear [Cd(COO)] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer is more effective than , conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.
新的配位聚合物（CPs）[Zn(μ-1κ:1κ-L)(HO)]·n(HO)()和[Cd(μ-1κ:2κ:3,4κ-L)(HO)]·n(HO)()被报道，是通过 5-{(pyren-4-ylmethyl)amino}isophthalic 酸（HL）与 Zn(NO).6HO 或 Cd(NO).4HO 的溶剂热反应分别制备的。它们分别在碱性乙醇介质或 DMF:HO 混合物中合成。这些化合物通过单晶 X 射线衍射、FTIR 光谱、热重分析和元素分析进行了表征。单晶 X 射线衍射分析表明，化合物 是一维线性配位聚合物，而 呈现二维网络。在这两种化合物中，由于吡喃环围绕 CH-NH 键的旋转，配位配体（L）发生扭曲。在化合物 中，Zn(II)金属离子具有四面体几何形状，而在 中，双核[Cd(COO)] 部分作为次级建筑单元，Cd(II)离子具有扭曲的八面体几何形状。最近，已经探索了几种 CPs 在常规条件下进行氰硅烷化反应，但 CP 催化的微波辅助醛的氰硅烷化反应尚未得到很好的研究。因此，我们在无溶剂微波辅助条件下，使用我们合成的化合物，对不同的醛与三甲基硅氰的反应进行了测试，这些化合物作为高效的非均相催化剂。配位聚合物 比 更有效，这可能是由于 Zn(II)中心的路易斯酸度高于 Cd(II)中心，并且前者骨架中的金属中心更容易接近。我们还检查了这些配位聚合物的非均相性和可回收性，表明它们在至少经过四次回收后仍然保持活性。
