Zn(ii) metal–organic architectures from ether-bridged tetracarboxylate linkers: assembly, structural variety and catalytic features. Issue 29 (6th July 2022)

• Record Type: Journal Article
• Authors: Gu, Wen-Jun; Gu, Jin-Zhong; Kirillova, Marina V.; Kirillov, Alexander M.
• Is Part Of: CrystEngComm. Volume 24:Issue 29(2022)
• Page Start: 5297
• Page End: 5306
• Publication Date: 2022-07-06
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/d2ce00722c
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : A new series of five zinc(ii ) coordination polymers was assembled from unexplored ether-bridged tetracarboxylate linkers and fully characterized. Abstract : Semi-flexible aromatic polycarboxylic acids are gaining impetus in crystal engineering of functional coordination polymers (CPs). This work opens up the use of two ether-bridged tetracarboxylic acids, 3-(2, 5-dicarboxyphenoxy)phthalic acid (H4 dpa) and 5-(2, 5-dicarboxyphenoxy)isophthalic acid (H4 dia), as versatile and still unexplored linkers for the synthesis of new Zn(ii ) coordination polymers, formulated as [Zn(μ-H2 dpa)(bipy)(H2 O)]2 n · n H2 O (1 ), [Zn2 (μ4 -dpa)(bipy)2 (H2 O)] n (2 ), [Zn2 (μ3 -dpa)(μ-bpa)2 ] n · n H2 O (3 ), [Zn2 (μ4 -dia)(bipy)2 ] n (4 ), and [Zn2 (μ7 -dia)(py)2 ] n (5 ). These compounds were prepared via a facile hydrothermal procedure using ZnCl2, H4 dpa or H4 dia linkers, and supporting N-donor ligands (2, 2′-bipyridine, bipy; bis(4-pyridyl)amine, bpa; or pyridine, py) acting as crystallization mediators. Compounds 1–5 were fully characterized and their X-ray crystal structures were established, disclosing the metal–organic architectures that range from 1D chains (1, 2, 4 ) to 2D layers (3 ) and 3D framework (5 ). Both the structural and topological features of 1–5 were underlined, indicating their dependence on the type of linker and/or mediator of crystallization. Thermal, emission, and catalytic properties of 1–5 were also investigated. In particular, the catalytic potential of the obtained CPs in the Knoevenagel condensation of benzaldehydes with propanedinitrile was evaluated, disclosing an excellent performance of several heterogeneous catalysts with up to 99% product yields. All the CPs obtained herein are the first examples of structurally characterized coordination compounds assembled from H4 dpa and H4 dia. The present study thus opens up the application of these ligands as novel ether-bridged tetracarboxylate linkers in designing functional crystalline materials.