p-Terphenyl-2,2″,5″,5‴-tetracarboxylate acid based bifunctional 1D Zinc(II) metal-organic platform for luminescent sensing and gas adsorption

Hydrothermal synthesis, structures, and catalytic performance of five coordination compounds driven by 5-aminoisophthalic acid

An amino-functionalized-dicarboxylic acid, 5-aminoisophthalic acid (H2aipa), was used as a versatile building block to synthesize a series of five novel coordination compounds under hydrothermal conditions and formulated as [Co(μ3-aipa)(2,2'-H2biim)] n (1), [Ni2(μ-aipa)2(2,2'-H2biim)2(H2O)4]·4H2O (2), {[Cd(μ3-aipa)(2,2'-H2biim)]·H2O} n (3), {[Ni(μ-aipa)(μ-bpb)]·0.5bpb·H2O} n (4), and {[Ni2(μ-aipa)(μ3-aipa)(μ-dpea)2(H2O)][Ni(μ-aipa)(μ-dpea)(H2O)]·8H2O} n (5). Three supporting ligands (2,2'-biimidazole (H2biim),1,4-bis(pyrid-4-yl)benzene (bpb), and 1,2-di(4-pyridyl)ethane (dpea)) were used in the synthesis. The structures of the studied products 1-5 vary significantly, ranging from a 0D dimer (2), 2D sheets (1, 3 and 4) to 3D + 2D interpenetrated frameworks (5). Furthermore, these compounds were evaluated as heterogeneous catalysts for the Knoevenagel reaction, achieving high product yields under optimized conditions. In addition, we also investigated various reaction parameters, substrate scope, and assessed the feasibility of catalyst recycling. This thorough investigation highlights the versatility of H2aipa as a dicarboxylate building block in the formation of functional coordination polymers.

Hydrothermal Assembly, Structural Multiplicity, and Catalytic Knoevenagel Condensation Reaction of a Series of Coordination Polymers Based on a Pyridine-Tricarboxylic Acid

A pyridine-tricarboxylic acid, 5-(3',5'-dicarboxylphenyl)nicotinic acid (H3dpna), was employed as a adjustable block to assemble a series of coordination polymers under hydrothermal conditions. The seven new coordination polymers were formulated as [Co(μ3-Hdpna)(μ-dpey)]n·nH2O (1), [Zn4.5(μ6-dpna)3(phen)3]n (2), [Co1.5(μ6-dpna)(2,2'-bipy)]n (3), [Zn1.5(μ6-dpna)(2,2'-bipy)]n (4), [Co3(μ3-dpna)2(4,4'-bipy)2(H2O)8]n·2nH2O (5),[Co(bpb)2(H2O)4]n[Co2(μ3-dpna)2(H2O)4]n·3nH2O (6), and [Mn1.5(μ6-dpna)(μ-dpea)]n (7), wherein 1,2-di(4-pyridyl)ethylene (dpey), 1,10-phenanthroline (phen), 2,2'-bipyridine(2,2'-bipy),4,4'-bipyridine(4,4'-bipy),1,4-bis(pyrid-4-yl)benzene (bpb), and 1,2-di(4-pyridyl)ethane (dpea) were employed as auxiliary ligands. The structural variation of polymers 1-7 spans the range from a 2D sheet (1-4, 6, and 7) to a 3D metal-organic framework (MOF, 5). Polymers 1-7 were investigated as heterogeneous catalysts in the Knoevenagel condensation reaction, leading to high condensation product yields (up to 100%) under optimized conditions. Various reaction conditions, substrate scope, and catalyst recycling were also researched. This work broadens the application of H3dpna as a versatile tricarboxylate block for the fabrication of functional coordination polymers.

Zinc(II) Carboxylate Coordination Polymers with Versatile Applications

This review considers the applications of Zn(II) carboxylate-based coordination polymers (Zn-CBCPs), such as sensors, catalysts, species with potential in infections and cancers treatment, as well as storage and drug-carrier materials. The nature of organic luminophores, especially both the rigid carboxylate and the ancillary N-donor bridging ligand, together with the alignment in Zn-CBCPs and their intermolecular interaction modulate the luminescence properties and allow the sensing of a variety of inorganic and organic pollutants. The ability of Zn(II) to act as a good Lewis acid allowed the involvement of Zn-CBCPs either in dye elimination from wastewater through photocatalysis or in pathogenic microorganism or tumor inhibition. In addition, the pores developed inside of the network provided the possibility for some species to store gaseous or liquid molecules, as well as to deliver some drugs for improved treatment.