Exploration of Structural Topologies in Metal–Organic Frameworks Based on 3-(4-Carboxyphenyl)propionic Acid, Their Synthesis, Sorption, and Luminescent Property Studies

Abstract

Four new compounds (two coordination polymers (CPs) and two metal organic frameworks (MOFs)), namely, [Zn(cpp) 4), have been synthesized through the slow diffusion technique using cpp ligand and different neutral linkers (H 2 cpp = 3-(4-carboxyphenyl)propionic acid, 4-bpmh = N,N-bis-pyridin-4-ylmethylene-hydrazine, 3bpmh = N,N-bis-pyridin-3-ylmethylene-hydrazine, bpy = 4,4bipyridine). Single crystal X-ray analysis of compounds 1−4 reveals their structural diversities which might have been generated due to both rigidity (aryl carboxylate) and flexibility (aliphatic carboxylates) of cpp ligands as well their bridging modes and the orientation of nitrogen atoms of the neutral linkers. In addition, the dihedral angle in the aliphatic carboxylates of cpp ligand is also playing an important role in directing the final structural arrangement. Compound 1 exhibits a uninodal 6connected three-dimensional (3D) coordination polymer with point Schalfli symbol {3 3 .5 9 .6 3 } and shows an uncommon lcy; 6/ 3/c1 topological type. Compound 2 reveals a 6-connected uninodal 3D framework with point Schalfli symbol {4 8 .6 6 .8} and shows a rare rob topology. Compound 3 formed a 4-connected uninodal two-dimensional framework with point Schalfli symbol {4 4 .6 2 } and displays a sql/Shubnikov tetragonal plane net topology, whereas 4 forms a one-dimensional CP which subsequently extended to 3D supramolecular networks through hydrogen bonding interactions. Gas adsorption studies reveal that compounds 1 and 2 show selective adsorption of CO 2 over other gases (N 2 , CH 4 ) at low temperature, whereas 3 and 4 show no uptake. Vapor sorption studies reveal that compounds 1, 2, and 4 show high uptake capacities for H 2 O over MeOH and EtOH. Solid state luminescence studies of compounds 1, 3, and 4 display significant red shifts compared to free ligands.

Synthesis of Highly Stable Porous Metal‐Iminodiacetic Acid Gels from A Novel IDA Compound

“…Besides the considerations mentioned above about multi-carboxylate ligands, BP-IDA has its own remarkable features. Firstly, conformationally flexible ligands with auxiliary chemical interaction have often been employed to design coordination polymers [21][22][23] and metal-organic gels, and BP-IDA contains flexible multi-carboxylate structures coincidentally. As a polycarboxylic acid, BP-IDA is similar to EDTA.…”

Crystal structure, infrared spectra and luminescence of a 1D Cd coordination polymer with 4-nitrophthalic acid and 1,10-phenanthroline monohydrate ligands

“…[10][11][12][13][14][15]. Among these factors, the organic ligand plays an important role because changing it can control and adjust the coordination frameworks and topologies [16][17][18][19]. Since a carboxylate group can bridge metal ions and lock their position into M-O-C clusters, which can act as rigid entities and improve the stabilization of the compounds, di and polycarboxylic acids are widely used as bridging ligands to construct coordination frameworks with versatile structures [20][21][22][23][24][25].…”

Syntheses and Characterizations of Two New Cadmium Complexes Based on Oxalate

“…[1][2][3][4] Oxalic acid (H 2 ox) or oxalate has been focused upon as a ligand for a long time because of its ability to bind metal centers strongly with diverse coordination modes (Scheme 1), e.g., μ 2 -, μ 3 -, μ 4 -, μ 5 -, μ 6 -bridging or bidentate chelation for metal centers. [5][6][7] These bridging coordination modes can provide both rigidity and preferred coordination specificity for metal centers, 8 and thus easily form chains or planes, thereby allowing the formation of higher dimensional structures.…”

“…13 In addition, the crystal structures of the complexes can be controlled by subtle modification of the reaction conditions or starting materials. For example, the reaction of CdCl 2 Á2.5H 2 O, oxalic acid, imidazole, and H 2 O can give a 3-D complex [Cd 2 (ox)(OH) 2 ] n , in which imidazole is not found as the ligand or guest. 5 If Cd(Ac) 2 Á2H 2 O, oxalic acid, imidazole, butan-2-ol, and H 2 O were taken as the starting materials, the 3-D complex [Cd(C 2 O 4 ) 2 (C 3 N 2 H 4 ) 3 Single-Crystal Structure Determination.…”