Highly Thermally and Chemically Stable Nickel(II) Coordination Polymers: Tentative Studies on Their Sorption, Catalysis, and Magnetism

Abstract

The five new Ni(II) coordination polymers (CPs) {[Ni(bitp)(bpe) 0.5 (H 2 O) 2 ]•0.5bpe} n (1), {[Ni(bitp)(bpa) 0.5 (Hwhere H 2 bitp = 2-(benzimidazol-1-yl)terephthalic acid, bpe = 1,2-bis(4pyridyl)ethylene, bpa = 1,2-bis(4-pyridyl)ethylane, 4,4′-bpy = 4,4′bipyridine, 2,2′-bpy = 2,2′-bipyridine, and bipyam = 2,2′-bipyridylamine, were prepared under the same hydrothermal environments except for various N-donor ligands which can effectively regulate the structures of the complexes. For the bridging N-donor ligands bpe, bpa, and 4,4′-bpy, isostructural 1 and 2 feature three-dimensional (3D) layered-pillared frameworks with one-dimensional (1D) channels that house free bpe or bpa, while 3 is a wavelike two-dimensional (2D) stacked layer with similar 4,4′-bpy bridging auxiliary ligands. However, when terminal ligands 2,2′-bpy and bipyam are used, 2D 4 and 1D ladder chains 5 are obtained, respectively. Interestingly, 1−5 exhibit outstanding thermostability (up to 320 °C) and chemical stabilities (against boiling water, acids, bases, and organic solvents). Furthermore, on the basis of their highly thermal and chemical stability, tentative studies on the structures and properties (such as adsorption, catalysis, and magnetic properties) were undertaken. The gas sorption measurements show that 1 and 2 exhibit high adsorption selectivity of CO 2 over CH 4 . The catalytic reactions demonstrate the role of catalysts 1−5 to synthesize 3,6-bis(pyridin-4-yl)-1,2,4,5-tetrazine. The magnetic analyses indicate that there exist a zero field splitting (ZFS) on the Ni(II) ions in 1−5.

Two-Dimensional Metal-Organic Framework Materials: Synthesis, Structures, Properties and Applications

“…1513 1514 Another reaction involving of synthesis of 3,6-bis(pyridin-4-yl)-1,2,4,5-tetrazine from 4-cyanopyridine and hydrazine hydrate using a Ni-based 2D MOF is also studied. 1515 While ring opening of styrene oxides with amines and methanol using [Cd(tpim)(1,5-nds)] (1,5-nds = 1,5naphthalenedisulfonate; tpim = 2,4,5-tri(4-pyridyl)-imidazole) a n d [ G d 2 ( H 3 n m p ) 2 ] • x H 2 O (H 6 n m p = n i t r i l o -(trimethylphosphonic)acid), respectively, are also studied. 1516,1517 Condensation reactions including Knoevenagel and aldol condensation have been catalysed by 2D MOFs as well.…”

“…For example, formation of 2-(pyridin-4-yl)-1,4,5,6-tetrahydropyrimidine by the reaction of 4-cyanopyridine with 1,3-diaminopropane is catalyzed by isostructural 2D MOFs, [M 2 (L)­(py) 6 ]·H 2 O (M = Cd, Co, Ni, Cu; H 4 L = 5,5′-(1 H -2,3,5-triazole-1,4-diyl)­diisophthalic acid) in accordance to the Lewis acidity strength of metal centers . Another reaction involving of synthesis of 3,6-bis­(pyridin-4-yl)-1,2,4,5-tetrazine from 4-cyanopyridine and hydrazine hydrate using a Ni-based 2D MOF is also studied . While ring opening of styrene oxides with amines and methanol using [Cd­(tpim)­(1,5-nds)] (1,5-nds = 1,5-naphthalenedisulfonate; tpim = 2,4,5-tri­(4-pyridyl)-imidazole) and [Gd 2 (H 3 nmp) 2 ]· x H 2 O (H 6 nmp = nitrilo­(trimethylphosphonic)­acid), respectively, are also studied. , …”

The first coordination compound of 6-fluoronicotinate: the crystal structure of a one-dimensional nickel(II) coordination polymer containing the mixed ligands 6-fluoronicotinate and 4,4′-bipyridine

“…Our goal was to prepare nickel(II) coordination polymers as the nickel(II) ion is relatively abundant, with a large ionic radius and defined stereochemistry, showing a high ligandfield stabilization energy, which enables the formation of nickel(II) coordination polymers with diverse topologies and high stabilities (Liu et al, 2019). We opted for nickel(II) coordination polymers with mixed ligands: 6-fluoronicotinate (6-Fnic) as the main ligand and 4,4 0 -bipyridine (4,4 0 -bpy), a well-established, bridging N-donor ligand, frequently used in the design of nickel(II) coordination polymers, as the supporting ligand.…”

Spontaneous Resolution and Structure Transformation of NiII Metal–Organic Frameworks from an Achiral Precursor

“…To overcome this limitation, heterogeneous catalysts have been developed. Some reports have employed MOFs as promising heterogeneous catalysts. − Thus, the development of suitable MOF-based catalysts for this reaction is a topic of great interest.…”