Highly stable Ni₈-pyrazolate metal–organic frameworks for adsorption of methylene blue from water

Abstract

Three Ni8-pyrazolate metal-organic frameworks, namely Ni8-NiL1, Ni8-CuL1 and Ni8-CuL2, were prepared by using metallosalen-based ligands (NiL1, CuL1, CuL2). The octanuclear cubic clusters [Ni8(OH)4(H2O)2] render these materials with sufficient robustness, enabling...

Metal–Organic Azolate Frameworks with an Acetylene-bis-pyrazolate Linker: Assessing the Role of the Triple-Bond Spacer in Gas and Vapor Sorption

“…[Ni 8 (OH) 4 (H 2 O) 2 (bpe) 6 ]·nSolv ( 2 ·nSolv) is a new member of the isoreticular [Ni 8 (OH) 4 (H 2 O) 2 L 6 ] series with the first representative reported by Masciocchi et al and continued by others. − ,− The new MOF 2 ·nSolv crystallizes as expected in the cubic space group . The asymmetric unit contains one Ni­(II) atom, a quarter of a bpe 2– molecule and a Ni-bridging μ 4 -OH – or μ 4 -H 2 O group treated as sharing O atoms of the respective ligands in a statistical occupation ratio of 2:1, leading to the formation of [Ni 8 (OH) 4 (H 2 O) 2 ] 12+ clusters as part of a highly symmetric {Ni 8 (OH) 4 (H 2 O) 2 (pz) 12 }-SBU (Figure a,b) of cubic symmetry.…”

“…In the cubic SBU {Ni 8 (OH) 4 (H 2 O) 2 (pz) 12 }, the Ni 2+ cations are located at the corners of a cube, Ni-bridging μ 4 -OH – or μ 4 -H 2 O groups above the center of the faces and 12 Ni-bridging pyrazolate groups on the edges (Figure c). Besides a high stability due to strong Ni–N coordination bonds, the cubic nature of this SBU makes it an ideal candidate for highly porous fcu structures offering many potential applications in several fields. − An isoreticular series of MOFs with formula [Ni 8 (μ 4 -X) 6 (μ 4 -L) 6 ] and such a cubic SBU connected by linear linkers was first presented by Masciocchi et al, expanded by Padial et al and studied further by Freund et al, Zhang et al and others. − In this series the cubic SBUs form (12)-connected 3D-networks with fcu topology, resulting in octahedral and tetrahedral pores.…”

Synthesis and Properties of Cobalt/Nickel-Iron-Antimony(III, V)-Oxo Tartrate Cluster-Based Compounds

“…Thus, it is crucial to solve the environmental pollution problems caused by these species [25][26][27]. In recent years, a number of scholars have utilized metal oxides with precise atomic structures as catalysts for photodegradation of organic dye wastewater [8,28,29]. On account of this, we investigated the photocatalytic degradation performance of compounds 2 and 4 as inhomogeneous reaction photocatalysts using methylene blue (MB) as a simulated pollutant.…”