Constructing calixarene-supported high nuclearity Co₂₇, Co₂₈ and Ni₁₈Na₆ clusters with triazoles as co-bridges

Abstract

Four high nuclearity compounds are constructed by M4-calixarene SBUs and triazole co-bridges.

Topological insights in polynuclear Ni/Na coordination clusters derived from a schiff base ligand

“…However, since 2007, Ni II /Na I CCs with nuclearity over 10 have been reported far more frequently. The highest reported of these is a Ni 18 Na 6 cluster [63] and the second Ni 16 Na 4 [64], both synthesised by calix [4] arene-type ligands and the third is a Ni 16 Na 2 cluster. In addition, two Ni 12 Na 2 clusters were reported by Christou et al [37,65].…”

Thiacalixarene-Supported Irregular Co26 and Ni28 High-Nuclearity Clusters with Pyridyl-Diphosphonates: Strategies to Create Active Metal Sites and Fabricate Multicomponent Materials

“…High nuclearity polyhedral coordination clusters (PCCs) are a discrete chemically and topologically diverse family of molecule-based functional materials that endue them various potential applications. − Although the nuclearity and structure of the cluster is a challenge to predict, many examples have been obtained by the modulation of metal ion sources and ligands assembly, among which polynuclear second building units (SBUs) self-assemble or are preorganized by metal ions and the multidentate organic ligands approach showed particular advances. − The multidentate ligands p - tert -butylthiacalix­[4]­arene (H 4 TC4A, Scheme a) and its derivatives are favorable to form a cationic tetranuclear M II 4 –thiacalixarene (M = Fe, Co, Ni, Cu, etc., x = 1–4) core SBU, which can be further bridged by anionic auxiliary ligands to fabricate high nuclearity clusters. − For instance, we and others have reported Co or Ni clusters with nuclearity from 24 to 48 based on polynuclear M 4 –TC4A SUBs and auxiliary species with various shapes and bridging angles. − However, due to the structure of the conical-shaped M II 4 –TC4A core ( C 4 v ), symmetrical auxiliary ligands, e.g., aromatic diacid derivatives, are commonly lead to PCCs featured with symmetric platonic solid type polyhedron packing of M II 4 –TC4A cores, respectively. ,, In such PCCs, the metal centers are typically coordinated by auxiliary ligands in saturated modes, which make them hardly active either for derivation or for catalysts. Significant applications of these PCCs are highly dependent on the incorporated components, e.g., precious metal, by postmodification. ,− Recently, we have demonstrated that metal centers with more labile bonds enable significant photocatalytic properties for water splitting .…”

“…First, the M II 4 –calixarene unit bonds to less auxiliary ligands with more weakly coordinated solvent molecules either by ligand symmetry or coordination hindrance modulation . Another appealing route is to incorporate more metal centers different from those in the M II 4 –calixarene unit . To achieve such a goal, auxiliary ligands with different coordination sites and asymmetry nature may facilitate assembly of PCCs with labile bonds.…”

“…15 Another appealing route is to incorporate more metal centers different from those in the M II 4 −calixarene unit. 18 To achieve such a goal, auxiliary ligands with different coordination sites and asymmetry nature may facilitate assembly of PCCs with labile bonds. The 1-hydroxy-2-(3-pyridinyl)ethylidene-1,1-diphosphonic acid (risedronic acid, H 5 L, Scheme 1b) has been proven to be an efficient multidentate ligand with diversified coordination modes and excellent coordination ability to metal ions due to its eight potential coordination sites.…”

Solvent/Anion-Induced Structural Modification in a Discrete {Co14} Clusters

“…Metal–organic clustersdiscrete molecular architectures constructed through the coordination of metal ions and organic linkershave recently attracted considerable attention due to their intriguing structures, relevance to biological self-assembly, and potential for a variety of applications in magnetism, , catalysis, − nonlinear optical materials, , gas adsorption and storage, , and so on. Also, the design and synthesis of high-nuclearity metal clusters have become one of the most active fields in coordination chemistry and materials chemistry over the past few decades. − The synthetic routes to prepare these complexes have typically been based on the direct assembly of metal ions and organic ligands to date. Although these routes are always convenient, it remains difficult to find suitable reaction conditions to control the outcome of the assembly process.…”