Discovery of Zr-based metal-organic polygon: Unveiling new design opportunities in reticular chemistry

Abstract

Metal-based secondary building unit and the shape of organic ligands are the two crucial factors for determining the final topology of metal-organic materials. A careful choice of organic and inorganic structural building units occasionally produces unexpected structures, facilitating deeper fundamental understanding of coordination-driven self-assembly behind metal-organic materials. Here, we have synthesized a triangular metal-organic polygon (MOT-1), assembled from bulky tetramethyl terephthalate and Zr-based secondary building unit. Surprisingly, the Zr-based secondary building unit serves as an unusual ditopic Zr-connector, to form metal-organic polygon MOT-1, proven to be a good candidate for water adsorption with recyclability. This study highlights the interplay of the geometrically frustrated ligand and secondary building unit in controlling the connectivity of metal-organic polygon. Such a strategy can be further used to unveil a new class of metal-organic materials.

Exploring the Solution Formation of UiO Family Hf Metal-Organic Framework clusters with in situ X-Ray Pair Distribution Function Analysis

“…This further suggests that, by adjusting the temperature of the reaction to take advantage of the different rates of cluster condensation and of framework growth, it may be possible to allow more time for the clusters to join together prior to coordination by inter-cluster linkers, and so obtain "multi-cluster" species intermediate between the double cluster and previously-observed infinite 1-D chains, all based on the M6 single cluster unit. 8 Alongside the previous studies, our work with formic acid corroborates that cluster formation in these UiO systems is determined by a complex interplay of temperature, ageing, concentration of metal salt and the type, concentration and pH of acid (which can act as a modulator and as directing groups 43,71,75 ). The complex processes discussed in this work motivate further exploration to enable understanding in greater detail, and hence improved exploitation.…”

“…33,34,[36][37][38] The degree of hydrolysis, and subsequent aggregation, can be modulated by the use of additional reagents, 37 such as acid, 39 which in some MOF syntheses is required to form the crystalline framework, 40,41 and in others is used to control particle morphology. 15,40,42,43 Monocarboxylic acids are often chosen for this purpose; since they can possess a wide range of metal-ligand binding strengths, a judicious choice of carboxylic acid can "block" coordination sites on the cluster to further nucleophilic attack preventing, in the case of water/hydroxides, cluster aggregation, or for linkers, the formation of multi-cluster framework species. 13,34,44 However, while it is now clear that water and modulating ligands are critical to the identity and stability of the resultant metal clusters (from ligand-terminated molecular clusters 30 through to MOFs 12,34,[45][46][47][48] ), the exact interplay of these factors, especially in multi-species reaction mixtures, is not well understood.The degree of cluster aggregation is also directly affected by the temperature and duration of the synthesis.…”

Supramolecular Coordination Cages Based on N‐Heterocyclic Carbene‐Gold(I) Ligands and Their Precursors: Self‐Assembly, Structural Transformation and Guest‐Binding Properties

“…[5] CpZr-based SCCs (Cp = η 5 -C 5 H 5 ) have received considerable interests owing to their structural tunability and amenability to post-synthetic modifications. [6] Diverse CpZr-based SCCs with different geometries, including tetrahedral, [7] cubic, [8] cigar-like or trigonal bipyramid, [9] triangle, [10] rectangle [11] and zigzagshaped [11] architectures built from trinuclear zirconocene oxide cluster have been reported. An important subject of this field is the ability to construct structures with functionalized pores.…”

Exploring the Solution Formation of UiO Family Hf Metal-Organic Framework clusters with in situ X-Ray Pair Distribution Function Analysis

“…33,34,[36][37][38] The degree of hydrolysis, and subsequent aggregation, can be modulated by the use of additional reagents, 37 such as acid, 39 which in some MOF syntheses is required to form the crystalline framework, 40,41 and in others is used to control particle morphology. 15,40,42,43 Monocarboxylic acids are often chosen for this purpose; since they can possess a wide range of metal-ligand binding strengths, a judicious choice of carboxylic acid can "block" coordination sites on the cluster to further nucleophilic attack preventing, in the case of water/hydroxides, cluster aggregation, or for linkers, the formation of multi-cluster framework species. 13,34,44 However, while it is now clear that water and modulating ligands are critical to the identity and stability of the resultant metal clusters (from ligand-terminated molecular clusters 30 through to MOFs 12,34,[45][46][47][48] ), the exact interplay of these factors, especially in multi-species reaction mixtures, is not well understood.The degree of cluster aggregation is also directly affected by the temperature and duration of the synthesis.…”