The Next Chapter in MOF Pillaring Strategies: Trigonal Heterofunctional Ligands To Access Targeted High-Connected Three Dimensional Nets, Isoreticular Platforms

Abstract

A new pillaring strategy, based on a ligand-to-axial approach that combines the two previous common techniques, axial-to-axial and ligand-to-ligand, and permits design, access, and construction of higher dimensional MOFs, is introduced and validated. Trigonal heterofunctional ligands, in this case isophthalic acid cores functionalized at the 5-position with N-donor (e.g., pyridyl- or triazolyl-type) moieties, are designed and utilized to pillar pretargeted two-dimensional layers (supermolecular building layers, SBLs). These SBLs, based on edge transitive Kagomé and square lattices, are cross-linked into predicted three-dimensional MOFs with tunable large cavities, resulting in isoreticular platforms.

Tuning the topological states in metal-organic bilayers

“…By increasing the interlayer distance to d 1 = 3.9Å, the layer separation of the edge states is strengthened, where we find | 1L|e That is, in addition to the external electric field, the interlayer distance is another degree of freedom which allow us to control the localization of the topologically protected edge states in (MC 4 S 4 ) 3 BL nanoribbons. It is worth to mention that such a control on the interlayer distance, between the organic layers, can be done through the current pillaring processes in MOFs [33,34].…”

Bio-Inspired Metal-Organic Frameworks in the Pharmaceutical World: A Brief Review

“…This implies the chemical cross-linking of layers via accessible bridging sites on the layers, such as open metal sites or functionalized positions on the organic linker, whose judicious selection is mandatory. This approach, in principle, allows to predict MOFs with tuneable cavities, the endless expansion of confined space (as cavities and pores), and its modularity further permits an easy functionalization and introduction of additional functionalities [74] to aim specific applications. The prerequisites for this approach are (a) a blueprint net with minimal edge transitivity, rather singular, exclusive for the particular pillaring of the given building units and (b) the reaction conditions to allow the consistent formation of the SBL in situ.…”

Structural Diversity and Selective CO2 Adsorption of Metal– Organic Frameworks Built with a Flexible Dipyridyl Ligand and Different Carboxylates

“…Also, the flexible organic ligands, especially the one with aliphatic backbones, when used as building blocks for the construction of porous MOFs can produce various unexpected structures by imparting a high degree of conformational freedom due to the bending and rotation of the flexible backbone upon coordination to the metal center . Most of the reported flexible ligands are based on imidazole and pyridine systems, but systems with long aliphatic backbones having a chelating site for metal ions is absent from literature . In this context, we selected a highly flexible and rarely used organic linker, L , (Scheme ) where two pyridyl moieties are linked by a chain of six aliphatic atoms (four carbon and two nitrogens).…”