A Wavy Two-Dimensional Covalent Organic Framework from Core- Twisted Polycyclic Aromatic Hydrocarbons

A high degree of crystallinity is an essential aspect in two-dimensional covalent organic frameworks, as many properties depend strongly on the structural arrangement of the different layers and their constituents. We introduce herein a new design strategy based on core-twisted polycyclic aromatic hydrocarbon as rigid nodes that give rise to a two-dimensional covalent organic framework with a wavy honeycomb (chairlike) lattice. The concave–convex self-complementarity of the wavy two-dimensional lattice guides the stacking of framework layers into a highly stable and ordered covalent organic framework that allows a full 3D analysis by transmission electron microscopy revealing its chairlike …

Effect of linker distribution in the photocatalytic activity of multivariate mesoporous crystals

The use of Metal-Organic Frameworks as crystalline matrices for the synthesis of multiple component or multivariate solids by the combination of different linkers into a single material has emerged as a versatile route to tailor the properties of single-component phases or even access new functions. This approach is particularly relevant for Zr6-MOFs due to the synthetic flexibility of this inorganic node. However, the majority of materials are isolated as polycrystalline solids, which are not ideal to decipher the spatial arrangement of parent and exchanged linkers for the formation of homogeneous structures or heterogeneous domains across the solid. Here we use high-throughput methodologi…

Heterometallic Titanium–Organic Frameworks by Metal-Induced Dynamic Topological Transformations

Reticular chemistry has boosted the design of thousands of metal and covalent organic frameworks for unlimited chemical compositions, structures, and sizable porosities. The ability to generate porous materials at will on the basis of geometrical design concepts is responsible for the rapid growth of the field and the increasing number of applications derived. Despite their promising features, the synthesis of targeted homo- and heterometallic titanium–organic frameworks amenable to these principles is relentlessly limited by the high reactivity of this metal in solution that impedes the controlled assembly of titanium molecular clusters. We describe an unprecedented methodology for the syn…

Tetrazine Linkers as Plug-and-Play Tags for General Framework Functionalization and C60 Conjugation

The value of covalent post-synthetic modification in expanding the chemistry and pore versatility of reticular solids is well documented. Here we use mesoporous crystals of UiO-68-TZDC to demonstrate the value of tetrazine connectors for all-purpose inverse electron-demand Diels-Alder ligation chemistry. Our results suggest a positive effect of tetrazine reticulation over its reactivity for quantitative one-step functionalization with a broad scope of alkene or alkyne dienophiles into pyridazine and dihydropyridazine frameworks. This permits generating multiple pore environments with diverse chemical functionalities and the expected accessible porosities, that is also extended to the synthe…

Wrapping up Metal-Organic Framework Crystals with Carbon Nanotubes

The presence of tetrazine units in the organic nodes of UiO- 68-TZCD controls the formation of ultrathin coatings of single wall nanotubes that decorate the surface of the crystal. These crystal hybrids can be prepared straightforwardly in one step and are extraordinarily respectful with the properties of the framework for combination of mesoporosity and surface areas near 4.000 m·g-1 ,with excellent stability in water, and conductivities at room temperature of 4·10-2 S·cm-1 even at very low carbon weight contents (2.3 wt%).

π-Interpenetrated 3D Covalent Organic Frameworks from Distorted Polycyclic Aromatic Hydrocarbons.

Three-dimensional covalent organic frameworks (3D COFs) with a pcu topology have been obtained from distorted polycyclic aromatic hydrocarbons acting as triangular antiprismatic (D3d ) nodes. Such 3D COFs are six-fold interpenetrated as the result of interframework π-stacking, which enable charge transport properties that are not expected for 3D COFs.

Tetrazine Linkers as Plug‐and‐Play Tags for General Metal‐Organic Framework Functionalization and C 60 Conjugation

Three dimensional nanoscale analysis reveals aperiodic mesopores in a covalent organic framework and conjugated microporous polymer.

The integrated analytical approach developed in this study offers a powerful methodology for the structural characterisation of complex molecular nanomaterials. Structures of a covalent organic framework based on boronate esters (COF-5) and a conjugated microporous polymer (Aza-CMP) have been investigated by a combination of several electron microscopy techniques elucidating the three-dimensional topology of the complex polycrystalline (COF) and non-crystalline (CMP) materials. Unexpected, aperiodic mesoporous channels of 20-50 nm in diameter were found to be penetrating the COF and CMP particles, which cannot be detected by X-ray diffraction techniques. The mesopores appear to be stable un…

Permanent Porosity in Hydroxamate Titanium-Organic Polyhedra.

Following the synthesis of hydroxamate titanium–organic frameworks, we now extend these siderophore-type linkers to the assembly of the first titanium–organic polyhedra displaying permanent porosity. Mixed-linker versions of this molecular cage (cMUV-11) are also used to demonstrate the effect of pore chemistry in accessing high surface areas of near 1200 m2·g–1.

Translocation of enzymes into a mesoporous MOF for enhanced catalytic activity under extreme conditions

Translocation of protease into mesoporous MIL-101-NH2 results in enhanced catalytic activity, excellent recyclability and tolerance to competing enzymes.

An Expanded 2D Fused Aromatic Network with 90-Ring Hexagons

[EN]Two-dimensional fused aromatic networks (2D FANs) have emerged as a highly versatile alternative to holey graphene. The synthesis of 2D FANs with increasingly larger lattice dimensions will enable new application perspectives. However, the synthesis of larger analogues is mostly limited by lack of appropriate monomers and methods. Herein, we describe the synthesis, characterisation and properties of an expanded 2D FAN with 90-ring hexagons, which exceed the largest 2D FAN lattices reported to date. This work was carried out with support from the Basque Science Foundation for Science (Ikerbasque),POLYMAT, the University of the Basque Country,Gobierno Vasco (BERC programme) and Gobierno d…

CCDC 2023345: Experimental Crystal Structure Determination

Related Article: Belén Lerma-Berlanga, Carolina R. Ganivet, Neyvis Almora-Barrios, Sergio Tatay, Yong Peng, Josep Albero, Oscar Fabelo, Javier González-Platas, Hermenegildo García, Natalia M. Padial, Carlos Martí-Gastaldo|2021|J.Am.Chem.Soc.|143|1798|doi:10.1021/jacs.0c09015

CCDC 1885013: Experimental Crystal Structure Determination

Related Article: Marta Martínez-Abadía, Craig T. Stoppiello, Karol Strutynski, Belén Lerma-Berlanga, Carlos Martí-Gastaldo, Akinori Saeki, Manuel Melle-Franco, Andrei N. Khlobystov, Aurelio Mateo-Alonso|2019|J.Am.Chem.Soc.|141|14403|doi:10.1021/jacs.9b07383