Periodic Reporting for period 2 - CLIPOFF-CHEM (Clip-off Chemistry: Design and Synthesis of New Materials via Programmable Disassembly of Reticular Materials)
Période du rapport: 2023-04-01 au 2024-09-30
The CLIPOFF-CHEM project aims to develop a new synthetic approach called Clip-off Chemistry, which relies on orthogonal bond cleavage within molecular materials. Among the various types of molecular materials, reticular materials are particularly promising as precursor materials for Clip-off Chemistry. Reticular materials can be seen as the linkage of repetitive units or fragments formed by connecting basic inorganic and/or organic building blocks. These units or fragments, which can include clusters, cages, macrocycles, chains, layers, among others, may exhibit new properties and functions on their own, thereby serving as a new source of molecules or materials when isolated from the reticular material. Clip-off Chemistry aims to isolate these units or fragments via orthogonal bond cleavage (e.g. olefinic bonds using ozonolysis) of the connections that link them in the reticular materials. Within the CLIPOFF-CHEM project, we are defining, developing, and applying this synthetic approach to program the cleavage of metal-organic frameworks (MOFs) to synthesize functional metal-organic clusters, cages, two-dimensional layers, one-dimensional wires, and other 3D MOFs. Similarly, the project aims to extend Clip-off Chemistry for use in Organic Chemistry for the synthesis of organic molecules, macromolecules, and materials such as macrocycles and polymers. In summary, CLIPOFF-CHEM will provide the scientific community with a new tool to access new molecules and materials with fascinating properties that will surely find myriad applications for social, economic, or industrial benefit.
During the first half of the CLIPOFF-CHEM project, we have focused on the synthesis and characterization of various organic linkers and reticular materials. This effort has resulted in the successful synthesis of the majority of the metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and metal-organic polyhedra (MOPs) planned to be used as precursors in this phase of the project. Some of the synthesized 3D MOFs have been utilized to demonstrate their topological modification into other 3D MOFs. Furthermore, we have started the use of Clip-Off chemistry to synthesize 3D MOFs with modified porosity profiles. Additionally, novel approaches have been explored to induce flexibility and self-healing behavior in 3D structures, as well as the selective and reversible disassembly of merged edge-transitive nets through the targeted bond cleavage in 3D MOFs.
Within this project, we have also begun the synthesis of 2D layers and 1D wires from 3D MOFs through Clip-off Chemistry. To accomplish this, we selected a Zr-based MOF that was used to obtained 2D nanosheets through solid-state ozonolysis followed by methanol treatment. Additionally, selective bond cleavage in a 3D Al-MOF has enabled the production of 1D metal-organic wires. Furthermore, we have successfully expanded the application of Clip-off Chemistry to a 0-D system by converting a metal-organic polyhedron (MOP) into a metal-organic macrocycle and other supramolecular complexes. Building upon these findings, we have initiated the use of Clip-off Chemistry to synthesize metal-organic clusters and cages/polyhedra (MOPs) through the selective cleavage of a 3D MOF. Employing this method, we have achieved the synthesis of a Sc3O cluster functionalized with aldehyde groups and the well-known cuboctahedral Cu(II)-MOP functionalized with aldehyde or carboxylic acid groups.
Lastly, we have expanded the application of Clip-off Chemistry to purely organic covalent organic frameworks (COFs), yielding highly promising results for the synthesis of organic amide-linked hexagonal macrocycles. In this context, macrocycle products with high yields and purity have been obtained via Clip-off chemistry, enabling the isolation of four isoreticular amide-COF macrocycles with internal diameters of 35 Å, 42 Å and 50 Å, as well as a highly hydrophobic species resulting from the incorporation of fluorine atoms within the pores.
Within this project, we have also begun the synthesis of 2D layers and 1D wires from 3D MOFs through Clip-off Chemistry. To accomplish this, we selected a Zr-based MOF that was used to obtained 2D nanosheets through solid-state ozonolysis followed by methanol treatment. Additionally, selective bond cleavage in a 3D Al-MOF has enabled the production of 1D metal-organic wires. Furthermore, we have successfully expanded the application of Clip-off Chemistry to a 0-D system by converting a metal-organic polyhedron (MOP) into a metal-organic macrocycle and other supramolecular complexes. Building upon these findings, we have initiated the use of Clip-off Chemistry to synthesize metal-organic clusters and cages/polyhedra (MOPs) through the selective cleavage of a 3D MOF. Employing this method, we have achieved the synthesis of a Sc3O cluster functionalized with aldehyde groups and the well-known cuboctahedral Cu(II)-MOP functionalized with aldehyde or carboxylic acid groups.
Lastly, we have expanded the application of Clip-off Chemistry to purely organic covalent organic frameworks (COFs), yielding highly promising results for the synthesis of organic amide-linked hexagonal macrocycles. In this context, macrocycle products with high yields and purity have been obtained via Clip-off chemistry, enabling the isolation of four isoreticular amide-COF macrocycles with internal diameters of 35 Å, 42 Å and 50 Å, as well as a highly hydrophobic species resulting from the incorporation of fluorine atoms within the pores.
Progress on the CLIPOFF-CHEM project has confirmed that Clip-off Chemistry can effectively serve as a novel approach for synthesizing molecules and materials by selectively breaking bonds in molecular precursor materials. Several significant advancements beyond the current state of the art have been achieved. These include demonstrating that bond cleavage in reticular materials can be both quantitative and selective; effective in both solid-phase and solution-phase chemistry; capable of occurring in a single-crystal-to-single-crystal manner throughout the entire bulk precursor sample; and controllable to form aldehyde or carboxylic acid groups. These demonstrations unequivocally establish that Clip-off Chemistry is ripe for further exploration until the conclusion of the project, to broaden the scope of bond cleavage reactions and expand the repertoire of metal-organic and organic molecules and materials that can be synthesized using this innovative approach. For instance, we anticipate utilizing Clip-off Chemistry to enhance the diversity of new 2-D and 1-D nanomaterials; metal-organic cages and clusters; as well as novel purely organic compounds and structures, including catenanes, cages, macrocycles, and polymers. In summary, we firmly believe that Clip-off Chemistry will unlock access to a plethora of new molecular architectures and compounds.