Metal-Organic Polyhedra as Building Blocks for Porous Extended Networks

Altres ajuts: "la Caixa" Foundation (ID 100010434)Metal-organic polyhedra (MOPs) are a subclass of coordination cages that can adsorb and host species in solution and are permanently porous in solid-state. These characteristics, together with the recent development of their orthogonal surface chemistry and the assembly of more stable cages, have awakened the latent potential of MOPs to be used as building blocks for the synthesis of extended porous networks. This review article focuses on exploring the key developments that make the extension of MOPs possible, highlighting the most remarkable examples of MOP-based soft materials and crystalline extended frameworks. Finally, the article ventures to offer future perspectives on the exploitation of MOPs in fields that still remain ripe toward the use of such unorthodox molecular porous platforms

(Bio)Functionalisation of Metal-Organic Polyhedra by Using Click Chemistry

The surface chemistry of Metal-Organic Polyhedra (MOPs) is crucial to their physicochemical properties because it governs how they interact with external substances such as solvents, synthetic organic molecules, metal ions, and even biomolecules. Consequently, the advancement of synthetic methods that facilitate the incorporation of diverse functional groups onto MOP surfaces will significantly broaden the range of properties and potential applications for MOPs. This study describes the use of copper(I)-catalysed, azide-alkyne cycloaddition (CuAAC) click reactions to post-synthetically modify the surface of alkyne-functionalised cuboctahedral MOPs. To this end, a novel Rh(II)-based MOP with 24 available surface alkyne groups was synthesised. Each of the 24 alkyne groups on the surface of the "clickable" Rh-MOP can react with azide-containing molecules at room temperature, without compromising the integrity of the MOP. The wide substrate catalogue and orthogonal nature of CuAAC click chemistry was exploited to densely functionalise MOPs with diverse functional groups, including polymers, carboxylic and phosphonic acids, and even biotin moieties, which retained their recognition capabilities once anchored onto the surface of the MOP

Multicomponent, Functionalized HKUST-1 Analogues Assembled via Reticulation of Prefabricated Metal-Organic Polyhedral Cavities

Metal-organic frameworks (MOFs) assembled from multiple building blocks exhibit greater chemical complexity and superior functionality in practical applications. Herein, we report a new approach based on using prefabricated cavities to design isoreticular multicomponent MOFs from a known parent MOF. We demonstrate this concept with the formation of multicomponent HKUST-1 analogues, using a prefabricated cavity that comprises a cuboctahedral Rh(II) metal-organic polyhedron functionalized with 24 carboxylic acid groups. The cavities are reticulated in three dimensions via Cu(II)-paddlewheel clusters and (functionalized) 1,3,5-benzenetricarboxylate linkers to form three- and four-component HKUST-1 analogues

Multicomponent, Functionalized HKUST‑1 Analogues Assembled via Reticulation of Prefabricated Metal–Organic Polyhedral Cavities [Dataset]

89 pages. -- PDF file includes: S1. Materials and methods; S1.1. Materials and characterization; S1.2. Experimental methods; S1.2.1. Synthesis of COOH-RhMOP, (Br)btc, (NO2)btc and (COOH)btc; S1.2.2. Stability of COOH-RhMOP under solvothermal conditions; S1.2.3. Synthesis of RhCu-btc-HKUST-1, RhCu-(Br)btc-HKUST-1, RhCu-(NO2)btc-HKUST-1, RhCu-(NH2)btc-HKUST-1 and RhCu-(COOH)btc-HKUST-1; S.1.2.4. Blank reactions for RhCu-btc-HKUST-1; S.1.2.5. Acidic disassembly of RhCu-btc-HKUST-1; S.1.2.6. Acidic digestion of RhCu-(Br)btc-HKUST-1, RhCu-(NO2)btc-HKUST-1, RhCu-(NH2)btc-HKUST-1 and RhCu-(COOH)btc-HKUST-1; S1.2.7. Study of the hydrolytic stability of RhCu-btc-HKUST-1 and Cu(II)-HKUST- 1; S1.2.8 Study of the methylene blue removal with RhCu-btc-HKUST-1 and Cu(II)-HKUST-1; S1.2.9. Study of the catalytic activity of RhCu-btc-HKUST-1 and RhCu-(COOH)btc-HKUST-1; S1.3. Computational methods; S2. Characterization of RhCu-btc-HKUST-1; S3. Characterization of Cu(II)-HKUST-1; S4. Hydrolytic stability study of RhCu-btc-HKUST-1 and Cu(II)-HKUST-1; S4.1. DFT calculations of Rh(II) and Cu(II) paddlewheels in water; S5. Characterization of RhCu-(Br)btc-HKUST-1; S6. Characterization of RhCu-(NO2)btc-HKUST-1; S7. Characterization of RhCu-(NH2)btc-HKUST-1; S8. Characterization of RhCu-(COOH)btc-HKUST-1.Metal–organic frameworks (MOFs) assembled from multiple building blocks exhibit greater chemical complexity and superior functionality in practical applications. Herein, we report a new approach based on using prefabricated cavities to design isoreticular multicomponent MOFs from a known parent MOF. We demonstrate this concept with the formation of multicomponent HKUST-1 analogues, using a prefabricated cavity that comprises a cuboctahedral Rh­(II) metal–organic polyhedron functionalized with 24 carboxylic acid groups. The cavities are reticulated in three dimensions via Cu­(II)-paddlewheel clusters and (functionalized) 1,3,5-benzenetricarboxylate linkers to form three- and four-component HKUST-1 analogues.Peer reviewe

A Toolbox for the Synthesis of Multifunctionalized Mesoporous Silica Nanoparticles for Biomedical Applications

Mesoporous silica nanoparticles (MSNs) are considered as promising next-generation nanocarriers for health-related applications. However, their effectiveness mostly relies on their efficient and surface-specific functionalization. In this contribution, we explored different strategies for the rational multistep synthesis of functional MCM-48-type MSNs with selectively created active inner and/or external surfaces. Functional groups were first installed using a combination of (delayed) co-condensation and post-grafting procedures. Both amine [(3-aminopropyl)­triethoxysilane (APTS)] and thiol [(3-mercaptopropyl)­trimethoxysilane (MPTS)] silanes were used, in various addition sequences. Following this, the different platforms were further functionalized with polyethylene glycol and/or with a pro-chelate ligand used as a magnetic resonance imaging contrast agent (diethylenetriaminepentaacetic acid chelates) and/or loaded with quercetin and/or grafted with an organic dye (rhodamine). The efficiency of the multiple grafting strategies and the effects on the MSN carrier properties are presented. Finally, the colloidal stability of the different systems was evaluated in physiological media, and preliminary tests were performed to verify their drug release capability. The use of MPTS appeared beneficial when compared to APTS in delayed co-condensation procedures to preserve both selective distribution of the functional groups, reactive functionality, and pore ordering. Our results provide in-depth insights into the efficient design of (multi)­functional MSNs and especially on the crucial role played by the sequence of step-by-step functionalization methods aiming to produce multipurpose and stable bioplatforms

In Situ X-Ray Synchrotron Profile Analysis During High Pressure Torsion of Ti

X-Ray Line Profile Analysis is a powerful method to characterize the microstructure of deformed materials, especially when high energy and brilliant Synchrotron radiation enables investigations with high time and spatial resolution. Parameters like dislocation density, dislocation arrangement as well as scattering domain size and it's distribution are parameters of a physical model of peak broadening, which can be applied to high quality diffraction measurements. A small high-pressure-torsion-machine was designed in order to perform in-situ diffraction experiments during the deformation process at hydrostatic pressures up to 8GPa in order to follow the strain as well as pressure induced microstructural characteristics of deformed samples. This was possible with the ideal design and equipment at the High-Energy-Materials-Science-beamline at PETRA III in Hamburg. First results of experiments on HPT-deformed Ti show that at 6 GPa the high pressure $\omega$-phase is initiated only with additional shear deformation

Porous and Meltable Metal-Organic Polyhedra for the Generation and Shaping of Porous Mixed-Matrix Composites

Here, we report the synthesis of BCN-93, a meltable, functionalized and permanently porous metal-organic polyhedron (MOP), and its subsequent transformation into amorphous or crystalline, shaped, self-standing, transparent porous films via melting and subsequent cooling. The synthesis entails the outer functionalization of a MOP with meltable polymer chains: in our model case, we functionalized a Rh(II)-based cuboctahedral MOP with polyethylene glycol (PEG). Finally, we demonstrate that once melted, BCN-93 can serve as a porous matrix into which other materials or molecules can be dispersed to form mixed-matrix composites. To illustrate this, we combined BCN-93 with one of various additives (either two MOF crystals, a porous cage, or a linear polymer) to generate a series of mixed-matrix films, each of which exhibited greater CO2 uptake relative to the parent film

A Toolbox for the Synthesis of Multifunctionalized Mesoporous Silica Nanoparticles for Biomedical Applications

Mesoporous silica nanoparticles (MSNs) are considered as promising next-generation nanocarriers for health-related applications. However, their effectiveness mostly relies on their efficient and surface-specific functionalization. In this contribution, we explored different strategies for the rational multistep synthesis of functional MCM-48-type MSNs with selectively created active inner and/or external surfaces. Functional groups were first installed using a combination of (delayed) co-condensation and post-grafting procedures. Both amine [(3-aminopropyl)triethoxysilane (APTS)] and thiol [(3-mercaptopropyl)trimethoxysilane (MPTS)] silanes were used, in various addition sequences. Following this, the different platforms were further functionalized with polyethylene glycol and/or with a pro-chelate ligand used as a magnetic resonance imaging contrast agent (diethylenetriaminepentaacetic acid chelates) and/or loaded with quercetin and/or grafted with an organic dye (rhodamine). The efficiency of the multiple grafting strategies and the effects on the MSN carrier properties are presented. Finally, the colloidal stability of the different systems was evaluated in physiological media, and preliminary tests were performed to verify their drug release capability. The use of MPTS appeared beneficial when compared to APTS in delayed co-condensation procedures to preserve both selective distribution of the functional groups, reactive functionality, and pore ordering. Our results provide in-depth insights into the efficient design of (multi)functional MSNs and especially on the crucial role played by the sequence of step-by-step functionalization methods aiming to produce multipurpose and stable bioplatforms.© 2018 American Chemical Societ