A5075000824- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Crystallography and molecular interactions
- Metal-Organic Frameworks: Synthesis and Applications
- Supramolecular Chemistry and Complexes
- Covalent Organic Framework Applications
- Supramolecular Self-Assembly in Materials
- Luminescence and Fluorescent Materials
- Machine Learning in Materials Science
- Chemical Synthesis and Analysis
- Magnetism in coordination complexes
- Advanced Photocatalysis Techniques
- Molecular Sensors and Ion Detection
- Porphyrin and Phthalocyanine Chemistry
- Metal complexes synthesis and properties
- Mesoporous Materials and Catalysis
- Molecular Junctions and Nanostructures
- Advanced Battery Materials and Technologies
- Catalytic Cross-Coupling Reactions
- Chemical Synthesis and Characterization
- Cyclopropane Reaction Mechanisms
- Fuel Cells and Related Materials
- Synthetic Organic Chemistry Methods
- Surface Chemistry and Catalysis
- Metal-Catalyzed Oxygenation Mechanisms
University of Liverpool
2016-2025
Heriot-Watt University
2024
Imperial College London
2019-2023
Robert Bosch (Germany)
2023
Liverpool Hospital
2015-2021
University of Leeds
2010-2019
University of Southampton
2019
Central Michigan University
1973-1974
Abstract Covalent organic frameworks (COFs) are distinguished from other polymers by their crystallinity 1–3 , but it remains challenging to obtain robust, highly crystalline COFs because the framework-forming reactions poorly reversible 4,5 . More chemistry can improve 6–9 this typically yields with poor physicochemical stability and limited application scope 5 Here we report a general scalable protocol prepare imine COFs, based on an unexpected framework reconstruction. In contrast...
Quantum sieves for hydrogen isotopes One method improving the efficiency of separation from deuterium (D) is to exploit kinetic quantum sieving with nanoporous solids. This requires ultrafine pore apertures (around 3 angstroms), which usually leads low volumes and D 2 adsorption capacities. Liu et al. used organic synthesis tune size internal cavities cage molecules. A hybrid cocrystal contained both a small-pore that imparted high selectivity larger-pore enabled uptake. Science , this issue p. 613
Abstract Porous organic molecular materials are a subclass of porous solids that defined by their modular, structures, and the absence extended covalent or coordination bonding in solid‐state. As result, soluble they can be processed into different forms, such as mixed matrix membranes. The structure modules fine‐tuned for specific applications, gas isotope separations, some cases solid‐state properties these molecule viewed isolation. In this review, authors focus on design how tuned...
Three-dimensional (3D) covalent organic frameworks (COFs) are rare because there is a limited choice of building blocks that offer multiple reactive sites in polyhedral geometry. Here, we synthesized an cage molecule (Cage-6-NH2) was used as triangular prism node to yield the first cage-based 3D COF, 3D-CageCOF-1. This COF adopts unreported 2-fold interpenetrated acs topology and exhibits reversible dynamic behavior, switching between small-pore (sp) structure large-pore (lp) structure. It...
A series of porous organic cages is examined for the selective adsorption sulfur hexafluoride (SF6) over nitrogen. Despite lacking any metal sites, a cage, CC3, shows highest SF6/N2 selectivity reported material at ambient temperature and pressure, which translates to real separations in gas breakthrough column. The SF6 uptake these materials considerably higher than would be expected from static pore structures. location within elucidated by X-ray crystallography, it shown that cooperative...
The energy-efficient separation of alkylaromatic compounds is a major industrial sustainability challenge. use selectively porous extended frameworks, such as zeolites or metal-organic one solution to this problem. Here, we studied flexible molecular material, perethylated pillar[ n]arene crystals ( n = 5, 6), which can be used separate C8 compounds. Pillar[6]arene shown para-xylene from its structural isomers, meta-xylene and ortho-xylene, with 90% specificity in the solid state....
Imine cage molecules can be reduced to amines improve their chemical stability, but this introduces molecular flexibility. Hence, amine cages tend not exhibit permanent solid-state porosity. We report a synthetic strategy achieve shape persistence in by tying the vertices with carbonyls such as formaldehyde. Shape is predicted conformer stability calculations, providing design basis for strategy. The tied show enhanced porosity and unprecedented toward acidic basic conditions (pH 1.7-12.3),...
The separation of styrene (St) and ethylbenzene (EB) mixtures is important in the chemical industry. Here, we explore St EB adsorption selectivity two pillar-shaped macrocyclic pillar[n]arenes (EtP5 EtP6; n = 5 6). Both crystalline amorphous EtP6 can capture from a St-EB mixture with remarkably high selectivity. We show that be used to separate 50:50 v/v St:EB mixture, yielding single cycle purity >99%. Single-crystal structures, powder X-ray diffraction patterns, molecular simulations all...
Membranes with high selectivity offer an attractive route to molecular separations, where technologies such as distillation and chromatography are energy intensive. However, it remains challenging fine tune the structure porosity in membranes, particularly separate molecules of similar size. Here, we report a process for producing composite membranes that comprise crystalline porous organic cage films fabricated by interfacial synthesis on polyacrylonitrile support. These exhibit ultrafast...
Supramolecular synthesis is a powerful strategy for assembling complex molecules, but to do this by targeted design challenging. This because multicomponent assembly reactions have the potential form wide variety of products. High-throughput screening can explore broad synthetic space, inefficient and inelegant when applied blindly. Here we fuse computation with robotic create hybrid discovery workflow discovering new organic cage extension, other supramolecular systems. A total 78 precursor...
Abstract The influence of ligands on the spin state a metal ion is central importance for bioinorganic chemistry, and production base‐metal catalysts synthesis applications. Complexes derived from [Fe(bpp) 2 ] 2+ (bpp=2,6‐di{pyrazol‐1‐yl}pyridine) can be high‐spin, low‐spin, or spin‐crossover (SCO) active depending ligand substituents. Plots SCO midpoint temperature ( T ) in solution vs. relevant Hammett parameter show that low‐spin complex stabilized by electron‐withdrawing pyridyl (“X”)...
Electrochemically active covalent organic frameworks (COFs) are promising electrode materials for Li-ion batteries. However, improving the specific capacities of COF-based electrodes requires with increased conductivity and a higher concentration redox-active groups. Here, we designed series pyrene-4,5,9,10-tetraone COF (PT-COF) carbon nanotube (CNT) composites (denoted as PT-COFX, where
Abstract Covalent organic frameworks (COFs) are promising electrode materials for Li‐ion batteries. However, the utilization of redox‐active sites embedded within COFs is often limited by low intrinsic conductivities bulk‐grown material, resulting in poor electrochemical performance. Here, a general strategy developed to improve energy storage capability COF‐based electrodes integrating with carbon nanotubes (CNT). These COF composites feature an abundance...
The synthesis of three-dimensional (3D) covalent organic frameworks (COFs) requires high-connectivity polyhedral building blocks or the controlled alignment blocks. Here, we use latter strategy to assemble square-planar cobalt(II) phthalocyanine (PcCo) units into nbo topology by using tetrahedral spiroborate (SPB) linkages that were chosen provide necessary 90° dihedral angles between neighboring PcCo units. This yields a porous 3D COF, SPB-COF-DBA, with noninterpenetrated topology....
Abstract Here we report a two-step, hierarchical synthesis that assembles trigonal prismatic organic cage into more symmetric, higher-order tetrahedral cage, or ‘cage of cages’. Both the preformed [2+3] building blocks and resultant [4[2+3]+6]cage molecule are constructed using ether bridges. This strategy affords excellent hydrolytic stability is not feature common dynamic linkers, such as imines. Despite its relatively high molar mass (3,001 g mol −1 ), exhibits good solubility...
Abstract Proton conduction is a fundamental process in biology and devices such as proton exchange membrane fuel cells. To maximize conduction, three-dimensional pathways are preferred over one-dimensional pathways, which prevent two dimensions. Many crystalline porous solids to date show conduction. Here we report molecular cages with conductivities (up 10 −3 S cm −1 at high relative humidity) that compete extended metal-organic frameworks. The structure of the organic cage imposes pathway...
Gels can be formed by dissolving Fmoc-diphenylalanine (Fmoc-PhePhe or FmocFF) in an organic solvent and adding water. We show here that the choice amount of allows rheological properties gel to tuned. The differences arise from microstructure fibre network formed. then removed post-gelation, without significant changes properties. using acetone are meta-stable crystals FmocFF suitable for X-ray diffraction collected this gel.
Small structural changes in organic molecules can have a large influence on solid-state crystal packing, and this often thwarts attempts to produce isostructural series of crystalline solids. For metal-organic frameworks covalent frameworks, has been addressed by using strong, directional intermolecular bonding create families isoreticular Here, we show that an directing solvent, 1,4-dioxane, dominant effect the lattice energy for cage molecules. Inclusion dioxane directs packing these cages...
A number of Fmoc amino acids can be effective low molecular weight hydrogelators; we compare single crystal structures to fibre X-ray diffraction data.
New crystal forms of two well-studied organic molecules are identified in a computationally targeted way, by combining structure prediction with robotic crystallisation screen, including ‘hidden’ porous polymorph trimesic acid.
A molecular crystal of a 2-D hydrogen-bonded organic framework (HOF) undergoes an unusual structural transformation after solvent removal from the pores during activation. The conformationally flexible host molecule, ABTPA, adapts its conformation activation to initiate expansion. microcrystalline activated phase was characterized by three-dimensional electron diffraction (3D ED), which revealed that ABTPA uses out-of-plane anthracene units as adaptive anchors. These change orientation...