Andrea Laybourn

Porous, Fluorescent, Covalent Triazine-Based Frameworks Via Room-Temperature and Microwave-Assisted Synthesis

Porous, fluorescent, covalent triazine-based frameworks (CTFs) are obtained in an unprecedentedly mild reaction, opening up a scalable pathway for molecular building blocks previously thought incompatible with this chemistry. Choice of monomers and synthetic conditions determines the optical properties and nano-scale ordering of these highly microporous materials with BET surface areas exceeding 1100 m(2) g(-1) and exceptional CO(2) capacities (up to 4.17 mmol g(-1)).

Metal–Organic Conjugated Microporous Polymers

Zwei vielseitige Strategien fur die Herstellung von Metall-organischen konjugierten mikroporosen Polymeren (MO-CMPs) mit Metallen wie Rhenium, Rhodium und Iridium werden beschrieben (siehe Beispiel). Diese Materialien vereinen in sich zwei Merkmale: eine ausgedehnte, unterbrechungsfreie elektronische Konjugation und das Vorhandensein katalytisch aktiver Metallzentren

Triazine‐Based Graphitic Carbon Nitride: a Two‐Dimensional Semiconductor

Graphitic carbon nitride has been predicted to be structurally analogous to carbon-only graphite, yet with an inherent bandgap. We have grown, for the first time, macroscopically large crystalline thin films of triazine-based, graphitic carbon nitride (TGCN) using an ionothermal, interfacial reaction starting with the abundant monomer dicyandiamide. The films consist of stacked, two-dimensional (2D) crystals between a few and several hundreds of atomic layers in thickness. Scanning force and transmission electron microscopy show long-range, in-plane order, while optical spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations corroborate a direct bandgap between 1.6 and 2.0 eV. Thus TGCN is of interest for electronic devices, such as field-effect transistors and light-emitting diodes.

Functional conjugated microporous polymers: from 1,3,5-benzene to 1,3,5-triazine

Conjugated microporous polymers (CMPs) based on the electron-withdrawing 1,3,5-triazine node (TCMPs) were synthesized by palladium-catalyzed Sonogashira-Hagihara cross-coupling. The porosity in these polymers was found to be comparable to the analogous 1,3,5-connected benzene CMP systems that we reported previously, demonstrating that nodes can be substituted in these amorphous materials in a rational manner, much as for certain crystalline porous metal–organic frameworks. The CO2 adsorption properties of the TCMPs were measured and compared with the corresponding CMPs, and it was found that the TCMP networks adsorbed more CO2 than CMP analogues with comparable BET surface areas. Network TNCMP-2 showed the highest surface area (995 m2 g−1) and a CO2 uptake of 1.45 mmol g−1 at 1 bar at 298 K. The band gap in these triazine-based CMPs could also be engineered through copolymerization with other functional monomers.

Microporous copolymers for increased gas selectivity

Microporous organic polymers have been synthesised from aniline using Friedel–Crafts alkylation. Networks synthesised solely from aniline were non-porous to nitrogen. However, co-polymerisation with benzene resulted in networks with apparent Brunauaer-Emmett-Teller (BET) surface areas up to 1100 m2 g−1. Increased aniline content in the hyper-crosslinked networks led to improved CO2/N2 selectivity, suggesting a strategy for the design of materials for post-combustion carbon capture.

Branching out with aminals: microporous organic polymers from difunctional monomers

Microporous organic polymers (MOPs) have been prepared via one-pot polycondensation reactions between aldehydes and amines. Primary amines were reacted with imines to produce porous polymers from A2 + B2 monomer combinations. The resulting networks exhibit BET surface areas in the range 500–600 m2 g−1. This approach opens up the possibility of synthesising MOPs using readily-available and inexpensive precursors.

A Metal−Organic Framework with a Covalently Prefabricated Porous Organic Linker

We report here the synthesis of a metal-organic framework comprising an organic cage linker with covalently prefabricated, intrinsic porosity. The network can be compared to a porous rock salt structure where the pores are partially filled by charge-balancing cations.

Network formation mechanisms in conjugated microporous polymers

We discuss in detail the mechanism of formation of a highly microporous polymer, CMP-1, formed mainly via Sonogashira–Hagihara coupling. We demonstrate how the microporosity evolves with time, and discuss the importance of alkyne homo-coupling on the microporosity.

Metal–organic frameworks in seconds via selective microwave heating

Synthesis of metal–organic framework (MOF) materials via microwave heating often involves shorter reaction times and offers enhanced control of particle size compared to conventional heating. However, there is little understanding of the interactions between electromagnetic waves and MOFs, their reactants, and intermediates, all of which are required for successful scale-up to enable production of commercially viable quantities of material. By examining the effect of average absorbed power with a constant total absorbed energy to prepare MIL-53(Al) we have defined a selective heating mechanism that affords control over MOF particle size range and morphology by altering the microwave power. This is the first time a selective mechanism has been established for the preparation of MOFs via microwave heating. This approach has been applied to the very rapid preparation of MIL-53(Al)ta (62 mg in 4.3 seconds) which represents the fastest reported synthesis of a MOF on this scale to date.