News

Free radicals@MOFs

Metal-organic frameworks (MOFs) decorated with stable organic radicals are highly promising materials for redox catalysis. Unfortunately however, the synthesis of chemically robust MOFs typically requires harsh solvothermal conditions, which are not compatible with organic radicals. Here we describe the synthesis of two isoreticular families of stable, mixed-component, zirconium MOFs with UiO-66 and UiO-67 structure and controlled amounts of covalently attached TEMPO radicals. The materials were obtained using a relatively low-temperature, HCl-modulated de novo method developed by Hupp and Farha and shown to contain large amounts of missing cluster defects, forming nanodomains of reo phase with 8-connected clusters. In the extreme case of homoleptic UiO-67-TEMPO(100%), the material exists as an almost pure reo phase. Large voids due to missing clusters and linkers allowed these materials to accommodate up to 2 times more of bulky TEMPO substituents than theoretically predicted for the idealized structures and proved to be beneficial for catalytic activity. The TEMPO-appended MOFs were shown to be highly active and recyclable catalysts for selective aerobic oxidation of a broad range of primary and secondary alcohols under exceptionally mild conditions (RT, atmospheric pressure of air). The influence of various parameters, including pore size and TEMPO content, on the catalytic activity was also comprehensively investigated.

Graphical Abstract - ACS AMI 2017

Deamination of MOFs

A versatile method for the post-synthetic removal of primary amino groups from metal-organic frameworks (MOFs) has been developed. The method allowed the first successful synthesis of the missing parent compound of an important family of MOFs – the unsubstituted (Al)MIL-101. The material was shown to be a useful reference compound for the elucidation of the role of amino groups in the adsorption and deactivation of olefin metathesis catalysts. The chemoselectivity of the deamination is sufficient for the selective removal of NH2 substituents from mixed-linker MOFs bearing both NH2 and RCONH groups.

Graphical Abstract - ChemComm 2017

Two new papers: in OBC and in Electrochimica Acta

Joining together two diamidocarbazole moieties with a flexible linker led to a selective fluorescent sensor for an extremely hydrophilic sulfate anion, which works even in the presence of 25% of water! It allowed sulfate detection in real world samples, such as mineral waters, which contain many other anions. See more.

Graphical Abstract - OBC 2017

Diaminocarbazole was also used to construct a new catalytic system, composed of bimetallic Au@Pt nanoparticles dispersed in a conducting polymer. Our new organic-inorganic hybrid system shows enhanced activity towards formic acid electrooxidation. See more.

Metathesis@MOFs in ACS Catalysis!

Despite their record-braking sorption capacities, metal−organic frameworks (MOFs) have rarely been used for the immobilization of homogeneous catalysts by simple absorption from solution. Here we demonstrate that this simple strategy allows the first successful immobilization of olefin metathesis catalysts inside MOFs. Ruthenium alkylidene complexes bearing ammonium-tagged NHC ligands were successfully supported inside (Al)MIL-101-NH2·HCl. The materials thus obtained are true heterogeneous catalysts, active toward various substrates with TONs up to 8900 (in batch conditions) or 4700 (in continuous flow). Although the catalysts were held inside the MOF by noncovalent forces only, leaching was not observed and heavy metal contamination of the products was found to be below the detection limit of ICP MS (0.02 ppm). The robustness of the catalyst attachment allowed their use in a continuous flow setup.

Graphical Abstract - ChemComm 2015

Our first MOF paper has just appeared in ChemComm!

In our fist MOF paper we have described the first post-synthetic protection/deprotection method suitable for amino MOFs.

Graphical Abstract - ChemComm 2015

Welcome to the new Team member!

Dr Nicolai Nikishkin dołączył do naszego Zespołu po rekrutacji do projektu IDEAS PLUS. Witamy na pokładzie! Zobacz zdjęcia.Nicolai Nikishkin, PhD joined the group following recruitment to the IDEAS PLUS project. Welcome aboard! See pictures.

Sulfate anion is a pH-switchable template

SO42- is one of the priviledged anionic templates for the synthesis of catenanes, rotaxanes and other complex structures. Now we demonstrate that it can be “switched off” simply by protonation.
Graphical Abstract - EurJOC 2015

Positions available!

Several MSc, PhD and Postdoc positions are available at the moment. We also generally welcome temporary visitors.

If you are enthusiastic about our research and want to join our group, please send your CV, a one-page letter of motivation and contact details of two academic referees by email to Michal Chmielewski.

Applicants for MSc and PhD positions should also provide the transcripts of the marks received for their undergraduate and graduate degrees (for as far as completed).

Job offer for postdoctoral researchers within the grant IDEAS PLUS (in Polish)

Multivalency by self-assembly: postdoctoral work with Jean-Marie Lehn in Chem. Eur. J

Multiplication of functional units by self-assembly is a powerful way to new properties and functions. Self-organisation of components decorated with recognition groups leads to multivalent entities, amenable to strong and selective binding with multivalent targets, such as protein receptors. In this paper we describe an efficient, supramolecular, one-pot valency multiplication process proceeding through self-organisation of monovalent components into well-defined, grid-shaped [2×2] tetranuclear complexes bearing eight sugar residues for multivalent interaction with the tetrameric lectin, concanavalin A.
Concanavalin A