The first chemically fueled small-molecule walker dances around a sugar molecule without falling off

The electronic music legend will play a special gig at Burlington House to celebrate 30 years of his debut album 'Better Living Through Chemistry'.

The proportion of one- and two-author papers in the Nature Index is shrinking rapidly, as science done by big teams continues to surge.

Motor proteins power everything from muscle contraction to bacterial swimming. While replicating their chemically fuelled directional motion in the laboratory has proved difficult, researchers are mak...

Motor proteins power everything from muscle contraction to bacterial swimming. While replicating their chemically fuelled directional motion in the laboratory has proved difficult, researchers are mak...

No need for metals or recognition sites to build these molecular machines

No need for metals or recognition sites to build these molecular machines

US research community mobilising to push back on proposed rule that would give apparatchiks control of which research gets funded

We report an efficient lanthanide-template synthesis of a conformationally switchable molecular trefoil knot assembled from three 2,6-bis(1,2,3-triazol-4-yl)pyridine (btp) ligand strands. Coordination of Lu3+ organizes three btp building blocks into a trimeric circular helicate that, upon subsequent ring-closing olefin metathesis, gives a trefoil knotted coordination complex in 73% yield over two steps. Subsequent demetalation with tetraethylammonium fluoride quantitatively affords the corresponding metal-free 87-atom-loop trefoil knot. The metal-coordinated and metal-free knots were characterized by NMR spectroscopy, high-resolution mass spectrometry, and single-crystal X-ray diffraction. The metalated and metal-free knots adopt substantially different conformations to each other, in both solution and the solid state. In the Lu3+-bound knot the btp units are directed inward to coordinate the metal center, with the strand conformation further stabilized by pyridine–naphthalene π-stacking. In the metal-free knot the btp motifs are rotated outward, with the conformation stabilized by triazole C–H···O hydrogen bonding and naphthalene–naphthalene π-stacking. Reversible metalation and demetalation cleanly interconverts the two knot conformations, establishing btp building blocks as a simple and versatile platform for responsive entangled or woven molecular topologies.

DSIT analysis on the economic and social benefits to the UK generated by public R&D investment.

Biological adaptive receptors are driven out of equilibrium to change the detectable range of analyte concentrations. Here, a chemically fueled rotaxane information ratchet couples Zn(II) binding to c...

Mayor of London says returning to EU now more desirable because of economic instability caused by Donald Trump Labour should go into the next general election promising to rejoin the EU, Sadiq Khan has said. The mayor of London has repeatedly made the case for joining the customs union and single market, but went much further on Wednesday night by suggesting the party should promise full membership at next ballot. Continue reading...

Ring-opening C–N bond cleavage reactions provide an effective means to convert widespread, readily accessible chiral N-heterocycles into hard-to-attain stereodefined linear amines. Current strategies either rely on the strain-induced release of small aziridine and azetidine rings or, for larger ring systems, require highly electrophilic reagents, oxidative conditions, or preinstalled reactive functionalities to enable the ring-opening event. Recently, complementary radical strategies that exploit the reactivity of α-amino-ketyl radicals, formed upon single-electron transfer (SET) reduction of common N-carbonyl protecting groups, have emerged. Nevertheless, these methods facilitate the homolytic fragmentation only of up to 5-membered azacycles. In this study, we leveraged electroreductive conditions to switch the nature of the above C–N bond cleavage manifold from radical to ionic and enable the heterolytic ring-opening of a broad array of unstrained cyclic amines (comprising pyrrolidines, piperidines, azepines, azocanes, and N-macrocycles), protected as N-(thio)amides, carbamates, or ureas. Crucially, this electrochemically enabled reactivity switch grants complementary functional group compatibility and a broader ring size and N-carbonyl group scope. Computational and experimental studies indicate that electrochemical settings are crucial for generating the Mg(II)-Lewis acid catalyst, activating the N-carbonyl moiety while prompting the so-formed oxy-iminium ion intermediates to undergo two consecutive cathodic SET reductions, generating “umpoled” α-amino-α-oxy-carbanion species. These, via irreversible E1cB fragmentation of the adjacent C–N bond, lead to the desired ring-opened products. Our electrochemical procedure can be scaled up and miniaturized (enabling its application to high-throughput experimentation screening), and its synthetic utility has been demonstrated by accessing decorated stereodefined linear amides from stereochemically rich pyrrolidine and azepane derivatives.

The structural anisotropy necessary for the powered directional rotation of chemically fuelled molecular motors had previously been provided by chiral fuels or enzymes. Now it has been shown that asym...