Ben Roberts

Our new video, created by Stuart Jantzen (Biocinematics), depicts the original Maxwell’s Demon thought experiment 😈 tinyurl.com/3ja25xfz, the archetypal information ratchet that inspires how we design molecular motors & pumps: tinyurl.com/msn8c2an; tinyurl.com/yj53rfvm; tinyurl.com/557vcubt 👹

Near-Quantitative Formation of Imines in Water with Allosteric Control We demonstrate the near-quantitative formation of an imine bond in water under physiologically relevant conditions using a stoichiometric ratio of aldehyde and amine. To overcome the low hydrolytic stability of imines in water, a complementary metal coordination bond between the amine and aldehyde monomers is introduced to enhance the thermodynamic stability of the imine. Imine bond formation is substrate-selective, tolerates the presence of a variety of functional groups, and produces imines that are stable in a broad pH range. We also show that the presence of a second metal-ion complex in the building blocks provides a regulatory handle to ‘switch on’ imine-bond formation using ATP as an external allosteric effector.

New paper published on the near-quantitative formation of imines in water !

with Tommaso Marchetti Lorenzo Goldin @benjaminoacid.bsky.social @deepaky25.bsky.social Federico Rastrelli and Luca Gabrielli

pubs.acs.org/doi/10.1021/...

#ChemSky

Chiral catalysis-driven rotary molecular motors - Nature Chemistry 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...

Out today in @natchem.nature.com 😃 Huakui, @stefanborsley.bsky.social @benjaminoacid.bsky.social & co illustrate why catalysis-driven motors (like motor proteins) can't use designs based on light-driven motors or molecules-that-rotate-through-multi-reaction-sequences www.nature.com/articles/s41...

When liquids freeze, ions normally grind to a halt — but not in our new materials!

Our latest paper in @science.org shows how organic salts can keep the same ionic conductivity mechanism as they transform from liquid to solid.

🔗 www.science.org/doi/10.1126/...

@ox.ac.uk @ajavestro.bsky.social

Interested in active transport, taxis, or light-driven systems?
Our latest work may catch your curiosity: shorturl.at/ApOse

A structurally simple molecule can transport multiple anions against their concetration gradiend (a form of phototaxis).
👇

Structure-performance relationships for catalysis-driven molecular machinery Molecular machine properties such as speed, efficiency, power, and torque depend upon particular features of structure, mechanism, and chemistry. The graphical abstract shows a Top Trumps-style representation of key performance indicators, illustrating how the first generation of synthetic catalysis-driven small-molecule machines compare with their biomolecular analogs. The understanding of how molecular machine design affects properties should aid technological advancements and a deeper understanding of the fundamental principles that link physics, chemistry, and biology.

Online now: Structure-performance relationships for catalysis-driven molecular machinery

In Search of Molecular Ratchets Triptycylhelicenes 1 and 2 were examined as molecular rachets (see picture) in which the triptycene serves as the rachet wheel (a) and the helicenes as pawl (b) and spring (c). The ease of rotation o...

My guess is that it was Kelly's work from the late 90s, doi.org/10.1002/anie... We've come a long way in understanding how molecular ratchets can work since then (just not as perpetual motion machines)

Chemistry involves such large and small numbers that it’s often hard to take in just how fast some processes occur. Dethreading a ring off the open end of a chain when there are no binding interactions present, or passing the end of one strand past another, are incredibly fast processes...

Photoswitchable Merocyanine‐Amphiphiles with Programmable Self‐Assembly Times A merocyanine-based amphiphile self-assembles in water to form visible-light-responsive ellipsoids that can be disassembled with visible light and reform abruptly ∼70 minutes after the light is switc...

We just published a photoswitchable amphiphile that abruptly assembles into ellipsoids over 1h after the light is switched off! #ozchem #ChemSky

chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/...

Huakui and Axel designed, made, and tested a new molecular motor to do this, or as Dave puts it

bsky.app/profile/prof...

This has been my main work during my post doc with @leonardprins.bsky.social based on experiments by Erica Del Grosso and Francesco Ricci and with theoretical support from @epenocchio.bsky.social

An information ratchet improves selectivity in molecular recognition under non-equilibrium conditions - Nature Nanotechnology An abiotic information ratchet mechanism increases selectivity for the correct DNA duplex from 2:1 at equilibrium to 6:1 under energy-dissipating conditions.

Information ratchets drive many molecular motors, but we can also use them for other nonequilibrium processes like performing error correction in a molecular recognition process to increase selectivity. Published today in @natnano.nature.com
www.nature.com/articles/s41...

'Ullo @jacs.acspublications.org, Hua-Kui, Axel, @benjaminoacid.bsky.social & @stefanborsley.bsky.social have gotta new motor! doi.org/10.1021/jacs...

In Situ Quantification of Directional Rotation by a Catalysis-Driven Azaindole-N-Oxide–Phenoic Acid Molecular Motor We report the in situ quantification of directional rotation of a new type of catalysis-driven rotary motor featuring a phenyl carboxylic acid rotor attached to a 7-azaindole-N-oxide stator through a biaryl C–N bond. Continuous directional rotation of the rotor about the stator is driven by the achiral motor’s rotary catalysis of carbodiimide hydration in the presence of a chiral pyrrolidinylpyridine-N-oxide. The catalytic cycle features an intermediate O-acyl-azaindole-N-oxide ester tether formed between the carboxylic acid of the rotor and the N-oxide of the stator. Face-selective cleavage of the tether by the chiral pyrrolidinylpyridine-N-oxide additive generates relatively long-lived diastereomeric pyridine-N-oxide esters of the phenyl carboxylic acid. These are hydrolyzed during the catalytic cycle to reform the carboxylic acid resting state of the motor, completing net directional 360° rotation. In contrast to previous catalysis-driven motor-molecules, the motor’s directionality could be determined directly from the transient concentrations of the diastereomeric intermediates formed during rotary catalysis. This avoids reliance on restricted rotation models to assess motor directionality and provides direct access to other key performance indicators such as motor speed and catalytic, coupling and fuel efficiency. The in situ-determined directionality of the motor was found to be in excellent agreement with the directionality determined from a restricted rotation model, supporting both the efficacy of the new approach and the validity of using appropriately designed restricted rotation models. The results establish a straightforward method for the in situ quantification of various aspects of motor behavior, aiding the design and optimization of artificial molecular motors.

Can you work out how fast a molecular motor rotates from in situ measurments? Turns out that yes, you can, as we show today in @jacs.acspublications.org
pubs.acs.org/doi/10.1021/...
@profdaveleigh.bsky.social @stefanborsley.bsky.social

People didn’t “used to be fine” without air conditioning during heat waves in the U.S. - a lot more people *just died*.

According to this study, air conditioning has cut heat deaths in the U.S. by around 80% since 1960.

papers.ssrn.com/sol3/papers....

OBR finds that its projection that Brexit would cost the country £40 billion have 'broadly materialised'.

Project Here.

(1/4)🚨 Ecstatic to share that Max’s work on #photoswitchable #metallo-supramolecular helicates, with #self-sorting, a #MolecularRatchet and #out-of-equilibrium structures, is now out in @angewandtechemie.bsky.social

👀 doi.org/10.1002/anie...
#ProudPI
#SupramolecularChemistry
#ChemSky
#WomenInSTEM

We are looking for a postdoctoral researcher to work on a project funded by the Boehringer Ingelheim Foundation on dynamic peptide self-assembly.

📄 Full position ad:
bit.ly/4jAIrmg

📅 Application deadline: May 31, 2025

#Postdoc #ChemistryJobs #SystemsChemistry #AcademicJobs #Freiburg #livMatS

Supramolekulare Chemie | Gesellschaft Deutscher Chemiker e.V.

Supramolecular chemistry has officially "grown up" in Germany. On behalf of the 10-person Founding Team👇, I am happy to announce the creation of section SupraChem within the German Chemical Society! 🍾 GDCh members please consider joining asap via www.gdch.de/suprachem @gdch.bsky.social

Etats-Unis : un chercheur français refoulé pour avoir exprimé « une opinion personnelle sur la politique menée par l’administration Trump » Le ministre de la recherche a dit sa « préoccupation », mercredi, après cette décision des autorités américaines. Le chercheur du CNRS aurait subi un contrôle aléatoire à son arrivée, avant que son or...

French researcher, going to a conference in Houston, was forbidden entry to US; his work and personal electronics were both confiscated.

Why? Because a “random search” of his cell phone revealed a negative personal opinion on Trump and the Trump administration. www.lemonde.fr/internationa...

Thinking about a revolution Some things are changing rather fundamentally and the way we think should perhaps change too

NEW

By me

Thinking about a revolution

Some things are changing rather fundamentally and the way we think should perhaps change too

Includes Monty Python, Yeats, and C.S.Lewis

Substack: emptycity.substack.com/p/thinking-a...

Personal blog: davidallengreen.com/2025/03/thin...

There is a PhD position available in my group at TU Delft (Dep. of Chemical Engineering) in (photo)electrochemical synthesis using supramolecular materials. 🧪 ☀️

🔗 More information on the position can be found here: careers.tudelft.nl/job/Delft-Ph...
⏰ Deadline: 11 March 2025.

⏰Only 1 more week left to apply for the PhD position (Photo)electrochemical synthesis within my group at TU Delft, Chemical Engineering! 🧪🔅

Structural Influence of the Chemical Fueling System on a Catalysis-Driven Rotary Molecular Motor Continuous directionally biased 360° rotation about a covalent single bond was recently realized in the form of a chemically fueled 1-phenylpyrrole 2,2′-dicarboxylic acid rotary molecular motor. However, the original fueling system and reaction conditions resulted in a motor directionality of only ∼3:1 (i.e., on average a backward rotation for every three forward rotations), along with a catalytic efficiency for the motor operation of 97% and a fuel efficiency of 14%. Here, we report on the efficacy of a series of chiral carbodiimide fuels and chiral hydrolysis promoters (pyridine and pyridine N-oxide derivatives) in driving improved directional rotation of this motor-molecule. We outline the complete reaction network for motor operation, composed of directional, futile, and slip cycles. Using derivatives of the motor where the final conformational step in the 360° rotation is either very slow or completely blocked, the phenylpyrrole diacid becomes enantiomerically enriched, allowing the kinetic gating of the individual steps in the catalytic cycle to be measured. The chiral carbodiimide fuel that produces the highest directionality gives 13% enantiomeric excess (e.e.) for the anhydride-forming kinetically gated step, while the most effective chiral hydrolysis promoter generates 90% e.e. for the kinetically gated hydrolysis step. Combining the best-performing fuel and hydrolysis promoter into a single fueling system results in a 92% e.e.. Under a dilute chemostated fueling regime (to avoid N-acyl urea formation at high carbodiimide concentrations with pyridine N-oxide hydrolysis promoters), the motor continuously rotates with a directionality of ∼24:1 (i.e., a backward rotation for every 24 forward rotations) with a catalytic efficiency of >99% and a fuel efficiency of 51%.

Check out how we made a minuscule motor rotate 24 times in one direction on its own! Huge thanks to all involved, especially @profdaveleigh.bsky.social for making this work possible
@pubs.acs.org
Huakui, Axel, @stefanborsley.bsky.social @benjaminoacid.bsky.social & Alex
pubs.acs.org/doi/10.1021/...

Wow, it really is 5 years already isn't it?

The position will be funded starting this summer by the CataLight consortium (www.catalight.uni-jena.de) relating photocatalysis with nonequilibrium systems chemistry and will involve organic and physical organic chemistry and soft matter aspects.

I’m excited to share that I will be moving to the University of Ulm as a junior group leader and I have a fully-funded open PhD position co-supervised by me and Max von Delius @mvdelius.bsky.social . Apply at benjamin.roberts@unipd.it, any shares would be appreciated!

www.bmwrlab.com/work-with-us

Scientific institutions have a long history of anticipatory obedience Societies should learn from this and speak up to support inclusion

I have run out of patience with the apparent silence of most US science institutions (and not just US) in the face of Trump & Musk's rampage. There are of so many facets of that, but in this column for @chemistryworld.com I talk about the assaults on inclusion.
www.chemistryworld.com/opinion/scie...

Wikipedia is a great achievement of our era, and (of course) it’s under attack by the far right. If you use it frequently like I do, consider donating: donate.wikimedia.org/w/index.php?...