Zach Wickens

Dreams really do come true 🎊 I'm extremely excited to be joining the University of Vermont this fall as a Tenure-track Assistant Professor in Chemistry!

Ferrioxalate photocatalysis: A multitasking platform for reductive iron catalysis Iron’s abundance motivates its use in sustainable catalyst systems that also offer complementary reactivity manifolds compared to precious metals. However, the challenging reduction of benchmark iron ...

After >3 years on the making, we are very excited to introduce Ferrioxalate Photocatalysis in a work published today in
@science.org :
science.org/doi/10.1126/...
A thread below (1/5) 👇

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ACS Board approves 112 new PRF grants The fall 2025 grants total $12,475,000 in researcher investments

The Panetti Lab officially has funding! Thank you to the ACS PRF for funding our work looking into CO2 functionalization with light. cen.acs.org/acs-news/pro...

Effective Recycling Pathways of Commodity Polymers Enabled by Mechanoradical Capture Plastics pervade every aspect of modern life, yet effective mechanical recycling remains a major challenge. This is, in part, because of the mechanical forces that are involved in reprocessing, which break polymer chains and generate mechanoradicals, leading to a reduction in molecular weight and diminished material properties. This work introduces a robust strategy to capture and redirect these reactive intermediates, enabling value-preserving recycling pathways for widely used polymers polystyrene (PS) and poly(methyl methacrylate) (PMMA). By employing ball milling to induce chain scission, we demonstrate that mechanoradicals can be trapped by bis(butyl trithiocarbonate), yielding polymers with trithiocarbonate (TTC) end groups. Polymers degraded via ball milling showed significant reduction in molecular weight, ≈90% lower than the pristine polymers. These low molecular weight, TTC-functionalized polymers then served as macroinitiators for light-mediated controlled polymerization or, in the case of PMMA, as mediators for depolymerization under mild conditions. Chain extension of the degraded materials led to restored or increased molecular weight compared to the pristine polymers. Shear oscillatory rheology experiments revealed a recovery of entangled polymer properties, as evidenced by the reappearance of the rubbery plateau. We further showed that this “capture-and-repair” strategy is compatible with multiple cycles of degradation and chain extension, achieving repeated molecular weight recovery over three cycles. Additionally, we found that ball milling alone lowers the thermal depolymerization temperature of PMMA, enabling up to ≈44% depolymerization at 220 °C. Together, these findings highlight mechanoradical capture as a promising strategy to both enhance circularity and improve overall performance of mechanically recycled plastics.

Very excited to share our recent article in JACS where we showed that we could capture mechanoradicals formed during polymer degradation and use them to grow polymers back to high MWs or prime them for depolymerization! pubs.acs.org/doi/10.1021/...

Congratulations Pete, Zach, and team!

Stereo-reversed E2 unlocks Z-selective C–H functionalization The stereoselective functionalization of C–H bonds represents a central challenge in modern organic synthesis. Despite decades of innovation in C–H activation chemistry, methods for Z-selective functi...

In @science.org this week @zachwickens.bsky.social and collaborators find a way to do Z-selective elimination using thianthrenium chemistry in a versatile route to Z olefins.

chemsky 🧪

www.science.org/doi/10.1126/...

Photoinduced double charge accumulation in a molecular compound - Nature Chemistry The photoinduced accumulation of redox equivalents is a challenging requirement for artificial photosynthesis. Now a molecule has been developed in which the sequential absorption of photons results i...

New molecular design absorbs 2 photons to store 2 positive and 2 negative charges

100 ns lifetime, 3 eV energy storage, and 37% quantum yield

A step toward multi-electron photochemistry

Mathis Brändlin and @bjoernpfund.bsky.social in @natchem.nature.com

www.nature.com/articles/s41...

Efficient super-reducing organic photoredox catalysis with proton-coupled electron transfer mitigated back electron transfer Photoredox catalysis driven by visible light has improved chemical synthesis by enabling milder reaction conditions and unlocking distinct reaction mechanisms. Despite the transformative impact, visib...

Congrats to Amreen and Arindam and the whole team on getting their work out in Science today!! www.science.org/doi/10.1126/...

Congrats to SuPRCats Prof. Zach Wickens (@zachwickens.bsky.social) for being selected as a Dreyfus Teacher-Scholar for 2025 and Prof. Garret Miyake (not-on-bluesky) for being selected for CSU's scholarship impact award! Check out the details below!

I’m thrilled to share that I will be joining the Department of Chemistry at the University of Rochester as an Assistant Professor!

Group photo of Chancellor Mnookin and Provost Isbell with 11 Distinguished Teaching Award Recipients in front of a red Wisconsin crest backdrop.

Chancellor Mnookin, DTA awardee Paul Barford, DTA awardee Amy Trowbridge, and Rep. Renuka Mayadev smiling in front of a Wisconsin crest backdrop.

Chancellor Mnookin, Robby Abrahamian (chief of staff to Sen. Jodi Habush-Sinykin), Rep. Deb Andraca, and DTA Awardee Paul Roback smiling in front of a red Wisconsin crest backdrop.

Chancellor Mnookin and Rep. Renuka Mayadev on either side of DTA awardee Claus Elholm Andersen's wife smiling in front of a red Wisconsin crest backdrop.

Our faculty are INCREDIBLE teachers — and tonight we celebrated our 12 Distinguished Teaching Award winners. Thank you for inspiring curiosity & preparing our students to lead lives of purpose in the proud tradition of the Wisconsin Idea! Read more: news.wisc.edu/meet-the-202...

Amazing to see 🇨🇦 representation from @chemuoft.bsky.social @alexgabbey.bsky.social and Francisco Yarur Villanueva. Congrats to all and welcome to the Future Leaders family!! 🤗

Thrilled to announce our incredible speaker lineup for the 2025 #ETOC Online Symposium! 📢 Join us on April 9-10 from 15:00 to 19:00 (CET).🗓️ Secure your spot today by signing up through the link below! Don't miss this exciting event! uva-live.zoom.us/webinar/regi... (1/4)

Our latest @angewandtechemie.bsky.social paper!🎉 We introduce a 2-stage dication pool strategy for the anti-Markovnikov hydrofunctionalization of alkenes via thianthrenium intermediates, expanding the scope of nucleophiles. Huge congrats to @sbencee.bsky.social & the team!👏
doi.org/10.1002/anie...

Influence of Dihydrophenazine Photoredox Catalyst Excited State Character and Reduction Potentials on Control in Organocatalyzed Atom Transfer Radical Polymerization The development of N,N-diaryl dihydrophenazine organic photoredox catalysts (PCs) has enabled numerous examples of organocatalyzed atom transfer radical polymerization (O-ATRP) of methyl methacrylate (MMA) monomer to polymers with low dispersity (Đ < 1.30) and near-unity initiator efficiency (I* ∼ 100%), as well as small molecule synthesis. In this work, we investigate the influence of core substitution (CS) by alkyl, aryl, and heteroatom groups on singlet excited state reduction potential (ES1°*). We observe that a highly reducing ES1°* is in part a result of a locally excited (LE)-dominated hybridized local and charge transfer (HLCT) excited state in CS PCs, which is influenced by the identity of the core substituent. Additionally, the PCs that possess a LE-dominated HLCT character maintain a relatively oxidizing PC radical cation oxidation potential (E1/2) for deactivation in O-ATRP compared to fully LE PCs reported in prior work. For example, a thiophenol core substituted (heteroatom CS, HetCS) PC shows the most negative ES1°* (−2.07 V vs SCE), more LE character (Stokes shift = 124 nm), and has an oxidizing PC radical cation (E1/2 = 0.30 V vs SCE). The CS PCs with improved properties, including more negative ES1°*, perform best in O-ATRP of MMA with the HetCS PC showing the best control in both DMAc (Đ = 1.08, I* = 89%) and EtOAc (Đ = 1.06, I* = 97%). Additionally, the HetCS PC was found to mediate the controlled polymerization of n-butyl acrylate (n-BA) (Đ = 1.24, I* = 97%), which has remained challenging in O-ATRP without supplemental deactivation strategies. An aryl CS PC was found to have moderate control as low as 1 ppm PC, indicating facilitation of low PC loadings (Đ = 1.33, I* = 69%). The relationship between excited state character, ES1°*, and polymerization control observed in this work provides a foundation for increasing the utility of phenazine PCs across photoredox catalysis.

Congrats to former SuPRCat-er and recent grad Katrina on her publication in ACS Catalysis! pubs.acs.org/doi/10.1021/...

a cartoon says hey everybody an old man 's talking while bart simpson looks on ALT: a cartoon says hey everybody an old man 's talking while bart simpson looks on

Bluetorial: Women, courage, and leadership

What follows will include some generalizations based on population averages of what I have experienced over the course of my career. There are, of course, exceptions in every group who are substantially more to one extreme or the other.

STAND UP FOR SCIENCE March 7, 2025. Washington DC and nationwide. Because science is for everyone.

Nationwide #standupforscience protest and campus/workplace walkouts March 7 at noon.
If you can't make it to your state capital JUST WALK OUT
standupforscience2025.org

standupforscience2025.org/organize-a-s...

Galileo affair - Wikipedia

Today in Science history:

1616 – Galileo Galilei is formally banned by the Roman Catholic Church from teaching or defending the view that the earth orbits the sun.

Brought to you by American Science!

Don't forget that the lead compound for vertex came from a library developed in collaboration with the Jin Quan Yu lab at Scripps, using CH functionalization

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

Grateful to the Sloan Foundation for their support of fundamental chemistry research in this challenging time for our scientific community!

People who voted Trump who are feeling pissed off right now about broken promises are an organizing opportunity, not a gloating opportunity

Save NIH and NSF Research Funding ⭑ 5 Calls On February 7, the Trump administration moved to cut billions of dollars in funding from the National Institutes of Health (NIH) and National Science …

A useful tool and a great thing to do...

5calls.org/issue/nih-ns...

8 years ago @asbmb.bsky.social gave me +18 more trainees a crash course in advocacy for their DC Hill Day. With NIH slashing indirect costs effective immediately, university Govt Affairs teams will be swamped. Here's 10 tips for scientists contacting lawmakers +pics from Denver's 2017 Science March.

Unified Hydrogen Atom Transfer Approach To Construct Vicinal Functionality Due to their prevalence in pharmaceuticals and natural products, vicinally functionalized motifs are highly sought-after. Traditionally, these fragments are synthesized from alkene precursors via oxidation reactions. However, complementary syntheses via a C–C bond-forming approach are underexplored. Herein, we disclose a unified approach for accessing these motifs by acetal reagents made from affordable, prefunctionalized starting materials. We have demonstrated the wide applicability of this methodology to a variety of molecularly complex substrates. Additionally, the coupled products can be employed in one-pot cyclizations to synthesize a variety of lactones.

Daniel Kim at Temple and his team with a super useful general approach to heteroatom dyad introduction

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

Science on Tap yesterday was a hit! Congrats to Ally and Jess for sharing their work with our community!

Excited Organic Radicals in Photoredox Catalysis Many important synthetic-oriented works have proposed excited organic radicals as photoactive species, yet mechanistic studies raised doubts about whether they can truly function as photocatalysts. This skepticism originates from the formation of (photo)redox-active degradation products and the picosecond decay of electronically excited radicals, which is considered too short for diffusion-based photoinduced electron transfer reactions. From this perspective, we analyze important synthetic transformations where organic radicals have been proposed as photocatalysts, comparing their theoretical maximum excited state potentials with the potentials required for the observed photocatalytic reactivity. We summarize mechanistic studies of structurally similar photocatalysts indicating different reaction pathways for some catalytic systems, addressing cases where the proposed radical photocatalysts exceed their theoretical maximum reactivity. Additionally, we perform a kinetic analysis to explain the photoinduced electron transfer observed in excited radicals on subpicosecond time scales. We further rationalize the potential anti-Kasha reactivity from higher excited states with femtosecond lifetimes, highlighting how future photocatalysis advancements could unlock new photochemical pathways.

Excited organic radicals in photoredox catalysis

Our perspective just published in JACS Au:

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

Really excited to see this amazing work out in ChemRxiv from our #ChemCollab between the @uwyoongroup.bsky.social @tehshik.bsky.social and #PfizerChemistry
Photochem-mediated oxygen migration into sp3 bonds delivering small ring ethers as well as an OH - methylene transposition
#ChemSky 1/