Roland Roesler
rolandroesler.bsky.social
Roland Roesler
@rolandroesler.bsky.social
Synthetic inorganic and organometallic chemistry at the University of Calgary.
Reposted by Roland Roesler
Check out our latest contribution in @jacs.acspublications.org, moved forward by Oscar Kelly

doi.org/10.1021/jacs...

With Brendan Twamley and @fenicu.bsky.social

Cc @iqccudg.bsky.social
Electrostatic Fields Induce Accelerated Proton Coupled Electron Transfer Rates in Chlorophyll Model Compounds
Chlorophyll-based pigments are crucial mediators of redox processes in photosynthesis, serving as the primary electron donors in photosystems I and II. Despite their structural similarities, these pigments exhibit a wide range of redox potentials (0.5–1.3 V vs SHE), and little experimental insight into the origins of this variation is available. To address this deficit, we have synthesized two crown ether-appended Mg-porphyrin complexes as chlorophyll model compounds and demonstrated their ability to bind redox-inactive metal cations. Cation binding to the Mg-porphyrin complexes was found to increase their redox potentials in a manner that depends linearly on the total cationic charge felt by the complex, implicating a through-space electrostatic field effect. The corresponding 1-electron oxidized π-cation radical complexes were then prepared and characterized by UV–vis, FT-IR, and EPR spectroscopies and ESI-MS. The π-cation radical species were found to be competent for the PCET oxidation of a phenolic substrate, mimicking the reaction between photo-oxidized chlorophyll and tyrosine in photosystem II. Cation binding to the π-cation radical complexes was found to increase the rates of their PCET and ET reactions in a charge-dependent manner which could be rationalized using Marcus theory. This work provides direct experimental evidence that electrostatic fields can tune the redox potentials of chlorophyll model compounds, leading to an increase in their oxidative reactivity.
doi.org
August 1, 2025 at 3:47 PM
Reposted by Roland Roesler
What is the difference between chemical equivalence and magnetic equivalence? u-of-o-nmr-facility.blogspot.com/2008/08/chem... #nmr #nmrchat #chemsky
June 22, 2025 at 9:40 AM
Reposted by Roland Roesler
A new budget plan would kill two CDC journals, while a U.S. prosecutor accuses some nongovernmental publications of being “partisans.”
Trump administration targets academic journals with attorney letter, proposed funding cuts
Budget plan would kill two CDC journals, while U.S. prosecutor accuses some nongovernmental publications of being “partisans”
scim.ag
April 18, 2025 at 9:27 PM
Reposted by Roland Roesler
Pleased to share our chapter in @springernature.com book Structure & Bonding on "Geometrically Constrained Bismuth Compounds". Co-written with recent MSc Tamina @taminazk.bsky.social. Many thanks to reviewers + ed. Crispin Lichtenberg!
link.springer.com/chapter/10.1...
@dalchemistry.bsky.social
Geometrically Constrained Bismuth Compounds
A major thrust of research in modern main group chemistry is the use of multidentate ligands to perturb geometries at p-block elements such that they deviate substantially from valence shell electron-...
link.springer.com
April 15, 2025 at 2:01 PM
Reposted by Roland Roesler
www.harvard.edu
April 14, 2025 at 5:57 PM
Reposted by Roland Roesler
Conjugated-Length-Dependent Self-Assembly, Host–Guest Binding, and Photoreactivity of Thienoacene Ribbons

doi.org/10.31635/ccs...
April 5, 2025 at 7:58 AM
Reposted by Roland Roesler
Dr. Mark MachLachlan has been appointed as Dean of the Faculty of Science for a five-year term, commencing April 1, 2025.

academic.ubc.ca/academic-com...
March 31, 2025 at 4:22 PM
Reposted by Roland Roesler
Book on NMR Crystallography is finally out today!

"Modern NMR Crystallography: Concepts and Applications"

#NMRchat
@uottawascience.bsky.social

@rsc.org

doi.org/10.1039/9781...

Thanks to all authors for their hard work and patience!
Modern NMR Crystallography: Concepts and Applications
NMR crystallography has blossomed as a focussed field of research in recent years and is now acknowledged as such by the International Union of Crystallogr
doi.org
March 31, 2025 at 11:58 AM
Reposted by Roland Roesler
Dicationic Boron Derivatives of Schlenk’s and Thiele’s Hydrocarbon | Journal of the American Chemical Society @jacs.acspublications.org @pubs.acs.org

pubs.acs.org/doi/full/10....
Dicationic Boron Derivatives of Schlenk’s and Thiele’s Hydrocarbon
In recent years, neutral NHC-stabilized boryl radicals have been investigated as reactive species in various organic transformations. However, cationic boron radicals have been significantly less explored. In addition, boron-centered open-shell species with S > 1/2 have emerged as attractive synthetic targets. In this study, we provide a synthetic route to an NHC-stabilized boryl radical cation as a salt of the weakly coordinating [Al(ORF)4]− (RF = C(CF3)3) anion. The synthetic procedure was extended to dicationic diboron derivatives of Schlenk’s and Thiele’s hydrocarbons with meta- and para-phenylene coupling units between the spin centers. While most known isolable boron biradicals have a singlet ground-state with a thermally accessible triplet state, the boron version of Schlenk’s hydrocarbon occupies a ground-state triplet spin-state, as shown by combined electron paramagnetic resonance spectroscopy and density functional theory studies. Furthermore, initial reactivity studies of the dications with elemental sulfur and diphenyldiselenide are presented.
pubs.acs.org
March 25, 2025 at 3:39 PM
Senior @ucalgary.bsky.social undergrad George Doerksen’s summer research at @helsinki.fi - supported by @mitacscanada.bsky.social and conducted with Petra Vasko and Timo Repo - is reported in @chemcomm.rsc.org.
pubs.rsc.org/en/content/a...
Metal-free alkene hydroboration with pinacolborane employing C6F5BH2·SMe2 precatalyst
We have developed C6F5BH2·SMe2 as a unique, metal-free precatalyst for alkene hydroboration. It combines high reactivity and excellent regio- and chemoselectivity. Mechanistic studies reveal that the ...
pubs.rsc.org
March 30, 2025 at 11:04 PM
"Chemistry Between the Stars" with @kavliprize.bsky.social laureate Ewine van Dishoeck, the 2025 ICI lecturer @ucpress.bsky.social
March 30, 2025 at 1:48 AM
The comeback of the complexes with "naked" group 15 ligands continues with some triple-decker heavyweights.
www.nature.com/articles/s41...
Synthesis of triple-decker sandwich compounds featuring a M–M bond through cyclo-Bi5 and cyclo-Sb5 rings - Nature Chemistry
Although several inorganic analogues of cyclopentadiene have been reported with group-15 elements, examples featuring the heavier elements Sb and Bi remain scarce. Now, a Bi5 ring has been stabilized ...
www.nature.com
March 22, 2025 at 3:43 PM
Reposted by Roland Roesler
Ingesting high levels of plastics can harm baby seabirds in unseen ways, affecting their blood, brains, and other organs, according to a new #ScienceAdvances study. scim.ag/4bJza91
Seabirds in crisis: Plastic ingestion induces proteomic signatures of multiorgan failure and neurodegeneration
Plastic consumption in seabirds causes blood signatures of widespread organ damage including brain, stomach, kidney, and liver.
scim.ag
March 20, 2025 at 1:51 PM
Reposted by Roland Roesler
Thrilled to share our latest work from the lab, in collaboration with @townrowresearch.bsky.social , exploring the fusion of heteroleptic amido-substituted stannylenes and NHCs! #chemsky www.nature.com/articles/s41... 1/2
Carbene-activated stannylenes to access selective C(sp3)–H bond scission at the steric limit - Nature Communications
The ubiquity of N-heterocyclic carbenes (NHCs) in chemical research typically arises from their potent stabilizing capabilities and role as innocent spectators to stabilize otherwise non-bottleable co...
www.nature.com
March 19, 2025 at 5:48 PM
Reposted by Roland Roesler
Come be our colleague! The University of Prince Edward Island is hiring a tenure track assistant professor in cleantech!
@chemjobber.bsky.social

www.upei.ca/hr/competiti...
Assistant Professor- Tenure Track Position- Department of Island Studies/Cleantech- Faculty of Arts *Amended closing date* | University of Prince Edward Island
The University of Prince Edward Island offers an amazing and affordable student experience in beautiful Charlottetown, PEI. Our interesting and unique programs bring out your best, lead you to realize...
www.upei.ca
March 18, 2025 at 11:08 AM
Reposted by Roland Roesler
To get around the jargon, imagine a knife that would cut through an apple but not a peeled banana🔪🍎🍌

In @science.org this week the Leonori and Ruffoni groups show photoexcitation of nitroarene reagents selectively cleaves aryl C=C bonds over olefins

chemsky 🧪

www.science.org/doi/10.1126/...
Excited-state configuration of nitroarenes enables oxidative cleavage of aromatics over alkenes
The ozonolytic deconstruction of aromatics remains a challenge in organic chemistry. Ozone preferentially reacts with alkenes over arenes, meaning that once the initial aromatic cleavage occurs, the d...
www.science.org
March 13, 2025 at 6:58 PM
Reposted by Roland Roesler
Ayu’s work on CN/NC-isomerism in Dioxophosphoranes is just out in Chem.Sci. Here we show that Cyanophosphides can be cleanly oxidized with O2, giving [ArPO2(CN)]-. Surprisingly both, cyanide and isocyanide form simultaneously! Super exited about this! @likat.bsky.social

pubs.rsc.org/en/content/a...
March 13, 2025 at 7:45 AM
Reposted by Roland Roesler
Is it a covalent bond? Is it a Lewis-pair? See my latest article with the Krossing group about the synthesis and characterization of the first heterodinuclear metal carbonyl cation [MnFe(CO)10]+ published in Chem. Eur. J. @chemistryeurope.bsky.social doi.org/10.1002/chem... @uni-freiburg.de
March 11, 2025 at 12:15 PM
Reposted by Roland Roesler
Our story on stabilizing the parent triplet titanocene with an NHC is out! Congratulations to the entire team – it's great to be back with some Group 4 chemistry!☺️ @daltontrans.rsc.org @townrowresearch.bsky.social #chemsky pubs.rsc.org/en/content/a...
Isolation of the parent triplet titanocene via NHC stabilisation
We present the synthesis and characterization of the parent isolable monomeric triplet titanocene complex, stabilized by the N-heterocyclic carbene (NHC) IMe4. Investigated by SQUID magnetometry and q...
pubs.rsc.org
March 6, 2025 at 2:35 PM
Reposted by Roland Roesler
Our ChemComm on anion transport on biologically relevant lipid mixtures is just out. The project was started by placement student Sarah Rooijmans from @unigroningen.bsky.social and finished by visitor Krystyna Maslowska-Jarzyna. Many congrats to all involved! pubs.rsc.org/en/content/a...
Anion transport in biologically relevant lipid mixtures
A potent squaramide-based anion transporter was used to evaluate how vesicles prepared with tailored lipid compositions, which mimic organelle membranes, can impact transmembrane transport. Using HPTS...
pubs.rsc.org
February 17, 2025 at 3:37 PM
Reposted by Roland Roesler
Reposted by Roland Roesler
Florida State University chemist Rob Schurko, director of the NMR and MRI Facility @nationalmaglab.bsky.social elected to prestigious society for advancing magnetic resonance, supporting next generation of scientists news.fsu.edu/news/science... #NMRchat 🧲
FSU chemist elected to prestigious society for advancing magnetic resonance, supporting next generation of scientists
A Florida State University faculty member has been elected to a prestigious scientific organization for his innovation in magnetic resonance, a scientific
news.fsu.edu
February 26, 2025 at 2:58 PM