UPenn SCXRD Facility

Another one for the books! Always a great time seeing old friends and making new ones! #ACA2025

Great thoughts! We have been doing a ton of continuing studies with this system and are varying things like light exposure, crystal size and temperature! We have been able to get full conversion by just adjusting the sample/camera light in the diffractometer!

4f-orbital covalency enables a single-crystal-to-single-crystal ring-opening isomerization in a CeIV–cyclopropenyl complex - Nature Chemistry Computational and spectroscopic studies of molecular lanthanide complexes have implicated 4f orbitals in metal–ligand bonding interactions. Now, a comparative study of isostructural d-block, actinide ...

Congrats to Brett and the Schelter lab! A very cool solid state single crystal isomerization that was tracked on one crystal over two weeks and 50 sequential collections! @pennchemistry.bsky.social www.nature.com/articles/s41...

George M. Sheldrick (1942-2025) - European Crystallographic Association It is with a heavy heart, that we must announce the passing of George Michael Sheldrick. Everyone in crystallography knows George as a giant in the development of computing methods […]

The CCDC team are saddened to learn that George Sheldrick has passed away.

His impact in #Crystallography was immense; from the SHELX software used globally, to teaching, structures, journals, and more.

More by the ECA here: ccdc-info.com/41gvV3M

Sheldrick’s SHELX From code on a Titan to becoming the titan of crystal structure determination

A giant of modern crystallography has passed. George Sheldrick was the author of the SHELX series of programs (among others) for structure solution and refinement of both small-molecule and macromolecular crystal structures.
www.chemistryworld.com/opinion/shel...

George Sheldrick will be missed🕯️🕯️🕯️#SHELX #crystallography #education

Professor Amos B. Smith iii

We are deeply saddened to share that our friend and colleague Professor Amos B. Smith III has passed away. Amos joined Penn in 1973 and was a mainstay in our organic chemistry division. He recently celebrated 50 years of service to @upenn.edu @pennsas.bsky.social.

Beautiful (Kelly) green crystals after an Eagles W! #GoBirds

Molecular Phosphide Complexes of Zirconium Molecular ZrIV phosphides are extremely rare, with no examples containing a one-coordinated and terminal triple-bonded phosphorus atom. We report here an isolable and relatively stable Zr phosphide complex, [(PN)2Zr≡P{μ2-Na(OEt2)}]2 (4), stemming from a cyclometalated Zr-hydride, [(PN)(PN′)Zr(H)] (2), and NaPH2. Complex 2 is prepared from two- or one-electron reductions of precursors [(PN)2ZrCl2] (1) or metastable ZrIII[(PN)2ZrCl], respectively. Oxidation of 2 with ClCPh3 (2 equiv) or I2 (1 equiv) resulted in re-formation of the PN ligand and isolation of the ZrIV complexes [(PN)2ZrX2] (X = Cl, 1; X = I, 3), whereas addition of a weak acid to 2 allowed us to intercept the hydrido-halide intermediate [(PN)2Zr(I)(H)] (X = Cl, I) spectroscopically before conversion to 1 or 3. Complex 2 exchanged with D2 (1 atm) to fully deuterate the methylene all ortho-methyl groups of the PN and PN′ ligands and the hydride. Discrete salts of 4 can be readily prepared from Na+ encapsulation with the crown ether 1,4,7,10,13,16-hexaoxacyclooctadecane (18-C-6) or cryptand 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane (222-Kryptofix) to form [Na(18-C-6)(THF)2][(PN)2Zr≡P] (5) and [Na(222-Kryptofix)][(PN)2Zr≡P] (6), respectively, which were structurally and spectroscopically characterized. Compounds 4–6 demonstrate exceptionally short Zr≡P bonds (4, 2.3270(18) Å; 5, 2.291(3) Å; 6, 2.2989(17) Å) and highly downfield 31P NMR spectral resonances (4, 819 ppm; 5 and 6, 927 and 955 ppm) in accord with a terminal phosphide ligand. The Zr≡P motif in 4–6 can be stabilized via coordination to a softer Tl+ ion to form a nonsolvated phosphide [(PN)2Zr≡P{μ2-Tl}]2 (7), exhibiting a phosphide resonance at ∼711 ppm.

New paper from the Mindiola lab! Novel Zirconium phosphide complexes. You know for a fact that the cryptands and crown ethers were incredibly disordered 🤷‍♂️

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

Concise Synthesis of (−)-Veratramine and (−)-20-iso-Veratramine via Aromative Diels–Alder Reaction A concise and convergent synthesis of the isosteroidal alkaloids veratramine and 20-iso-veratramine has been accomplished. A Horner–Wadsworth–Emmons olefination joins two chiral building blocks of app...

Check out our paper on veratramine and isosteroidal alkaloids, now published in JACS.

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

Biomimetic Synthesis of Azorellolide via Cyclopropylcarbinyl Cation Chemistry A concise synthesis of the complex diterpene azorellolide, inspired by speculations on biosynthetic cationic cascades, is presented. The approach, guided by computation, relies on the intramolecular interception of a cyclopropylcarbinyl cation by an appended carboxylate. The successful execution of this strategy was achieved through acid-catalyzed isomerization of a β-lactone in competition with a type I dyotropic rearrangement.

Azorellolide! How can you not work on a natural product that starts with "Azo"?
I have to say my respect for carbocations has enormously gown through this project. They are just too high in energy and have too many options. But you can tame them!
pubs.acs.org/doi/10.1021/...

Diimine–Dioxime Acenaphthene Cobalt Complexes: Characterization of the Novel cis Coordination Mode During the synthesis of a new family of diimine–dioxime acenaphthene cobalt complexes a novel cis coordination mode was observed and fully characterized. The preference for the cis vs. trans coordina....

New publication from a Schelter lab alum!

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

Isonitrile Insertion into Titanium Neopentylidene Alkyl Complexes Yields a Bifurcated Pathway to Form κ1-N-vinylamido or κ2-C,N-azaalleneyl Fragments Three organometallic ligand scaffolds resulting from the insertion of 1-adamantyl isonitrile (C≡NAd; Ad = C10H15) into titanium neopentylidene complexes, [(PNP)Ti═CHtBu(X)] are described herein. Treatment of the titanium neopentylidene complex (PNP)Ti═CHtBu(OTf) (1-OTf, PNP– = N[2-PiPr2-4-methylphenyl]2–, OTf = trifluoromethanesulfonate–) with one equivalent of C≡NAd leads to the formation of a titanium η2-C,N-ketenimine, (PNP)Ti(η2-C,N-AdNCCHtBu)(OTf) (2-OTf). However, when the titanium neopentylidene neopentyl complex (PNP)Ti═CHtBu(CH2tBu) (1-Np) is added one equivalent of C≡NAd, a titanium neopentylidene κ1-N-vinylamido complex (PNP)Ti═CHtBu(κ1-N-AdNCHCHtBu) (3) is formed. In contrast, the titanium neopentylidene methyl complex (PNP)Ti═CHtBu(CH3) (1-Me) reacts with one equivalent of C≡NAd to produce a rare chelating κ2-C,N-azaalleneyl ligand, in the complex (PNP)Ti(κ2-C,N-AdNCCtBu) (4), with concurrent extrusion of methane. Independently, it is shown that treatment of 2-OTf with one equivalent of neopentyl lithium (LiNp, Np– = CH2tBu) or a half equivalent of dimethyl magnesium (MgMe2) smoothly forms complex 3 or 4, respectively, and suggests that the η2-C,N-ketenimine ligand in 2-OTf might be an intermediate ligand enroute to the neopentylidene κ1-N-vinylamido or κ2-C,N-azaalleneyl complexes. Complexes 2-OTf, 3 and 4 have been structurally and spectroscopically characterized and a proposed mechanism for the formation of complexes 3 and 4 is also described.

New publication from the Mindiola lab featuring some neat Ti complexes! @pennchemistry.bsky.social #chemsky
pubs.acs.org/doi/10.1021/...

Sheeeeesh, she’s a beaut Clark… #Chemsky

#CSDWrapped report showing the structure for CSD entry FIYXOE.

Hi @upennxtal.bsky.social - here's your #CSDWrapped!

Promotional graphic with social media icons for Instagram, X and BlueSky.

It's the most wonderful time of the year — #CSDWrapped is back!

Get a personalized summary of your published crystal structures from Oct23-Oct24.

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What’s my #CSDWrapped ? Publishing name is Michael R. Gau 🎉

New paper from 1st author, Vagelos Institute graduate fellow Boyang Zhang from the Schelter group and @pennchemistry.bsky.social, reports a simple, selective, and sustainable method for separating cobalt from nickel. Cobalt is a critical mineral used in lithium-ion batteries.
doi.org/10.1016/j.ch...

Concise Synthesis of (–)-Veratramine and (–)-20-epi-Veratramine via Aromative Diels-Alder Reaction A concise and convergent synthesis of the isosteroidal alkaloids veratramine and 20-epi-veratramine has been accom-plished. A Horner-Wadsworth-Emmons olefination joins two chiral building blocks of ap...

Check out our first foray into the fascinating world of isosteroidal alkaloids, arguably one of Nature’s most diverse natural product family:

chemrxiv.org/engage/chemr...

There are fews things that make me happier than a nice single crystal X-ray structure. Keep sliding them under my door!