Comparisons and Contrasts in a Complete Set of Alkali Metal Cumyl Structures Alkali-metal benzyl complexes derived from toluene are known to vary their metal–ligand coordination mode as a function of the alkali-metal, with the metal transitioning from a typical σ bond to the anionic CH2 for lithium toward an interaction with the delocalized pi system of the aromatic ring as the metal gets larger and softer. Here, by switching to cumene, we report the charge-localizing effect of replacing the hydrogen atoms at the formally carbanionic carbon CH2 with electron-donating methyl groups in C(Me)2. NMR spectroscopic studies reveal competitive ring-metalation occurs, at the meta and para positions, alongside α-metalation on using an alkyl lithium base, with the meta- and α-isomers crystallographically characterized as a solvated dimer and monomer, respectively. Using Lochmann-Schlosser type base pairs to access the heavier alkali-metal complexes unveils only α-metalation. The presence of the methyl groups limits the variation in metal–ligand bonding, their electron-donating properties forcing the delocalization of the negative charge into the ring resulting in M-Ph interactions and sp2 hybridization at the formally deprotonated α-carbon regardless of the metal used. Considerable variation in aggregation state is observed with monomeric (Na), polymeric (K, Cs) and tetrameric (Rb) motifs identified in the solid-state.

Continuing our campaign to study all the alkali metals in organometallic chemistry. Why don't you try this in your own studies? Our friends in Bern @evaheviagroup.bsky.social are!

Comparisons and Contrasts in a Complete Set of Alkali Metal Cumyl Structures | Inorg Chem pubs.acs.org/doi/10.1021/...

Thrilled to co-author this perspective article with Eva and David. Think we are only at the tip of the iceberg on what is possible with these heavier alkali metals.

Thx I will pass it on.

Molecular low-oxidation-state chemistry with tetra-anionic group 14 elements - Nature Synthesis Using a hydrocarbon-soluble Mg0 complex, the heavier tetrel elements silicon, germanium, tin and lead are reduced to their ultimate negative oxidation state −IV. Despite fulfilling the octet rule, tet...

Now online and open access:

Article by Sjoerd Harder & co-workers @harder-research.bsky.social

Molecular low-oxidation-state chemistry with tetra-anionic group 14 elements

www.nature.com/articles/s44...
#Chemsky

MOLECULAR ZINTL PHASES with tetra-anionic Si, Ge, Sn, Pb accessible using soluble form of Mg(0). Although all E(4-) anions are full valence-shell octets, they are highly reactive. Some are stable, some not. The Sn(-IV) complex is an 8e-reductant shorturl.at/InmD6 @natsynth.nature.com

More about:
⌬ This article: chemrxiv.org/doi/full/10....
⌬ This illustration: sceyence.artstation.com/projects/Nqd...
⌬ Sc·EYE·nce: linktr.ee/sc.eye.nce

I must admit, I never heard of Sc.EYE.nce but the picture is great - and yes, we also think the research is beautiful! Thanks Benjamin 👍

Matt, Imogen and Mickey’s paper detailing the synthesis and reactivity of the first neutral Al(I) trimer is out now in @natcomms.nature.com! Check it out here along with @mattdv-t.bsky.social’s ‘behind the paper’ article!

🤩

Last week: homogeneous redox-catalysis with Al(I)-Al(III) (Leo Liu Lab) Now: heterogeneous alkene hydrogenation with Al(0), earth’s most abundant metal. Observations and calculations point to reactivity at the metal surface. Preprint: shorturl.at/I9R0B Main group power 👍

Hauptgruppen‐ und Molekülchemie Im Jahr 2025 waren aller guten Dinge der Hauptgruppenchemie drei: ein dreifach geladenes Triborattrianion, ein Molekül mit linearer Al3-Einheit, das dritte Erdalkalimetall, das Stickstoff bindet, ein ...

Great to see this out! @fabiandankert.bsky.social and I summarise some of our favourite papers in main group chemistry over the last year

gdch.app/article/haup...

Hauptgruppen‐ und Molekülchemie Im Jahr 2025 waren aller guten Dinge der Hauptgruppenchemie drei: ein dreifach geladenes Triborattrianion, ein Molekül mit linearer Al3-Einheit, das dritte Erdalkalimetall, das Stickstoff bindet, ein ...

@townrowresearch.bsky.social and I summarized some recent developments in molecular main-group chemistry. A fun project with many beautiful new discoveries last year! 👨‍🔬👩‍🔬
The annual "Trendbericht" can i.e. be read here:
gdch.app/article/haup...

While traditionally used as stoichiometric reagents, #HeavierAlkaliMetalAmides have emerged as versatile #catalysts find out more in this #perspective with #DavidSancehzRoa @pubs.acs.org in collaboration with @remglasgow.bsky.social @unistrathclyde.bsky.social
pubs.acs.org/doi/10.1021/...

Boosting the Nucleophilicity of the Diphenylphosphide Anion with Crown Ether Supported Heavy Alkali Metals to Facilitate Highly Efficient Catalytic Alkene Isomerisation Here, we report a breakthrough study in catalytic alkene isomerisation using crown ether-supported alkali metal phosphides in which the activity increases sequentially and significantly as Group One ...

Ceasium Strikes again! 🚀🚀

Now published in @angewandtechemie.bsky.social with @remglasgow.bsky.social and Thomas Horsley Downie!

onlinelibrary.wiley.com/doi/10.1002/...

Thx Matt. Yes, ligand choice did the trick. HSAB principle? Mg takes the hard N and Ca the softer Ar.

FINALLY a complex of type LMg-CaL! This formally Mg(0)-Ca(II) complex shows a very long Mg-Ca bond with Mg(-)/Ca(+) polarization and is quite reactive! Our first 2026 paper is "In dear memory of Herbert Roesky" shorturl.at/tvi0C

Congratulations Rebecca, looking forward to some radically new chemistry!

QUESTION TO THE COMMUNITY: Since COVID it is very difficult to get GOOD (STRONG) glovebox gloves. And they are very expensive! Any tips where to get normally priced good gloves? You can also direct-mail me: sjoerd.harder@fau.de Thanks for your advice!

Happy to see this fun project with @kretschmerlab.bsky.social out.

Two gallium centers in close proximity led to some unexpected outcomes.

Thanks to everyone involved and congrats to the team!

Fantastic! Good news for Bonn and for Florian. I wish you a happy and fruitful future 👍

Rapid Intermolecular C–H Activation of Aromatic Substrates at a Cationic, Electrophilic Molybdenum(VI) Nitrido Complex: Mechanistic Nuance in C–H Amination When the cationic, octahedral terminal nitrido complex of Mo(VI) supported by a diborate pentadentate ligand is generated in the absence of trapping nucleophiles, it activates the C(sp2)–H bonds of si...

Rapid Intermolecular C–H Activation of Aromatic Substrates at a Cationic, Electrophilic Molybdenum(VI) Nitrido Complex: Mechanistic Nuance in C–H Amination | Journal of the American Chemical Society pubs.acs.org/doi/full/10....

Very pleased this work is out in JACS. Congrats Dr. Almquist!

TIRE CHANGE: First Mg(I) complex with a Cp* ligand enables facile ligand exchange. Reaction with RONa gives (BDI)Mg-MgOR and Cp*Na. This paves the way for syntheses of many new asymmetric Mg(I) complexes. @angew_chem onlinelibrary.wiley.com/doi/epdf/10....

Great cooperation with @KretschmerLab.bsky.social who took the lead. Happy to see that old work from my time in Essen is now published! t.co/gvpPNdCk3i

REDOX-REACTIVITY of Yb and Sm inverse sandwich benzene complexes. An interesting observation is that, depending on substrate, benzene(4-) can reduce Sm(III) to Sm(II). doi.org/10.1002/chem...

Silicon‐Based Azo Compound‐Mediated CO Activation and N2 Release A rare silicon(IV)-based azo compound featuring a Si─N═N─Si linkage was synthesized via the direct reaction of an organoazide with a silaiminyl–silylene precursor. This compound undergoes an unusual ...

Hey #ChemSky, need a read to start of the week? How about our latest #OpenAccess research article on ”Silicon-Based Azo Compound-Mediated CO Activation and N2 Release“ out now in @angewandtechemie.bsky.social: doi.org/10.1002/anie...

A Highly Reduced Magnesium Dicobalt Complex for the Hydrogenation of Tri- and Tetra-Substituted Alkenes The reaction of [K(thf)0.33][Co(η4-cod)2] (E; cod = 1,5-cyclooctadiene) with 0.5 equiv of MgCl2 led to the isolation of the magnesium dicobalt complex Mg[Co(η4-cod)2]2 (1). Complex 1 forms a tight ionic complex in the solid state and in toluene solution due to electrostatic interactions between the Mg2+ cation and the [Co(η4-cod)2]− anions. The complex is a successful precatalyst for the hydrogenation of sterically challenging tri- and tetra-substituted alkenes, surpassing the catalytic capabilities of related alkali metal and β-diketiminate magnesium complexes.

Check out our latest publication: A Highly Reduced Magnesium Dicobalt Complex for the Hydrogenation of Tri- and Tetra-Substituted Alkenes | Organometallics pubs.acs.org/doi/10.1021/...

Ending the week on a high! Check out our comparison of manganate and magnesiate now published in ChemComm! Great team effort @bathchem.bsky.social with @tobiaskramer.bsky.social in understanding these elusive bimetallics!

Cesium showing its tricks again! Great stuff 👍

CAPTURING CHALCOGENIDES: A soluble Mg(0) metal crown complex reduces and captures chalcogenes. Large anions Se(2-) and Te(2-) need ring enlargement. Highlight: a first molecular s-block metal telluride complex with nearly planar pentacoordinated Te(2-). shorturl.at/n4TUm

Thx Rab, I will pass it on to the team