Harder Research Group

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

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⌬ 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

Thx Robert. The beauty of low valent group 2 chemistry!

THIS CHALLENGING SYNTHESIS completes the (BDI)Ae-(benzene)-Ae(BDI) series (Ae = Mg, Ca, Sr, Ba) with Ba. We show trends in stability, structure, bonding and reactivity. Reacting like (BDI)Ba-Ba(BDI) this is the first Ba(I) synthon. shorturl.at/ZdToA @chemicalscience.rsc.org

P4 REDUCTION generally results in multi-nuclear Zintl anions: P8(2-), P4(2-) or P7(3-). Reaction with a soluble Mg(0) complex gave full reduction to P(3-). Latter anion serves as a triple base, a three-fold nucleophile or 3e-reducing agent. onlinelibrary.wiley.com/doi/epdf/10.10