Cage Metal Complexes: Synthesis, X-ray Structure, and Spectral and Redox Behavior of the First Hybrid Iron(II) Clathrochelatoscorpionate and Its Pyrazoloxime-Armed Macrocyclic Intermediate3



Invited for the cover of this issue is the group of Yan Voloshin at Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences. The image shows the X-ray structure of the first hybrid clathrochelatoscorpionate with an encapsulated iron(II) ion.

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How did the collaboration on this project start?

The Russian and Ukrainian teams have been collaborating substantially for more than twenty years. This collaboration includes constant exchange of young researchers and joint supervision of their Ph.D. work as well as scientific studies and joint presentations of the best results in scientific forums.

Did serendipity play a part in this work?

Well, we did see a structural similarity between metal scorpionates [tris(pyrazolate)s with a cross-linking boron atom] and clathrochelates with an encapsulated metal ion; encapsulating macrobicyclic ligands usually contain tripodal, boron-capped apical fragment(s).

What was the biggest surprise in this work?

We isolated and structurally characterized not only the target cage complex but also its pyrazoloxime-armed macrocyclic intermediate. Typically, such complexes are very reactive and easily undergo a macrobicyclization to give clathrochelates.

What other topics are you working on at the moment?

Other topics of our collaborative work are the synthesis of efficient clathrochelate electrocatalysts for hydrogen production and the design of clathrochelate-based transcription inhibitors as antiviral and anticancer drug candidates (the so-called “topological drugs”) as well as new (radio)diagnostic and (radio)therapeutic compounds with an encapsulated metal ion (including radioactive ions) for 11B-NCT treatment and 99mTc radiotherapy.


We thank the Russian Academy of Sciences (RAS), Russian Foundation for Basic Research (RFBR) – State Fund for Fundamental Researches (SFFR) (Russian – Ukrainian collaborative program), and the Marie Curie International Incoming Fellowship (IIF) Scheme of the 7th EU Framework Program for financial support.

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