Scientists synthesize new organometallic sandwich compound capable of holding more electrons

https://phys.org/news/2023-09-scientists-organometallic-sandwich-compound-capable.html

"metallocenes sandwich many different elements forming variety of compounds... accommodate formation of complexes with up to 20 (18 is most stable) electrons... However now added 2 more to a 19-electron and created 21-electron metallocene, stable in solution and solid states and long storage... create novel polymers, glucometers, perovskite solar cells, catalysis and unprecedented organometallic chemistry"