We stumbled on a very curious observation in the summer of 2018 with DABQDI molecules provided by Olivier Siri‘s team.
![](https://jhell.imipolex.biz/wp-content/uploads/2021/05/DABQDI_Au111_105.png)
![STM chain manipulation](https://jhell.imipolex.biz/wp-content/uploads/2021/05/DABQDI-manipulation.gif)
While evaluating its experimental suitability for 1d coordination with metals, which has already proven to be fruitful, we noticed the molecules forming chain-like structures even before we introduced metal adatoms.
The low temperature SPM results are sublime: unusual mechanical stability, distinctive intermolecular bonding, and near-Fermi electronic states lighting up at the ends of the chains.
It took an extraordinary cast of theorists hailing from Pavel’s core group, FZU, Charles, Reykjavik, & Madrid Universities to unravel this puzzle and explain these observations as concerted proton tunneling causing a delocalization of electrons.
“Significance of Nuclear Quantum Effects in Hydrogen Bonded Molecular Chains”, ACS Nano, 2021. 10.1021/acsnano.1c02572