Hydrated electrons as nodes in porous clathrate hydrates

We investigate the structures of hydrated electrons (e(aq)(-)) in one of water's solid phases, namely, clathrate hydrates (CHs). Using density functional theory (DFT) calculations, DFT-based ab initio molecular dynamics (AIMD), and path-integral AIMD simulations with periodic boundary conditions, we find that the structure of the e(aq)(-)@node model is in good agreement with the experiment, suggesting that an e(aq)(-) could form a node in CHs. The node is a H2O defect in CHs that is supposed to be composed of four unsaturated hydrogen bonds. Since CHs are porous crystals that possess cavities that can accommodate small guest molecules, we expect that these guest molecules can be used to tailor the electronic structure of the e(aq)(-)@node, and it leads to experimentally observed optical absorption spectra of CHs. Our findings have a general interest and extend the knowledge of e(aq)(-) into porous aqueous systems.

Automated summary

We investigate the structures of hydrated electrons (e(aq)(-)) in clathrate hydrates (CHs), a solid phase of water. Using various computational methods, we find that e(aq)(-) can form a node in CHs, which is a H2O defect composed of four unsaturated hydrogen bonds. The guest molecules in CHs can alter the electronic structure of the e(aq)(-)@node, leading to experimentally observed optical absorption spectra. These findings extend our understanding of hydrated electrons in porous aqueous systems.