High-surface-area mesoporous germanium from oxidative polymerization of the deltahedral [Ge₉]^4- cluster: Electronic structure modulation with donor and acceptor molecules

A study has reported an advanced route to hexagonal mesoporous germanium through the slow oxidative polymerization of the deltahedral (Ge ₉)^4- clusters. This route does not require an external oxidant nor linking agent and occurs in the presence of the cationic surfactant N-eicosane-N,N-dimethyl-N-(2-hydroxethyl)ammonium bromide (EDMHEAB) as a structure-directing agent. A novel form of mesoporous germanium (NU-Ge-1) can be stabilized, which possesses a large surface area and can readily absorb organic aromatic species. The study also demonstrated that the pore surface of mesoporous Ge is sensitive towards adsorbates with electron-donor and -acceptor properties, exhibiting reversible changes in its electronic structure. The electronic structure of the Ge network can also be altered in a controllable manner by absorbing in its interior molecules with donor and acceptor properties that can engage in charge-transfer interactions with the inorganic framework.