Frank-Kasper and other superlattice formations in a series of \textit{AB}$_{n}$ type giant molecules precisely constructed by functionalized nanoparticles.

A novel set of precisely defined \textit{AB}$_{n}$ type giant molecules has been designed and synthesized. They are consisted of one functionalized hydrophilic polyhedral oligomeric silsesquioxane (DPOSS) ($A)$ connected with different numbers of hydrophobic BPOSS cages ($B$, $n=$1-7). With variation of the number of coordinated hydrophobic POSS $B$, different superlattice structures could be formed at a sub-20-nm scale. For example, the superlattice structure of DPOSS-BPOSS$_{\mathrm{1}}$ can form a normal lamellar structure while DPOSS-BPOSS$_{\mathrm{2\thinspace }}$changes to a double-dyroids phase. With increasing the number of BPOSS, hexagonal close packed cylinder phase can be formed by DPOSS-BPOSS$_{\mathrm{3}}$. For DPOSS-BPOSS$_{\mathrm{4,\thinspace }}$DPOSS-BPOSS$_{\mathrm{5\thinspace }}$and DPOSS-BPOSS$_{\mathrm{6}}$, all of these giant molecules show the Frank-Kasper A15 phase, while DPOSS-BPOSS$_{\mathrm{7\thinspace }}$can assembly into a sigma phase. With deep understanding of this set of model \textit{AB}$_{n}$ type giant molecules with functional ``nano-atoms'', it is promising to construct new generations of giant molecules for further development of functional materials with desired structures and macroscopic properties.