The Largest Supertetrahedral Oxychalcogenide Nanocluster and Its Unique Assembly

Supertetrahedral oxychalcogenide
Tn nanoclusters
(NCs, n denotes the number of metal-chalcogen layers)
integrate chemically distinct but ordered oxygen and chalcogen sites
in zinc-blend-type “quantum dots”. They therefore offer
a new level of control over various properties of semiconducting materials.
So far, few such structures are known, and the cluster size is also
limited to only T4 with 20 metal sites. Herein, we report an unusual
oxysulfide T5 nanocluster with 35 metal sites. It has unprecedented
In–O@In–S “core–shell” nanostructure
and is also the largest supertetrahedral oxychalcogenide NC. Through
cocrystallization, we further demonstrate that such oxychalcogenide
NCs can be assembled to form multidimensional structures. In addition
to N-donor imidazolates that help to form a 3-D structure with chiral
quartz net, the O-donor benzenetricarboxylate (BTC) has also been
found to successfully organize such T5 NCs. It is worth noting that
no carboxylate ligands have been shown earlier for assembling chalcogenide
clusters, despite their prevalence in MOFs. Given the wide availability
of O-donor ligands, this work introduces a versatile platform with
promise for a new generation of semiconducting inorganic–organic
hybrid materials.