Postclustering Dynamic Covalent Modification for Chirality Control and Chiral Sensing

Cluster-based functional
materials are appealing, because clusters
are well-defined building units that can be rationally incorporated
for the tuning of structures and properties. Postclustering modification
(PCM) allows for tailoring properties through the structural modification
of a cluster with preorganized funtional groups. By introducing aldehydes
into a robust gold–silver cluster via a protection–deprotection
process, we manage to synthesize a new cluster bearing six reactive
sites, which are available for PCM through dynamic covalent imine
bonds formation with chiral monoamines. Chirality is transferred from
the amine to the gold–silver cluster. The homochirality of
the resulted cluster has been confirmed by X-ray structural determination
and CD spetroscopy. Intense CD signals make it practical for chiral
recognition and ee value determination of chiral
monoamines. The strategy of prefunctionalizing of cluster and the
concept of PCM open a broader prospect for cluster design and applications.