3D Anionic Silicate Covalent Organic Framework with srs Topology

The
synthesis of 3D covalent organic frameworks (COFs) adopting
novel topologies is challenging, and so far 3D COFs have only been
reported for nets based on building blocks with tetrahedral geometry.
We demonstrate the targeted synthesis of an anionic 3D COF crystallizing
in a three-coordinated srs net by exploiting a recently
developed linkage for the formation of anionic silicate COFs based
on hypercoordinate silicon nodes. The framework, named SiCOF-5, was
synthesized by reticulating dianionic hexacoordinate [SiO6]2– nodes with triangular triphenylene building
blocks and adopts a two-fold interpenetrated srs-c net
with an overall composition of Na2­[Si­(C18H6O6)] (where C18H6O6 is triphenylene-2,3,6,7,10,11-hexakis­(olate)). A key requirement
for the crystallization of SiCOF-5 was the careful control over the
nucleation and growth rate by gradual generation of the silicon source
during the course of the reaction.