Metal Organic Nanocapsules as Two-Dimensional Network Building Blocks

Metal–organic
frameworks (MOFs) are a class of porous materials
with a wide variety of applications, including molecular adsorption
and separation. Recently, the first MOF based on the zinc-seamed pyrogallol[4]­arene
nanocapsule as a secondary building unit was reported. The zinc-seamed
nanocapsules are linked together with 4,4′-bipyridine, which
is a divergent ligand commonly used in the synthesis of MOFs. In an
effort to identify other likely candidates for nanocapsular linking,
electronic structure calculations were performed to determine energetic
and geometric properties of (Zn­(C2O2H3)2)1,2Y model complexes, which have been shown
previously to reliably model the zinc coordination sphere found in
the nanocapsules. Here, Y represents one of 17 divergent ligands with
N, S, or O electron-donating atoms. MOFs were synthesized and characterized
from two of the ligands suggested as most suitable for further experimental
study.