Assembly and Post-Modification of a Metal–Organic Nanotube for Highly Efficient Catalysis

A metal–organic nanotube (MONT) was synthesized
by linking
up the bent organic ligands and the tetra-coordinated zinc cations
under mild conditions. Structural analysis revealed that the MONT
has a very large exterior wall diameter of 4.91 nm and an interior
channel diameter of 3.32 nm. Interlocking of the nanotubes gives rise
to a 3D chiral framework containing 1D helical cylindered channels
with diameter of 2.0 nm. The MONT has very interesting property by
synergizing the functionality of nanotubes, metal–organic frameworks
(MOFs), and N-heterocyclic carbenes (NHCs). The dye adsorption experiments
demonstrate that the channels of the MONTs are accessible to large
reagents typically used for catalysis. The postmodification of the
MONT can be easily operated by unmarking the imidazolium moieties
in the channel walls, which was conducted as a highly active heterogeneous
catalyst for Suzuki–Miyaura and Heck coupling reactions, hydrogenation
of olefins and nitrobenzene, while the constituent elements are less
efficient for these reactions under the same conditions.