Polycatenane gels have attracted extensive attention due to their high
degree of freedom and mobility. However, the synthesis of
poly[2]catenane gels reported to date all rely on the polymer as the
backbone. Herein, we prepared poly[2]catenane gels based on entirely
sequential assembly of small molecules. Monomer M1 with two
unclosed rings was first prepared, which self-assembled to form
supramolecular polymers(SPs) via hydrogen bonding and π-π
interactions. Upon adding small molecule monomers M2
and M3 with aldehyde groups, ring closing of SPs occurred due
to the amino groups in the SPs reacted with M2 to form imine
bonds. In addition, M3, which has twice the number of aldehyde
groups as M2, enabled SPs to ring-close, causing the proceeding
of crosslinking process at the same time. Thus linear SPs were
transformed into poly[2]catenane gel networks. Due to the presence
of hydrogen bonds in the poly[2]catenane gel, the gel also possessed
stimulus responsiveness and self-healing properties.
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