Guanidinium cations and azobenzene-4,4'-disulfonate (ABDS) dianions form a host lattice with a bilayer architecture in the presence of 1,4- dibromobenzene (DBB), 1,4-divinylbenzene (DVB), 1-nitronaphthalene (NN), and nitrobenzene (NB) guest molecules. The guests occupy one-dimensional pores in bilayer galleries created by ABDS dianions, which behave as 'pillars' that connect opposing hydrogen-bonded guanidinium-sulfonate (GS) sheets. This contrasts with our previous observation of a high porosity 'brick' framework that crystallized with these guests when the pillar was biphenyl-4,4'- disulfonate (BPDS). The reversion to the bilayer framework upon changing to ABDS can be attributed to the increased length of this pillar. Whereas the four guests are too large to fit in the pores of an ideal bilayer framework constructed from BPDS, they can be accommodated in bilayer galleries of increased height provided by the longer ABDS pillars. The control of framework architecture in this manner demonstrates that the solid-state structure of these materials can be rationally manipulated by systematic, stepwise adjustments to the size of the host components and of the guests. The ability to tune the pore volume of these frameworks so that different guests can be included, while retaining the essential structural features of the GS hosts, provides a versatile route to the synthesis of functional clathrates.
ASJC Scopus subject areas
- Colloid and Surface Chemistry