Three neutral π‐associated [2]catenanes have been synthesised from the oxidative dimerisation of terminal acetylene‐equipped electron‐deficient diimides in the presence of an electron‐rich dinaptho‐crown template (below). The mutual recognition of the complementary donor–acceptor building blocks is revealed in solid‐state analyses of a precatenane inclusion complex and a [2]catenane. Dynamic movement of the interlocked rings has been examined by 1H NMR spectroscopy, and a model has been developed to explain the observed photophysics.

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The overlap of pi-complementary planar organic frameworks is used to direct the assembly of extended columns of alternating donor and acceptor units. The electron-rich partner, hexaalkoxytriphenylene, is a familiar mesogen, while the electron-accepting complement is mellitic triimide, a new C(3)-symmetric building block that may be readily alkylated at its periphery without compromising its electron-accepting ability. A cocrystal of examples of the two components demonstrates pi-facial overlap of the complementary aromatic surfaces. Preparation of a series of alkylated derivatives of each component allowed the study of an array of 1:1 stoichiometry mixtures. For the optimum donor-acceptor organized mesophases within this grid, temperature stability ranges of well over 100 degrees C are observed, some of which extend below room temperature. X-ray analysis confirms the formation of hexagonally packed, alternating, donor-acceptor columns within each of the observed mesophases. The dramatic effect on mesophase formation and stability engendered via donor-acceptor organization within discrete columns is discussed in terms of the interplay of forces leading to mesophase formation, and the potential to tune mesophase characteristics via manipulation of these factors.

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[reaction: see text] A series of diimide-based macrocycles have been prepared using Mitsunobu-mediated alkylation as the macrocyclization step. These macrocycles could not be incorporated into [2]catenanes using previously established building blocks and coupling methodology. However, when one of the macrocycle syntheses was conducted in the presence of a dinaphtho crown ether, catenane formation was achieved. This result is discussed in terms of the ability of the components to establish intermolecular C-H...O hydrogen-bonding contacts.

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