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Evolution of supramolecular chemistry as a concept of pre-organized small entities held together by weak intermolecular forces has established possibilities for the so-called “bottom-up” approach to create smart materials at molecular level. The building blocks have to be encoded with essential information required for spontaneous self-assembly. Hence, the synthesis of monomers often can be quite challenging and time consuming. A new level of elegance and simplicity has to be achieved to develop building blocks. Herein, chiral C2-symmetric bicyclo[3.3.1.]nonane framework encompassing self-complementary moieties was used as a synthon for the self-assembly. The manipulation of size and spatial arrangement of the substituents provided the means to control the orthogonal stacking of monomers to transform the discrete capsules into tubular polymers. The host-guest properties of the resulting aggregates were probed by encapsulation of fullerene C60 within the well-defined cavity. The dynamic nature of the concave capsule comprising tetraphenyl porphyrin moieties was demonstrated in the complexation experiments using guest C60. The conformational changes of the system were achieved by guest induced cooperative effect of the tautomerization from the keto to enol form alongside CH-π interactions in order to provide suitable cavity for C60 guest molecule. Tubular hydrogen-bonded polymer comprising electronically decoupled n- and p-type channels was synthesized as a potential supramolecular n,p-heterojunction material. The cooperative effect of directional hydrogen bonding between isocytosine moieties and π-π stacking between planar tetrathiafulvalenes ensures high degree of internal order with well-aligned n/p channels which is essential for functional materials exhibiting high mobility of charge carries. |
