We developed a metalloporphyrin-based molecular container capped with a calix[4]arene, and its rigid cavity distinguished the slight structural differences in the aromatic guests.

Low-molecular-mass organic gelators (LMOG), tris(phenylisoxazolyl)benzenes, were synthesized, and their self-assembling behavior was examined using 1H NMR and UV–vis absorption spectroscopies. They turned into a gel in both nonpolar and highly polar solvents such as methylcyclohexane, ether, acetone, dimethylsulfoxide, etc. Field emission scanning electron microscopy (FESEM) observation of the xerogels of 1 and 3 possessing the saturated alkyl chains revealed that well-developed straight fibers were formed, whereas the unsaturated termini of the alkyl chains of 2 promoted the formation of both the right- and left-handed helical fibers. The self-association behavior of 1, 2, and 5 in solution were investigated using 1H NMR and UV–vis spectroscopies. The flat aromatic compound 1 stacked in a columnar fashion along its C3 axis via π–π stacking interactions. The assemblies were regulated by the peripheral alkyl substituents; the saturated alkyl groups facilitated the assemblies while terminal double bonds impeded the intermolecular association, and the branched substituents obviously interfered in the formation of the stacks, probably due to steric requirements. Theoretical calculations suggest that the three dipoles of the isoxazole groups adopt the circular array. The conformational search of the hexameric stacks of 4 using MacroModel V9.1 gave rise to two major conformers: one is nonhelical and the other is helical. Further detailed structural analysis of the assemblies of chiral 5 using circular dichroism (CD) measurements indicated that their assemblies adopt helical structures in solution. CD spectra and DFT calculations revealed that R-5 forms a left-handed supramolecular helicate. The coassembly of R- and S-5 displayed chiral amplification, since the chiral information from 5 was transferred to the supramolecular chirality of the helical assemblies of 1. A small amount of optically active 5 provided enough chiral stimulus to produce a remarkable chiral response and supramolecular helical structures of 1.

Calix[4]arene-based triple helicates take up an achiral part of chiral guests; the chiral center outside the cavity causes the asymmetric induction of their supramolecular helicity.

S-shaped tetrakisporphyrin 2 forms supramolecular polymeric assemblies via a complementary affinity of its bisporphyrin units in solution. The self-association constant determined by applying the isodesmic model is >106 L mol−1, which suggests that a sizable polymer forms at millimolar concentrations at room temperature. The electron deficient aromatic guest (TNF) binds within the molecular clefts provided by the bisporphyrin units via a charge-transfer interaction. This guest complexation completely disrupts supramolecular polymeric assembly. The long, fibrous fragments of the polymeric assemblies were characterized by atomic-force microscopy imaging of a film cast on a mica surface. The polymeric assemblies have lengths of >1μm and show a coiled structure with a higher level of organization. The approach discussed in this report concerning the quick preparation of supramolecular polymeric assemblies driven by noncovalent forces sets the stage for the preparation of a previously undescribed class of macromolecular porphyrin architectures.

Tris(phenylisoxazolyl)benzene stacks in a columnar fashion to form helical fibers that act as an organogelator, and the supramolecular chirality is asymmetrically induced in the presence of a tiny amount of a chiral source in solution.

A new octadentate cavitand forms a stable dimeric molecular capsule via metal-coordination, creating a large and elaborate three-dimensional cavity in which large aromatic guests are accommodated to form supramolecular complexes.

We developed a metalloporphyrin-based molecular container capped with a calix[4]arene, and its rigid cavity distinguished the slight structural differences in the aromatic guests.

Calix[4]arene-based triple helicates take up an achiral part of chiral guests; the chiral center outside the cavity causes the asymmetric induction of their supramolecular helicity.

Tris(phenylisoxazolyl)benzene stacks in a columnar fashion to form helical fibers that act as an organogelator, and the supramolecular chirality is asymmetrically induced in the presence of a tiny amount of a chiral source in solution.