Synthesis of dome-shaped cyclophane type macrotricyclic anion receptor molecules

Tracking the absence of anion–π interactions in modified [23](1,3,5)cyclophanes: insights from computation

[2₃](1,3,5)Cyclophanes containing 1,3,5-triazine and 1,3,5-triphosphinine planar rings present different degrees of aromaticity as well as σ-donor and π-acceptor abilities.

Nanopatterned superlattices in self-assembled C2 -symmetric oligodimethylsiloxane-based benzene-1,3,5-tricarboxamides

The synthesis of C3 - and C2 -symmetric benzene-1,3,5-tricarboxamides (BTAs) containing well-defined oligodimethylsiloxane (oDMS) and/or alkyl side chains has been carried out. The influence of the bulkiness of the oDMS chains in the aggregation behavior of dilute solutions of the oDMS-BTAs in methylcyclohexane was studied by temperature-dependent UV spectroscopy. The formation of hierarchically self-assembled aggregates was observed at different BTA concentrations, the tendency of aggregation increases by shortening or removing oDMS chains. Chiral BTAs were investigated with circular dichroism (CD) spectroscopy, showing a stronger tendency to aggregate than the achiral ones. Majority rules experiments show a linear behavior consistent with the existence of a high mismatch penalty energy. The most efficient oDMS-BTAs organogelators have the ability to form stable organogels at 5 mg mL(-1) (0.75 wt %) in hexane. Solid-state characterization techniques indicate the formation of an intermolecular threefold hydrogen bonding between adjacent molecules forming thermotropic liquid crystals, exhibiting a hexagonal columnar organization from room temperature to above 150 °C. A decrease of the clearing temperatures was observed when increasing the number and length of the oligodimethylsiloxane chains. In addition to the three-fold hydrogen bonding that leads to columnar liquid crystalline phase, segregation between the oDMS and aliphatic chains takes place in the BTA functionalized with two alkyl and one oDMS chain leading to a superlattice within the hexagonal structure with potential applications in lithography.

Benzene-1,3,5-tricarboxamide: a versatile ordering moiety for supramolecular chemistry

After their first synthesis in 1915 by Curtius, benzene-1,3,5-tricarboxamides (BTAs) have become increasingly important in a wide range of scientific disciplines. Their simple structure and wide accessibility in combination with a detailed understanding of their supramolecular self-assembly behaviour allow full utilization of this versatile, supramolecular building block in applications ranging from nanotechnology to polymer processing and biomedical applications. While the opportunities in the former cases are connected to the self-assembly of BTAs into one-dimensional, nanometer-sized rod like structures stabilised by threefold H-bonding, their multivalent nature drives applications in the biomedical field. This review summarises the different types of BTAs that appeared in the recent literature and the applications they have been evaluated in. Currently, the first commercial applications of BTAs are emerging. The adaptable nature of this multipurpose building block promises a bright future.

Anion binding in covalent and self-assembled molecular capsules

This critical review describes selected examples extracted from the extensive literature generated during the past 42 years on the topic of anion binding in molecular capsules. The goal of including anions in molecular capsules emerges from the idea of incorporating the traits exhibited by biological receptors into synthetic ones. At the outset of this research area the capsules were unimolecular. The scaffold of the receptor was designed to covalently link a series of functional groups that could converge into a cavity and to avoid its collapse. The initial examples involved the encapsulation of one monoatomic spherical anion. With time, the cavity size of the receptor was increased and encapsulation of polyatomic anions and co-encapsulation became a reality. Synthetic economy fueled the use of aggregates of self-complementary molecules rather than one large molecule as capsules. The main purpose of this review is to give a general overview of the topic which might be of interest to supramolecular or non supramolecular chemists alike (149 references).

Synthesis, characterization, and anti-bacterial efficacy of some novel cyclophane amide

Synthesis of macrocyclic di, tetra- and hexaamides with aza and oxy linkages has been achieved and the inhibitory activity of cyclophane amides against human pathogenic bacteria well documented.