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Helicity control of a polyaromatic coordination capsule through stereoselective CH-π interactions.

ABSTRACT: Although square-planar ML₄ units are essential building blocks for coordination cages and capsules, the non-covalent control of the chirality and helicity of the resultant nanostructures is quite difficult. Here we report the helicity control of an M₂L₄ polyaromatic capsule, formed from metal ions with square-planar coordination geometry and bent bispyridine ligands, through stereoselective CH-π interactions with monosaccharide derivatives. Thanks to host-guest CH-π multi-interactions, one molecule of various permethylated monosaccharides is quantitatively bound by the capsule in water (K _a up to >10⁸ M^-1). In the polyaromatic cavity, among them, the selective binding of a β-glucose derivative (>80 : 20 ratio) is demonstrated from a mixture of the α/β-glucoses, through the equatorial-selective recognition of the anomeric (C1) group. A similar stereoselective binding is accomplished from an α/β-galactose mixture. Interestingly, single equatorial/axial configurations on the bound monosaccharides can regulate the helical conformation of the capsule in water, confirmed by CD, NMR, and theoretical analyses. An intense capsule-based Cotton effect is exclusively observed upon encapsulation of the permethylated α-glucose (>20-fold enhancement as compared to the β-glucose derivative), via the induction of a single-handed host helicity to a large extent. Inverse capsule helicity is induced by the binding of a β-galactose derivative under the same conditions.

SUBMITTER: Kishida N

PROVIDER: S-EPMC11339976 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature

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Helicity control of a polyaromatic coordination capsule through stereoselective CH-π interactions.

Kishida Natsuki N Sasafuchi Hayate H Sawada Tomohisa T Yoshizawa Michito M

Chemical science 20240705 33

Although square-planar ML4 units are essential building blocks for coordination cages and capsules, the non-covalent control of the chirality and helicity of the resultant nanostructures is quite difficult. Here we report the helicity control of an M2L4 polyaromatic capsule, formed from metal ions with square-planar coordination geometry and bent bispyridine ligands, through stereoselective CH-π interactions with monosaccharide derivatives. Thanks to host-guest C ...[more]

PMID: 39183906

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Helicity control of a polyaromatic coordination capsule through stereoselective CH-π interactions.

Publications

Helicity control of a polyaromatic coordination capsule through stereoselective CH-π interactions.

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