Work

Crystalline Molecular Cleft Clathrates

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide A rigid bis(urea) molecular cleft ( BU1 ) based on the cis diastereomer of a rigid isophorone-derived spacer forms solid-state inclusion complexes with a range of small molecular guests. Larger guests can be accommodated by a shift in orientation to open up crystalline channels while retaining the same overall hydrogen-bonded topology. The introduction of molecular flexibility to give BU2, which possesses a methylene spacer, destroys the host–guest complexation behavior and restores the more conventional urea α-tape packing, giving viscous solutions due to columnar aggregation. Crystallization of both BU1 and BU2 from a mixture of cis and trans diastereomeric forms is highly diastereoselective with the cis isomers being significantly less soluble. Isolation of a trans isomer of BU2 from crystallization of cis -depleted mother liquor reveals an unusual intramolecular hydrogen bond arrangement, explaining its greater solubility.

Source: Crystal Growth & Design

DOI: 10.1021/acs.cgd.4c00928

Authors: Abbie V. Lynch, Toby J. Blundell, Jonathan W. Steed

Institution: Durham University

Language: English

Topic: Crystallography and molecular interactions

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: Diamond Light Source, Durham University