Structural studies on inclusion compounds and solvent sorption behavior of gradually elongated wheel-and-axle-type diol hosts featuring lateral benzo[b]thiophene units

• The syntheses of gradually elongated wheel-and-axle-type hosts are presented.
• A longer central spacer unit does not improve the general inclusion behavior.
• Most efficient solvent inclusion in the crystal is found for a biphenyl spacer.
• The ratio of vapor absorption is notably high for the CC–Ph–CC spacer.
• A structure memory effect has been shown.

Based on the wheel-and-axle design strategy, a series of six new clathrate hosts featuring two di(benzo[b]thien-2-yl)hydroxymethyl units attached to both ends of a central linear building element of varying length have been synthesized and their capability to form crystalline inclusion compounds with a fixed range of organic solvents are reported. X-ray crystal structures of relevant inclusion compounds have been determined and are comparatively discussed involving structural modification of the host molecules. Organic vapor sorption behavior of the host compounds coated as solid films on the quartz crystal of a QCM device has been studied. Significant differences in the affinities towards solvent vapors dependent both on structural and polarity properties of host and solvent are observed, indicating potential application as mass sensitive materials.

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