Compression in encapsulated carboxylic acid homodimers

- DFT study on five hydrogen bonded carboxylic acid dimers encapsulated in three cages.
- Attractive interactions between guests and capsules's walls stabilize encapsulation.
- Stabilization of encapsulation although severe confinement hinders dimer formation.
- Increasing size of the encapsulated dimers results in shorter hydrogen-bond lengths.

A density functional theory study has been carried out on five carboxylic acid homodimers, free and encapsulated, in order to study the effect of encapsulation or compression. Attractive interactions between the guests and the walls of the capsules stabilize encapsulation even in cases of severe confinement where formation of dimers is unfavorable. Larger hydrogen bonds are calculated for the encapsulated than the isolated dimers except for the case of the bulkiest dimer considered, where encapsulation leads to shortening of the hydrogen bond. Shorter hydrogen-bond lengths with increasing size of the encapsulated dimers are calculated, in agreement with experimental work.

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