MS32-P16 Guest loading into highly flexible MOF pores driven by molecular recognition: a stepwise SCXRD investigationMOFs (Metal Organic Frameworks) are a large class of ultraporous crystalline polymers deriving from the self-assembly of metallic ions or clusters with polytopic organic ligands. The high modularity of their synthesis allows a fine tuning of their porosity, making possible the confinement of molecular species of different shape and size.
Starting from the pioneeristic concept of crystalline-sponge method , we here propose a systematic way to embed small molecular aggregates inside home-made porous crystalline materials, with the aim of exploring the structural aspects of nanoconfinement and stabilizing the guest molecules inside the cavities of the structure. The challenge of this idea stands in the possibility to neatly “freeze”, within a crystal, ordered supramolecular clusters of molecules that would form a liquid in their natural state at ambient conditions, and visualize their supramolecular aggregation, at different loading time.
In particular, we propose an unprecedent stepwise characterization of the evolution of the guest loading into metal-organic framework driven by host-guest interactions , focusing on the description of supramolecular aggregate of the guests inside the pores guided by guest-guest interactions. The MOF crystals were soaked for different time into the pure liquid guest and sequentially characterized via SCXRD.
The guest we focused on is eugenol, which is a volatile phenolic constituent of clove essential oil obtained from Eugenia caryophyllata buds and leaves. It is a functional ingredient of numerous products which have been used in the pharmaceutical, agro-food and cosmetic industry. The wide range of eugenol activities derived from it antimicrobial, anti-inflammatory, analgesic and antioxidant properties.
 Y. Inokuma, S. Yoshioka, J. Ariyoshi, T. Arai, Y. Hitora, K. Takada, S. Matsunaga, K.Rissanen and M. Fujita, 2013, Nature, 495, 461–466.Keywords: MOF, molecular recognition