Cryptophanes are molecular receptors known for their complexation properties of various substrates. Over the last fifteen years, cryptophanes were the subject of numerous studies for they can be used to obtain biosensors for xenon MRI. This field has experienced significant growth and advances to the point were in vivo applications are now envisioned, provided that large amounts of biosensors can be synthesized. More recently, polyphenolic cryptophanes have been studied for their ability to encapsulate monovalent metallic cations like Cs⁺ and Tl⁺ in aqueous solution. This could lead to applications for depollution of contaminated water sources but would require, once again, the synthesis of large amounts of cryptophanes.

The work carried out during this thesis focus on the conception and the synthesis of new molecular platforms that could either be used to obtain new hyperpolarized xenon biosensors or to encapsulate monovalent metallic cations as Cs⁺ and Tl⁺. Synthetic routes have been developed to produce good amounts of a variety of new hydrosoluble molecular platforms designed for each application. The encapsulation properties of these new host molecules were studied through NMR of the encapsulated nucleus, circular dichroism or isothermal calorimetry. In each case, the new platforms meet the expected requirements thus opening the door for the envisioned applications.