Molecular hosts are specialized molecules that can encapsulate or bind other smaller molecules, known as guests. These hosts often have specific shapes and chemical properties that allow them to selectively interact with certain guest molecules, forming stable complexes. This interaction can be used in various applications, including drug delivery and sensing. The study of molecular hosts is a key area in supramolecular chemistry, which focuses on the interactions between molecules. Examples of molecular hosts include crown ethers, cyclodextrins, and metal-organic frameworks. These structures can enhance the solubility, stability, and bioavailability of guest molecules in different environments.