Cavitands are specialized molecular structures designed to create a cavity or pocket that can selectively host smaller molecules or ions. They are often made from organic compounds and can be engineered to have specific shapes and sizes, allowing them to interact with guest molecules in unique ways. This selectivity makes cavitands useful in various fields, including chemistry and materials science. These structures are part of a broader category known as supramolecular chemistry, which studies how molecules interact and assemble through non-covalent bonds. Cavitands can be used in applications such as drug delivery, sensing, and catalysis, where their ability to encapsulate guest molecules can enhance performance and efficiency.