High Quality Content by WIKIPEDIA articles! A clathrate, clathrate compound or cage compound is a chemical substance consisting of a lattice of one type of molecule trapping and containing a second type of molecule. The name clathrate complex used to refer only to the inclusion complex of hydroquinone, but recently it has been adopted for many other weak composites which consist of a host molecule (forming the basic frame) and a guest molecule (held in the host molecule by inter-molecular interaction). Clathrates are also called host-guest complexes, inclusion compounds, and adducts (chiefly in the case of urea and thiourea). They used to be called molecular compounds.