A
clathrate is a
chemical substance consisting of a
lattice that traps or contains molecules. The word
clathrate is derived from the
Latin clatratus meaning
with bars or a lattice. Traditionally, clathrate compounds are polymeric and completely envelop the guest molecule, but in modern usage clathrates also include
host-guest complexes and
inclusion compounds. According to
IUPAC, clathrates are "Inclusion compounds in which the guest molecule is in a cage formed by the host molecule or by a lattice of host molecules."