In inorganic chemistry and materials chemistry, a ternary compound or ternary phase is a chemical compound containing three different elements.
While some ternary compounds are molecular, e.g. chloroform (), more typically ternary phases refer to extended solids. The perovskites are a famous example.
Binary phases, with only two elements, have lower degrees of complexity than ternary phases. With four elements, quaternary phases are more complex.
The number of isomers of a ternary compound provide a distinction between inorganic and organic chemistry: "In inorganic chemistry one or, at most, only a few compounds composed of any two or three elements were known, whereas in organic chemistry the situation was very different." "the chemistry of the entire mineral world informs us that chemical complexity can easily be accommodated within structural simplicity." The example of zircon is cited, where various metal atoms are replaced in the same crystal structure. "The structural entity ... remains ternary in character and is able to accommodate an enormous range of chemical elements." The great variety of ternary compounds is therefore reduced to relatively few structures: "By dealing with approximately ten ternary structural groupings we can cover the most important structures of science and technology specific to the non-metallics world. It is a remarkable instance of nature's simplexity."
See also
- Binary compound
- Mitscherlich's law of isomorphism
- Quaternary phase