In coordination chemistry, hydration isomerism is a kind of isomerism that is observed in some solids. Hydration isomers have identical formula but differ with respect to the numbers of water ligands.

Examples

edit

One example is the pair [CrCl(H2O)5]Cl2•H2O and [Cr(H2O)6]Cl3.[1] The former has one water of crystallization but the latter does not.

Another example is the pair of titanium(III) chlorides, [Ti(H2O)6]Cl3 and [Ti(H2O)4Cl2]Cl(H2O)2. The former is violet and the latter, with two molecules of water of crystallization, is green.[2]

References

edit
  1. ^ Barbier, J. P.; Kappenstein, C.; Hugel, R. (1972). "The Hydration Isomers of Chromium(III) Chloride". Journal of Chemical Education. 49 (3): 204. Bibcode:1972JChEd..49..204B. doi:10.1021/ed049p204.
  2. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 965. ISBN 978-0-08-037941-8.