Caesium propano-ate monohydrate.

Caesium propano-ate monohydrate, Cs(+)·C(3)H(5)O(2) (-)·H(2)O, is composed of two symmetry-independent Cs(+) cations, which are situated on the special position 4e of space group P 2(1) m, one symmetry-independent propano-ate mol-ecule in a general position and a pair of water mol-ecules also situated on special position 4e. Two pairs of these symmetry-independent cations, four propano-ate mol-ecules and two pairs of symmetry-independent water mol-ecules form a repeat unit. These units form columns that are directed along the c axis and possess symmetry mm2. There are four such columns passing through each unit cell. Each column is inter-connected to its neighbours by four bifurcated three-centred O(w)-H⋯O(p) (w = water, p = propano-ate) hydrogen bonds of moderate strength. There are also four intra-molecular O(w)-H⋯O(p) hydrogen bonds of moderate strength within each column. One Cs(+) cation is coordinated by six oxygen atoms (two water and four carboxyl-ate) in a trigonal-prismatic geometry, while the other Cs(+) cation is coordinated by four water and four carboxyl-ate O atoms in a tetra-gonal-prismatic arrangement.