Hexacaesium trichloride hexacyanoferrate(III) monohydrate, Cs6Cl3[Fe(C
N)(6)].H2O, is a novel type of compound which contains two different a
nions. The crystal structure consists of alternating layers, A {Cs+, C
l-, [Fe(CN)(6)](3-), H2O} and B (Cs+, Cl-), stacked perpendicularly to
the b axis. The octahedral complex ion has m point symmetry. The wate
r molecules of solvation are disordered and form hydrogen bonds (O-H .
.. Cl and O-H ... N) within layer A. The Cs+ ions have coordination nu
mbers six to eight.